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[PATCH] Move REPACK (CONCURRENTLY) test out of stock regression tests 455+ messages / 2 participants [nested] [flat]
* [PATCH] Move REPACK (CONCURRENTLY) test out of stock regression tests @ 2026-04-22 09:22 Álvaro Herrera <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Álvaro Herrera @ 2026-04-22 09:22 UTC (permalink / raw) These tests sometimes run with wal_level=minimal, which does not allow to run REPACK (CONCURRENTLY). Move them to test_decoding, which is ensured to run with high enough wal_level. Discussion: https://postgr.es/m/[email protected] --- contrib/test_decoding/Makefile | 2 +- contrib/test_decoding/expected/repack.out | 30 +++++++++++++++++++++++ contrib/test_decoding/meson.build | 1 + contrib/test_decoding/sql/repack.sql | 25 +++++++++++++++++++ src/test/regress/expected/cluster.out | 29 +++------------------- src/test/regress/sql/cluster.sql | 13 +++------- 6 files changed, 65 insertions(+), 35 deletions(-) create mode 100644 contrib/test_decoding/expected/repack.out create mode 100644 contrib/test_decoding/sql/repack.sql diff --git a/contrib/test_decoding/Makefile b/contrib/test_decoding/Makefile index acbcaed2feb..0111124399a 100644 --- a/contrib/test_decoding/Makefile +++ b/contrib/test_decoding/Makefile @@ -5,7 +5,7 @@ PGFILEDESC = "test_decoding - example of a logical decoding output plugin" REGRESS = ddl xact rewrite toast permissions decoding_in_xact \ decoding_into_rel binary prepared replorigin time messages \ - spill slot truncate stream stats twophase twophase_stream + repack spill slot truncate stream stats twophase twophase_stream ISOLATION = mxact delayed_startup ondisk_startup concurrent_ddl_dml \ oldest_xmin snapshot_transfer subxact_without_top concurrent_stream \ twophase_snapshot slot_creation_error catalog_change_snapshot \ diff --git a/contrib/test_decoding/expected/repack.out b/contrib/test_decoding/expected/repack.out new file mode 100644 index 00000000000..70039d824af --- /dev/null +++ b/contrib/test_decoding/expected/repack.out @@ -0,0 +1,30 @@ +-- Test REPACK (CONCURRENTLY). +-- This isn't strictly about decoding, but it involves logical decoding +-- and requires to be run under higher than minimal wal_level, so we can't +-- have it in the main regression test suite. +-- Ownership of partitions is checked +CREATE TABLE ptnowner(i int unique not null) PARTITION BY LIST (i); +CREATE INDEX ptnowner_i_idx ON ptnowner(i); +CREATE TABLE ptnowner1 PARTITION OF ptnowner FOR VALUES IN (1); +CREATE ROLE regress_ptnowner; +CREATE TABLE ptnowner2 PARTITION OF ptnowner FOR VALUES IN (2); +ALTER TABLE ptnowner1 OWNER TO regress_ptnowner; +SET SESSION AUTHORIZATION regress_ptnowner; +ALTER TABLE ptnowner1 REPLICA IDENTITY USING INDEX ptnowner1_i_key; +REPACK (CONCURRENTLY) ptnowner1; +RESET SESSION AUTHORIZATION; +ALTER TABLE ptnowner OWNER TO regress_ptnowner; +CREATE TEMP TABLE ptnowner_oldnodes AS + SELECT oid, relname, relfilenode FROM pg_partition_tree('ptnowner') AS tree + JOIN pg_class AS c ON c.oid=tree.relid; +SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a + JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C"; + relname | ?column? +-----------+---------- + ptnowner | t + ptnowner1 | t + ptnowner2 | t +(3 rows) + +DROP TABLE ptnowner; +DROP ROLE regress_ptnowner; diff --git a/contrib/test_decoding/meson.build b/contrib/test_decoding/meson.build index cf5b74cf1ab..ac655853d26 100644 --- a/contrib/test_decoding/meson.build +++ b/contrib/test_decoding/meson.build @@ -34,6 +34,7 @@ tests += { 'replorigin', 'time', 'messages', + 'repack', 'spill', 'slot', 'truncate', diff --git a/contrib/test_decoding/sql/repack.sql b/contrib/test_decoding/sql/repack.sql new file mode 100644 index 00000000000..bf66bb441ac --- /dev/null +++ b/contrib/test_decoding/sql/repack.sql @@ -0,0 +1,25 @@ +-- Test REPACK (CONCURRENTLY). +-- This isn't strictly about decoding, but it involves logical decoding +-- and requires to be run under higher than minimal wal_level, so we can't +-- have it in the main regression test suite. + + +-- Ownership of partitions is checked +CREATE TABLE ptnowner(i int unique not null) PARTITION BY LIST (i); +CREATE INDEX ptnowner_i_idx ON ptnowner(i); +CREATE TABLE ptnowner1 PARTITION OF ptnowner FOR VALUES IN (1); +CREATE ROLE regress_ptnowner; +CREATE TABLE ptnowner2 PARTITION OF ptnowner FOR VALUES IN (2); +ALTER TABLE ptnowner1 OWNER TO regress_ptnowner; +SET SESSION AUTHORIZATION regress_ptnowner; +ALTER TABLE ptnowner1 REPLICA IDENTITY USING INDEX ptnowner1_i_key; +REPACK (CONCURRENTLY) ptnowner1; +RESET SESSION AUTHORIZATION; +ALTER TABLE ptnowner OWNER TO regress_ptnowner; +CREATE TEMP TABLE ptnowner_oldnodes AS + SELECT oid, relname, relfilenode FROM pg_partition_tree('ptnowner') AS tree + JOIN pg_class AS c ON c.oid=tree.relid; +SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a + JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C"; +DROP TABLE ptnowner; +DROP ROLE regress_ptnowner; diff --git a/src/test/regress/expected/cluster.out b/src/test/regress/expected/cluster.out index 71270134985..b767316cf6b 100644 --- a/src/test/regress/expected/cluster.out +++ b/src/test/regress/expected/cluster.out @@ -552,8 +552,6 @@ ALTER TABLE ptnowner1 OWNER TO regress_ptnowner; SET SESSION AUTHORIZATION regress_ptnowner; CLUSTER ptnowner USING ptnowner_i_idx; ERROR: permission denied for table ptnowner -ALTER TABLE ptnowner1 REPLICA IDENTITY USING INDEX ptnowner1_i_key; -REPACK (CONCURRENTLY) ptnowner1; RESET SESSION AUTHORIZATION; ALTER TABLE ptnowner OWNER TO regress_ptnowner; CREATE TEMP TABLE ptnowner_oldnodes AS @@ -562,30 +560,7 @@ CREATE TEMP TABLE ptnowner_oldnodes AS SET SESSION AUTHORIZATION regress_ptnowner; CLUSTER ptnowner USING ptnowner_i_idx; WARNING: permission denied to execute CLUSTER on "ptnowner2", skipping it --- still can't repack without a replica identity -ALTER TABLE ptnowner1 REPLICA IDENTITY DEFAULT; -REPACK (CONCURRENTLY) ptnowner1; -ERROR: cannot process relation "ptnowner1" -HINT: Relation "ptnowner1" has no identity index. RESET SESSION AUTHORIZATION; -SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a - JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C"; - relname | ?column? ------------+---------- - ptnowner | t - ptnowner1 | f - ptnowner2 | t -(3 rows) - -SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a - JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C"; - relname | ?column? ------------+---------- - ptnowner | t - ptnowner1 | f - ptnowner2 | t -(3 rows) - DROP TABLE ptnowner; DROP ROLE regress_ptnowner; -- Test CLUSTER with external tuplesorting @@ -731,6 +706,10 @@ COMMIT; -- -- REPACK -- +-- Note we cannot test working REPACK (CONCURRENTLY) here, because the +-- tests could be run with wal_level=minimal, so those tests are +-- elsewhere. +-- ---------------------------------------------------------------------- -- REPACK handles individual tables identically to CLUSTER, but it's worth -- checking if it handles table hierarchies identically as well. diff --git a/src/test/regress/sql/cluster.sql b/src/test/regress/sql/cluster.sql index 6746236ffec..a22c75282ee 100644 --- a/src/test/regress/sql/cluster.sql +++ b/src/test/regress/sql/cluster.sql @@ -262,8 +262,6 @@ CREATE TABLE ptnowner2 PARTITION OF ptnowner FOR VALUES IN (2); ALTER TABLE ptnowner1 OWNER TO regress_ptnowner; SET SESSION AUTHORIZATION regress_ptnowner; CLUSTER ptnowner USING ptnowner_i_idx; -ALTER TABLE ptnowner1 REPLICA IDENTITY USING INDEX ptnowner1_i_key; -REPACK (CONCURRENTLY) ptnowner1; RESET SESSION AUTHORIZATION; ALTER TABLE ptnowner OWNER TO regress_ptnowner; CREATE TEMP TABLE ptnowner_oldnodes AS @@ -271,14 +269,7 @@ CREATE TEMP TABLE ptnowner_oldnodes AS JOIN pg_class AS c ON c.oid=tree.relid; SET SESSION AUTHORIZATION regress_ptnowner; CLUSTER ptnowner USING ptnowner_i_idx; --- still can't repack without a replica identity -ALTER TABLE ptnowner1 REPLICA IDENTITY DEFAULT; -REPACK (CONCURRENTLY) ptnowner1; RESET SESSION AUTHORIZATION; -SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a - JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C"; -SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a - JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C"; DROP TABLE ptnowner; DROP ROLE regress_ptnowner; @@ -346,6 +337,10 @@ COMMIT; -- -- REPACK -- +-- Note we cannot test working REPACK (CONCURRENTLY) here, because the +-- tests could be run with wal_level=minimal, so those tests are +-- elsewhere. +-- ---------------------------------------------------------------------- -- REPACK handles individual tables identically to CLUSTER, but it's worth -- 2.47.3 --5vljmhsecqh6fok5-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --=-=-=-- ^ permalink raw reply [nested|flat] 455+ messages in thread
* [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. @ 2026-05-06 07:38 Antonin Houska <[email protected]> 0 siblings, 0 replies; 455+ messages in thread From: Antonin Houska @ 2026-05-06 07:38 UTC (permalink / raw) Currently, decoding session that relies on database-specific xl_running_xacts WAL records can also use some information of cluster-wide records and vice versa. Although this approach might reduce the total number of xl_running_xacts records, it's simply not correct. SnapBuildProcessRunningXacts() now decides at the very beginning whether particular record can be used or not. --- src/backend/replication/logical/snapbuild.c | 55 +++++++++++++-------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c index c8309b96ed4..b9661b7d70a 100644 --- a/src/backend/replication/logical/snapbuild.c +++ b/src/backend/replication/logical/snapbuild.c @@ -1157,6 +1157,39 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact ReorderBufferTXN *txn; TransactionId xmin; + /* + * Each decoding session should use either cluster-wide snapshots or + * database-specific ones, but not both. Since the latter can have more + * recent value of oldestRunningXid, builder->xmin could go backwards if + * it was followed by cluster-wide snapshot - see the ->xmin adjustment + * below. + */ + if (!db_specific && OidIsValid(running->dbid)) + return; + + if (db_specific) + { + /* + * Make sure that we have the snapshots needed for startup, as well as + * those for regular cleanup: each time the cluster-wide snapshot is + * created (typically on slot creation or by checkpointer), the + * database-specific snapshot is requested here if the current session + * needs it. + */ + if (!OidIsValid(running->dbid)) + { + LogStandbySnapshot(MyDatabaseId); + + return; + } + /* + * Snapshots issued for other databases do not contain the information + * about transactions in our database. + */ + else if (running->dbid != MyDatabaseId) + return; + } + /* * If we're not consistent yet, inspect the record to see whether it * allows to get closer to being consistent. If we are consistent, dump @@ -1171,17 +1204,7 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact */ if (db_specific) { - /* - * If we must only keep track of transactions running in the - * current database, we need transaction info from exactly that - * database. - */ - if (running->dbid != MyDatabaseId) - { - LogStandbySnapshot(MyDatabaseId); - - return; - } + Assert(running->dbid == MyDatabaseId); /* * We'd better be able to check during scan if the plugin does not @@ -1198,16 +1221,6 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact else SnapBuildSerialize(builder, lsn); - /* - * Database specific transaction info may exist to reach CONSISTENT state - * faster, however the code below makes no use of it. Moreover, such - * record might cause problems because the following normal (cluster-wide) - * record can have lower value of oldestRunningXid. In that case, let's - * wait with the cleanup for the next regular cluster-wide record. - */ - if (OidIsValid(running->dbid)) - return; - /* * Update range of interesting xids based on the running xacts * information. We don't increase ->xmax using it, because once we are in -- 2.47.3 --tbdehtstrqwksfdh-- ^ permalink raw reply [nested|flat] 455+ messages in thread
end of thread, other threads:[~2026-05-06 07:38 UTC | newest] Thread overview: 455+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-04-22 09:22 [PATCH] Move REPACK (CONCURRENTLY) test out of stock regression tests Álvaro Herrera <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH 3/3] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]> 2026-05-06 07:38 [PATCH] Distinguish properly when database-specific transaction list should be used. Antonin Houska <[email protected]>
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