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[PATCH v1 1/2] Report wait event for cost-based vacuum delay
333+ messages / 4 participants
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* [PATCH v1 1/2] Report wait event for cost-based vacuum delay
@ 2020-03-21 01:47  Justin Pryzby <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Justin Pryzby @ 2020-03-21 01:47 UTC (permalink / raw)

---
 doc/src/sgml/monitoring.sgml    | 2 ++
 src/backend/commands/vacuum.c   | 2 ++
 src/backend/postmaster/pgstat.c | 3 +++
 src/include/pgstat.h            | 3 ++-
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 5bffdcce10..46c99a55b7 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -1507,6 +1507,8 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
           (<filename>pg_wal</filename>, archive or stream) before trying
           again to retrieve WAL data, at recovery.
          </entry>
+         <entry><literal>VacuumDelay</literal></entry>
+         <entry>Waiting in a cost-based vacuum delay point.</entry>
         </row>
         <row>
          <entry morerows="68"><literal>IO</literal></entry>
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index d625d17bf4..59731d687f 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -2019,7 +2019,9 @@ vacuum_delay_point(void)
 		if (msec > VacuumCostDelay * 4)
 			msec = VacuumCostDelay * 4;
 
+		pgstat_report_wait_start(WAIT_EVENT_VACUUM_DELAY);
 		pg_usleep((long) (msec * 1000));
+		pgstat_report_wait_end();
 
 		VacuumCostBalance = 0;
 
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index d29c211a76..742ec07b59 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -3824,6 +3824,9 @@ pgstat_get_wait_timeout(WaitEventTimeout w)
 		case WAIT_EVENT_RECOVERY_RETRIEVE_RETRY_INTERVAL:
 			event_name = "RecoveryRetrieveRetryInterval";
 			break;
+		case WAIT_EVENT_VACUUM_DELAY:
+			event_name = "VacuumDelay";
+			break;
 			/* no default case, so that compiler will warn */
 	}
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 851d0a7246..4db40e23cc 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -848,7 +848,8 @@ typedef enum
 	WAIT_EVENT_BASE_BACKUP_THROTTLE = PG_WAIT_TIMEOUT,
 	WAIT_EVENT_PG_SLEEP,
 	WAIT_EVENT_RECOVERY_APPLY_DELAY,
-	WAIT_EVENT_RECOVERY_RETRIEVE_RETRY_INTERVAL
+	WAIT_EVENT_RECOVERY_RETRIEVE_RETRY_INTERVAL,
+	WAIT_EVENT_VACUUM_DELAY,
 } WaitEventTimeout;
 
 /* ----------
-- 
2.17.0


--9jxsPFA5p3P2qPhR
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v1-0002-vacuum-to-report-time-spent-in-cost-based-delay.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH 1/2] Allow table AMs to define their own reloptions
@ 2025-03-01 16:59  Julien Tachoires <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Julien Tachoires @ 2025-03-01 16:59 UTC (permalink / raw)

With the help of the new routine 'relation_options', table access
methods can now define their own reloptions.

These options can be set via the following commands:
1. CREATE TABLE ... USING table_am
       WITH (option1='value1', option2='value2');
2. ALTER TABLE ...
       SET (option1 'value1', option2 'value2');
3. ALTER TABLE ... SET ACCESS METHOD table_am
       OPTIONS (option1 'value1', option2 'value2');

When changing table's access method, the settings from the former
table AM can be dropped (if not supported by the new table AM) via:
DROP option, or, updated via: SET option 'value'.

Before this commit, tables using different table AMs than heap were
able to use heap's reloptions (fillfactor, toast_tuple_target,
etc...). Now, this is not the case anymore: if the table AM needs
to have access to settings similar to heap ones, they must
explicitly define them.

This work is directly derived from SadhuPrasad's patch named:
v4-0001-PATCH-V4-Per-table-storage-parameters-for-TableAM.patch
---
 doc/src/sgml/ref/alter_table.sgml        |  13 +-
 doc/src/sgml/ref/create_table.sgml       |   3 +-
 src/backend/access/common/reloptions.c   |  66 ++++++++-
 src/backend/access/heap/heapam_handler.c |   2 +
 src/backend/commands/foreigncmds.c       |   2 +-
 src/backend/commands/tablecmds.c         | 180 ++++++++++++++++++++---
 src/backend/parser/gram.y                |   9 ++
 src/backend/postmaster/autovacuum.c      |  18 ++-
 src/backend/utils/cache/relcache.c       |  11 +-
 src/include/access/reloptions.h          |   6 +-
 src/include/access/tableam.h             |  10 ++
 src/include/commands/defrem.h            |   1 +
 12 files changed, 286 insertions(+), 35 deletions(-)

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index d63f3a621ac..e567aad4774 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -77,7 +77,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable>
     CLUSTER ON <replaceable class="parameter">index_name</replaceable>
     SET WITHOUT CLUSTER
     SET WITHOUT OIDS
-    SET ACCESS METHOD { <replaceable class="parameter">new_access_method</replaceable> | DEFAULT }
+    SET ACCESS METHOD { <replaceable class="parameter">new_access_method</replaceable> | DEFAULT } [ OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ] ) ]
     SET TABLESPACE <replaceable class="parameter">new_tablespace</replaceable>
     SET { LOGGED | UNLOGGED }
     SET ( <replaceable class="parameter">storage_parameter</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] )
@@ -758,7 +758,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="sql-altertable-desc-set-access-method">
-    <term><literal>SET ACCESS METHOD</literal></term>
+    <term><literal>SET ACCESS METHOD { <replaceable class="parameter">new_access_method</replaceable> | DEFAULT } [ OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ] ) ]</literal></term>
     <listitem>
      <para>
       This form changes the access method of the table by rewriting it
@@ -776,6 +776,15 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       causing future partitions to default to
       <varname>default_table_access_method</varname>.
      </para>
+     <para>
+      Specifying <literal>OPTIONS</literal> allows to change options for
+      the table when changing the table access method.
+      <literal>ADD</literal>, <literal>SET</literal>, and
+      <literal>DROP</literal> specify the action to be performed.
+      <literal>ADD</literal> is assumed if no operation is explicitly
+      specified.  Option names must be unique; names and values are also
+      validated using the table access method's library.
+     </para>
     </listitem>
    </varlistentry>
 
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 4a41b2f5530..ad642e55d22 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1552,7 +1552,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     Storage parameters for
     indexes are documented in <xref linkend="sql-createindex"/>.
     The storage parameters currently
-    available for tables are listed below.  For many of these parameters, as
+    available for tables are listed below. Each table may have different set of storage
+    parameters through different access methods. For many of these parameters, as
     shown, there is an additional parameter with the same name prefixed with
     <literal>toast.</literal>, which controls the behavior of the
     table's secondary <acronym>TOAST</acronym> table, if any
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 46c1dce222d..0d8ead7ce5d 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -25,6 +25,7 @@
 #include "access/reloptions.h"
 #include "access/spgist_private.h"
 #include "catalog/pg_type.h"
+#include "catalog/pg_am.h"
 #include "commands/defrem.h"
 #include "commands/tablespace.h"
 #include "nodes/makefuncs.h"
@@ -34,6 +35,7 @@
 #include "utils/guc.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
+#include "utils/syscache.h"
 
 /*
  * Contents of pg_class.reloptions
@@ -1388,7 +1390,7 @@ untransformRelOptions(Datum options)
  */
 bytea *
 extractRelOptions(HeapTuple tuple, TupleDesc tupdesc,
-				  amoptions_function amoptions)
+				  amoptions_function amoptions, reloptions_function reloptsfun)
 {
 	bytea	   *options;
 	bool		isnull;
@@ -1410,7 +1412,8 @@ extractRelOptions(HeapTuple tuple, TupleDesc tupdesc,
 		case RELKIND_RELATION:
 		case RELKIND_TOASTVALUE:
 		case RELKIND_MATVIEW:
-			options = heap_reloptions(classForm->relkind, datum, false);
+			options = table_reloptions(reloptsfun, InvalidOid, classForm->relkind,
+									   datum, false);
 			break;
 		case RELKIND_PARTITIONED_TABLE:
 			options = partitioned_table_reloptions(datum, false);
@@ -2040,7 +2043,8 @@ view_reloptions(Datum reloptions, bool validate)
 }
 
 /*
- * Parse options for heaps, views and toast tables.
+ * Parse options for heaps, views and toast tables. This is the implementation
+ * of relOptions for the access method heap.
  */
 bytea *
 heap_reloptions(char relkind, Datum reloptions, bool validate)
@@ -2070,6 +2074,62 @@ heap_reloptions(char relkind, Datum reloptions, bool validate)
 }
 
 
+/*
+ * Parse options for tables.
+ *
+ *	reloptsfun	Table AM's option parser function. Can be NULL if amid is
+ *				valid. In this case we load the new table AM and use its option
+ *				parser function.
+ *	amid		New table AM's Oid if any.
+ *	relkind		relation kind
+ *	reloptions	options as text[] datum
+ *	validate	error flag
+ */
+bytea *
+table_reloptions(reloptions_function reloptsfun, Oid amid, char relkind,
+				 Datum reloptions, bool validate)
+{
+	/* amid and reloptsfun are mutually exclusive */
+	Assert((!OidIsValid(amid) && (reloptsfun != NULL)) || \
+		   (OidIsValid(amid) && (reloptsfun == NULL)));
+
+	/* Parse/validate options using reloptsfun */
+	if (!OidIsValid(amid) && reloptsfun != NULL)
+	{
+		/* Assume function is strict */
+		if (!PointerIsValid(DatumGetPointer(reloptions)))
+			return NULL;
+
+		return reloptsfun(relkind, reloptions, validate);
+	}
+	/* Parse/validate options using the API of the new Table AM */
+	else if (OidIsValid(amid) && (reloptsfun == NULL))
+	{
+		const TableAmRoutine *routine;
+		HeapTuple	atuple;
+		Form_pg_am	aform;
+
+		atuple = SearchSysCache1(AMOID, ObjectIdGetDatum(amid));
+
+		if (!HeapTupleIsValid(atuple))
+			elog(ERROR, "cache lookup failed for access method %u", amid);
+
+		aform = (Form_pg_am) GETSTRUCT(atuple);
+		routine = GetTableAmRoutine(aform->amhandler);
+		ReleaseSysCache(atuple);
+
+		if (routine->relation_options != NULL)
+			return routine->relation_options(relkind, reloptions, validate);
+
+		return NULL;
+	}
+	else
+	{
+		/* Should not happen */
+		return NULL;
+	}
+}
+
 /*
  * Parse options for indexes.
  *
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index ac082fefa77..79f176bb7b8 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -24,6 +24,7 @@
 #include "access/heaptoast.h"
 #include "access/multixact.h"
 #include "access/rewriteheap.h"
+#include "access/reloptions.h"
 #include "access/syncscan.h"
 #include "access/tableam.h"
 #include "access/tsmapi.h"
@@ -2659,6 +2660,7 @@ static const TableAmRoutine heapam_methods = {
 	.index_build_range_scan = heapam_index_build_range_scan,
 	.index_validate_scan = heapam_index_validate_scan,
 
+	.relation_options = heap_reloptions,
 	.relation_size = table_block_relation_size,
 	.relation_needs_toast_table = heapam_relation_needs_toast_table,
 	.relation_toast_am = heapam_relation_toast_am,
diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c
index c14e038d54f..9dab5dfb999 100644
--- a/src/backend/commands/foreigncmds.c
+++ b/src/backend/commands/foreigncmds.c
@@ -62,7 +62,7 @@ static void import_error_callback(void *arg);
  * processing, hence any validation should be done before this
  * conversion.
  */
-static Datum
+Datum
 optionListToArray(List *options)
 {
 	ArrayBuildState *astate = NULL;
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 54ad38247aa..64b10a58d1c 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -677,6 +677,8 @@ static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel,
 								const char *tablespacename, LOCKMODE lockmode);
 static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode);
 static void ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace);
+static void ATExecSetAccessMethodOptions(Relation rel, List *defList, AlterTableType operation,
+										 LOCKMODE lockmode, Oid newAccessMethodId);
 static void ATExecSetRelOptions(Relation rel, List *defList,
 								AlterTableType operation,
 								LOCKMODE lockmode);
@@ -926,24 +928,6 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	if (!OidIsValid(ownerId))
 		ownerId = GetUserId();
 
-	/*
-	 * Parse and validate reloptions, if any.
-	 */
-	reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
-									 true, false);
-
-	switch (relkind)
-	{
-		case RELKIND_VIEW:
-			(void) view_reloptions(reloptions, true);
-			break;
-		case RELKIND_PARTITIONED_TABLE:
-			(void) partitioned_table_reloptions(reloptions, true);
-			break;
-		default:
-			(void) heap_reloptions(relkind, reloptions, true);
-	}
-
 	if (stmt->ofTypename)
 	{
 		AclResult	aclresult;
@@ -1046,6 +1030,29 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 			accessMethodId = get_table_am_oid(default_table_access_method, false);
 	}
 
+	/*
+	 * Parse and validate reloptions, if any.
+	 */
+	reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
+									 true, false);
+	switch (relkind)
+	{
+		case RELKIND_VIEW:
+			(void) view_reloptions(reloptions, true);
+			break;
+		case RELKIND_PARTITIONED_TABLE:
+			(void) partitioned_table_reloptions(reloptions, true);
+			break;
+		case RELKIND_RELATION:
+		case RELKIND_TOASTVALUE:
+		case RELKIND_MATVIEW:
+			(void) table_reloptions(NULL, accessMethodId, relkind, reloptions,
+									true);
+			break;
+		default:
+			(void) heap_reloptions(relkind, reloptions, true);
+	}
+
 	/*
 	 * Create the relation.  Inherited defaults and CHECK constraints are
 	 * passed in for immediate handling --- since they don't need parsing,
@@ -5527,6 +5534,9 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab,
 			if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
 				tab->chgAccessMethod)
 				ATExecSetAccessMethodNoStorage(rel, tab->newAccessMethod);
+
+			ATExecSetAccessMethodOptions(rel, (List *) cmd->def, cmd->subtype,
+										 lockmode, tab->newAccessMethod);
 			break;
 		case AT_SetTableSpace:	/* SET TABLESPACE */
 
@@ -16550,6 +16560,138 @@ ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, const char *tablespacen
 	tab->newTableSpace = tablespaceId;
 }
 
+/* SET, ADD or DROP options in ALTER TABLE SET ACCESS METHOD */
+static void
+ATExecSetAccessMethodOptions(Relation rel, List *options, AlterTableType operation,
+							 LOCKMODE lockmode, Oid newAccessMethodId)
+{
+	Oid			relid;
+	Relation	pgclass;
+	HeapTuple	tuple;
+	HeapTuple	newtuple;
+	Datum		datum;
+	bool		isnull;
+	Datum		newOptions;
+	Datum		repl_val[Natts_pg_class];
+	bool		repl_null[Natts_pg_class];
+	bool		repl_repl[Natts_pg_class];
+	List	   *resultOptions;
+	ListCell   *optcell;
+
+	pgclass = table_open(RelationRelationId, RowExclusiveLock);
+
+	/* Fetch heap tuple */
+	relid = RelationGetRelid(rel);
+	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relid);
+
+	/* Get the old reloptions */
+	datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, &isnull);
+
+	if (isnull)
+		datum = PointerGetDatum(NULL);
+
+	resultOptions = untransformRelOptions(datum);
+
+	foreach(optcell, options)
+	{
+		DefElem    *od = lfirst(optcell);
+		ListCell   *cell;
+
+		/* Search in existing options */
+		foreach(cell, resultOptions)
+		{
+			DefElem    *def = lfirst(cell);
+
+			if (strcmp(def->defname, od->defname) == 0)
+				break;
+		}
+
+		/*
+		 * It is possible to perform multiple SET/DROP actions on the same
+		 * option.  The standard permits this, as long as the options to be
+		 * added are unique.  Note that an unspecified action is taken to be
+		 * ADD.
+		 */
+		switch (od->defaction)
+		{
+			case DEFELEM_DROP:
+				if (!cell)
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("option \"%s\" not found",
+									od->defname)));
+				resultOptions = list_delete_cell(resultOptions, cell);
+				break;
+
+			case DEFELEM_SET:
+				if (!cell)
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("option \"%s\" not found",
+									od->defname)));
+				lfirst(cell) = od;
+				break;
+
+			case DEFELEM_ADD:
+			case DEFELEM_UNSPEC:
+				if (cell)
+					ereport(ERROR,
+							(errcode(ERRCODE_DUPLICATE_OBJECT),
+							 errmsg("option \"%s\" provided more than once",
+									od->defname)));
+				resultOptions = lappend(resultOptions, od);
+				break;
+
+			default:
+				elog(ERROR, "unrecognized action %d on option \"%s\"",
+					 (int) od->defaction, od->defname);
+				break;
+		}
+	}
+
+	newOptions = optionListToArray(resultOptions);
+
+	/*
+	 * If the new table access method was not explicitly defined, then use the
+	 * default one.
+	 */
+	if (!OidIsValid(newAccessMethodId))
+		newAccessMethodId = get_table_am_oid(default_table_access_method, false);
+
+	/* Validate new options via the new Table Access Method API */
+	(void) table_reloptions(NULL, newAccessMethodId, rel->rd_rel->relkind,
+							newOptions, true);
+
+	/* Initialize buffers for new tuple values */
+	memset(repl_val, 0, sizeof(repl_val));
+	memset(repl_null, false, sizeof(repl_null));
+	memset(repl_repl, false, sizeof(repl_repl));
+
+	if (newOptions != (Datum) 0)
+		repl_val[Anum_pg_class_reloptions - 1] = newOptions;
+	else
+		repl_null[Anum_pg_class_reloptions - 1] = true;
+
+	repl_repl[Anum_pg_class_reloptions - 1] = true;
+
+	/* Everything looks good - update the tuple */
+	newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
+								 repl_val, repl_null, repl_repl);
+
+	CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple);
+
+	InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel),
+							  InvalidOid);
+
+	ReleaseSysCache(tuple);
+
+	table_close(pgclass, RowExclusiveLock);
+
+	heap_freetuple(newtuple);
+}
+
 /*
  * Set, reset, or replace reloptions.
  */
@@ -16607,7 +16749,7 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
 	{
 		case RELKIND_RELATION:
 		case RELKIND_MATVIEW:
-			(void) heap_reloptions(rel->rd_rel->relkind, newOptions, true);
+			rel->rd_tableam->relation_options(rel->rd_rel->relkind, newOptions, true);
 			break;
 		case RELKIND_PARTITIONED_TABLE:
 			(void) partitioned_table_reloptions(newOptions, true);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 0b5652071d1..a96c9eb15f2 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2924,6 +2924,15 @@ alter_table_cmd:
 					n->name = $4;
 					$$ = (Node *) n;
 				}
+			/* ALTER TABLE <name> SET ACCESS METHOD <amname> [OPTIONS]*/
+			| SET ACCESS METHOD name alter_generic_options
+				{
+					AlterTableCmd *n = makeNode(AlterTableCmd);
+					n->subtype = AT_SetAccessMethod;
+					n->name = $4;
+					n->def = (Node *) $5;
+					$$ = (Node *)n;
+				}
 			/* ALTER TABLE <name> SET TABLESPACE <tablespacename> */
 			| SET TABLESPACE name
 				{
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 981be42e3af..202fddf2de9 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -332,6 +332,7 @@ static void FreeWorkerInfo(int code, Datum arg);
 
 static autovac_table *table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 											TupleDesc pg_class_desc,
+											reloptions_function reloptions,
 											int effective_multixact_freeze_max_age);
 static void recheck_relation_needs_vacanalyze(Oid relid, AutoVacOpts *avopts,
 											  Form_pg_class classForm,
@@ -346,7 +347,7 @@ static void relation_needs_vacanalyze(Oid relid, AutoVacOpts *relopts,
 static void autovacuum_do_vac_analyze(autovac_table *tab,
 									  BufferAccessStrategy bstrategy);
 static AutoVacOpts *extract_autovac_opts(HeapTuple tup,
-										 TupleDesc pg_class_desc);
+										 TupleDesc pg_class_desc, reloptions_function reloptions);
 static void perform_work_item(AutoVacuumWorkItem *workitem);
 static void autovac_report_activity(autovac_table *tab);
 static void autovac_report_workitem(AutoVacuumWorkItem *workitem,
@@ -2033,7 +2034,8 @@ do_autovacuum(void)
 		}
 
 		/* Fetch reloptions and the pgstat entry for this table */
-		relopts = extract_autovac_opts(tuple, pg_class_desc);
+		relopts = extract_autovac_opts(tuple, pg_class_desc,
+									   classRel->rd_tableam->relation_options);
 		tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
 												  relid);
 
@@ -2113,7 +2115,8 @@ do_autovacuum(void)
 		 * fetch reloptions -- if this toast table does not have them, try the
 		 * main rel
 		 */
-		relopts = extract_autovac_opts(tuple, pg_class_desc);
+		relopts = extract_autovac_opts(tuple, pg_class_desc,
+									   classRel->rd_tableam->relation_options);
 		if (relopts)
 			free_relopts = true;
 		else
@@ -2379,6 +2382,7 @@ do_autovacuum(void)
 		 */
 		MemoryContextSwitchTo(AutovacMemCxt);
 		tab = table_recheck_autovac(relid, table_toast_map, pg_class_desc,
+									classRel->rd_tableam->relation_options,
 									effective_multixact_freeze_max_age);
 		if (tab == NULL)
 		{
@@ -2706,7 +2710,8 @@ deleted2:
  * be a risk; fortunately, it doesn't.
  */
 static AutoVacOpts *
-extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc)
+extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc,
+					 reloptions_function reloptions)
 {
 	bytea	   *relopts;
 	AutoVacOpts *av;
@@ -2715,7 +2720,7 @@ extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc)
 		   ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_MATVIEW ||
 		   ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_TOASTVALUE);
 
-	relopts = extractRelOptions(tup, pg_class_desc, NULL);
+	relopts = extractRelOptions(tup, pg_class_desc, NULL, reloptions);
 	if (relopts == NULL)
 		return NULL;
 
@@ -2738,6 +2743,7 @@ extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc)
 static autovac_table *
 table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 					  TupleDesc pg_class_desc,
+					  reloptions_function reloptions,
 					  int effective_multixact_freeze_max_age)
 {
 	Form_pg_class classForm;
@@ -2759,7 +2765,7 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 	 * Get the applicable reloptions.  If it is a TOAST table, try to get the
 	 * main table reloptions if the toast table itself doesn't have.
 	 */
-	avopts = extract_autovac_opts(classTup, pg_class_desc);
+	avopts = extract_autovac_opts(classTup, pg_class_desc, reloptions);
 	if (avopts)
 		free_avopts = true;
 	else if (classForm->relkind == RELKIND_TOASTVALUE &&
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 559ba9cdb2c..fb3c8ee2f64 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -469,6 +469,7 @@ RelationParseRelOptions(Relation relation, HeapTuple tuple)
 {
 	bytea	   *options;
 	amoptions_function amoptsfn;
+	reloptions_function reloptsfn;
 
 	relation->rd_options = NULL;
 
@@ -480,13 +481,18 @@ RelationParseRelOptions(Relation relation, HeapTuple tuple)
 	{
 		case RELKIND_RELATION:
 		case RELKIND_TOASTVALUE:
-		case RELKIND_VIEW:
 		case RELKIND_MATVIEW:
+			reloptsfn = relation->rd_tableam->relation_options;
+			amoptsfn = NULL;
+			break;
+		case RELKIND_VIEW:
 		case RELKIND_PARTITIONED_TABLE:
+			reloptsfn = NULL;
 			amoptsfn = NULL;
 			break;
 		case RELKIND_INDEX:
 		case RELKIND_PARTITIONED_INDEX:
+			reloptsfn = NULL;
 			amoptsfn = relation->rd_indam->amoptions;
 			break;
 		default:
@@ -498,7 +504,8 @@ RelationParseRelOptions(Relation relation, HeapTuple tuple)
 	 * we might not have any other for pg_class yet (consider executing this
 	 * code for pg_class itself)
 	 */
-	options = extractRelOptions(tuple, GetPgClassDescriptor(), amoptsfn);
+	options = extractRelOptions(tuple, GetPgClassDescriptor(),
+								amoptsfn, reloptsfn);
 
 	/*
 	 * Copy parsed data into CacheMemoryContext.  To guard against the
diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h
index dfbb4c85460..37f51d0f1c2 100644
--- a/src/include/access/reloptions.h
+++ b/src/include/access/reloptions.h
@@ -21,6 +21,7 @@
 
 #include "access/amapi.h"
 #include "access/htup.h"
+#include "access/tableam.h"
 #include "access/tupdesc.h"
 #include "nodes/pg_list.h"
 #include "storage/lock.h"
@@ -237,7 +238,8 @@ extern Datum transformRelOptions(Datum oldOptions, List *defList,
 								 bool acceptOidsOff, bool isReset);
 extern List *untransformRelOptions(Datum options);
 extern bytea *extractRelOptions(HeapTuple tuple, TupleDesc tupdesc,
-								amoptions_function amoptions);
+								amoptions_function amoptions,
+								reloptions_function reloptsfun);
 extern void *build_reloptions(Datum reloptions, bool validate,
 							  relopt_kind kind,
 							  Size relopt_struct_size,
@@ -251,6 +253,8 @@ extern bytea *default_reloptions(Datum reloptions, bool validate,
 extern bytea *heap_reloptions(char relkind, Datum reloptions, bool validate);
 extern bytea *view_reloptions(Datum reloptions, bool validate);
 extern bytea *partitioned_table_reloptions(Datum reloptions, bool validate);
+extern bytea *table_reloptions(reloptions_function reloptsfun, Oid amid, char relkind,
+							   Datum reloptions, bool validate);
 extern bytea *index_reloptions(amoptions_function amoptions, Datum reloptions,
 							   bool validate);
 extern bytea *attribute_reloptions(Datum reloptions, bool validate);
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index 8713e12cbfb..b9544173f96 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -269,6 +269,14 @@ typedef void (*IndexBuildCallback) (Relation index,
 									bool tupleIsAlive,
 									void *state);
 
+/*
+ * Callback in charge of parsing and validating the table reloptions.
+ * It returns parsed options in bytea format.
+ */
+typedef bytea *(*reloptions_function) (char relkind,
+									   Datum reloptions,
+									   bool validate);
+
 /*
  * API struct for a table AM.  Note this must be allocated in a
  * server-lifetime manner, typically as a static const struct, which then gets
@@ -708,6 +716,8 @@ typedef struct TableAmRoutine
 	 * ------------------------------------------------------------------------
 	 */
 
+	reloptions_function relation_options;
+
 	/*
 	 * See table_relation_size().
 	 *
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index dd22b5efdfd..8e42f394107 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -136,6 +136,7 @@ extern ObjectAddress AlterUserMapping(AlterUserMappingStmt *stmt);
 extern Oid	RemoveUserMapping(DropUserMappingStmt *stmt);
 extern void CreateForeignTable(CreateForeignTableStmt *stmt, Oid relid);
 extern void ImportForeignSchema(ImportForeignSchemaStmt *stmt);
+extern Datum optionListToArray(List *options);
 extern Datum transformGenericOptions(Oid catalogId,
 									 Datum oldOptions,
 									 List *options,
-- 
2.39.5


--kp2yjslz3dxnr4ia
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v4-0002-Add-the-dummy_table_am-test-module.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v3 6/7] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the
optional pretty argument.
---
 src/backend/catalog/system_functions.sql |  7 +++++++
 src/backend/commands/tablecmds.c         |  4 ++--
 src/backend/utils/adt/ruleutils.c        | 17 -----------------
 src/include/catalog/pg_proc.dat          |  5 +----
 src/include/catalog/pg_retired.dat       |  3 ++-
 5 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 1824faab231..a6f7cdf3a36 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -692,6 +692,13 @@ LANGUAGE INTERNAL
 PARALLEL SAFE
 AS 'pg_get_constraintdef';
 
+CREATE OR REPLACE FUNCTION
+  pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false)
+RETURNS TEXT
+LANGUAGE INTERNAL
+PARALLEL SAFE
+AS 'pg_get_expr';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f976c0e5c7e..12c4ce08437 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid), false);
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 4f2c93f1ee2..d87b361a093 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index ffec11c5539..4304ab220ba 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3986,9 +3986,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8518,7 +8515,7 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
diff --git a/src/include/catalog/pg_retired.dat b/src/include/catalog/pg_retired.dat
index 90928a9cb00..8b5f58850f6 100644
--- a/src/include/catalog/pg_retired.dat
+++ b/src/include/catalog/pg_retired.dat
@@ -21,6 +21,7 @@
 { oid => '1573', proname => 'pg_get_ruledef' },
 { oid => '1640', proname => 'pg_get_viewdef' },
 { oid => '1641', proname => 'pg_get_viewdef' },
-{ oid => '1643', proname => 'pg_get_indexdef' }
+{ oid => '1643', proname => 'pg_get_indexdef' },
+{ oid => '1716', proname => 'pg_get_expr' }
 
 ]
-- 
2.43.0


--zd8Z8rlPOcTi77n/
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0007-Handle-pg_get_triggerdef-default-args-in-system_f.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v4 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  7 +++----
 3 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index b04b0dbd2a0..a523a512949 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17477,8 +17477,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 03550f0d80b..a70807e84ca 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2574,23 +2574,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 1d1b24a8f4c..69c1e5bb264 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3987,9 +3987,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8531,7 +8528,9 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.43.0


--eEEy3EHc57lA8spa
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v4-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v5 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  7 +++----
 3 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 0ce2e81f9c2..fad4202b1ff 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17694,8 +17694,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 1afa2531f30..972f89eafbc 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e148b1ad8e3..f36f4625e50 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4000,9 +4000,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8595,7 +8592,9 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.52.0


--m23X5uHFNxthGTU3
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v5-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v7 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  9 ++++-----
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index eec09ba1ded..73eb6322daf 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17695,8 +17695,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 2d39bce7fd7..707f83d4310 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 39139fd9e3b..855529509de 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4006,9 +4006,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8638,9 +8635,11 @@
   pronargdefaults => '1', proargdefaults => '{NULL}',
   prosrc => 'pg_get_database_ddl' },
 { oid => '2509',
-  descr => 'deparse an encoded expression with pretty-print option',
+  descr => 'deparse an encoded expression',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.52.0


--GzYugJnip6WHHvTk
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v7-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v8 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  9 ++++-----
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a1845240a98..f063f744f6d 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d83be8cf77d..e60478677e0 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 7e452aa8c27..71bd2aaf3d9 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4006,9 +4006,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8605,9 +8602,11 @@
   proargmodes => '{i,v}', proargdefaults => '{NULL}',
   prosrc => 'pg_get_database_ddl' },
 { oid => '2509',
-  descr => 'deparse an encoded expression with pretty-print option',
+  descr => 'deparse an encoded expression',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.53.0


--iWwo79nqhOvOs5kf
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v8-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v8.1 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  9 ++++-----
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a1845240a98..f063f744f6d 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d83be8cf77d..e60478677e0 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e610a6213ec..df43469be3d 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4006,9 +4006,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8605,9 +8602,11 @@
   proargmodes => '{i,v}', proargdefaults => '{NULL}',
   prosrc => 'pg_get_database_ddl' },
 { oid => '2509',
-  descr => 'deparse an encoded expression with pretty-print option',
+  descr => 'deparse an encoded expression',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.53.0


--AcCatzXgbvyipyEy
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v8.1-0006-Handle-pg_get_triggerdef-default-args-in-system.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v1 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the
optional pretty argument.
---
 src/backend/catalog/system_functions.sql |  7 +++++++
 src/backend/utils/adt/ruleutils.c        | 17 -----------------
 src/include/catalog/pg_proc.dat          |  5 +----
 3 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 1f89dcc7908..81d210a9c45 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -692,6 +692,13 @@ LANGUAGE INTERNAL
 PARALLEL SAFE
 AS 'pg_get_constraintdef';
 
+CREATE OR REPLACE FUNCTION
+  pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false)
+RETURNS TEXT
+LANGUAGE INTERNAL
+PARALLEL SAFE
+AS 'pg_get_expr';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 416144c49f5..9effa02fa2e 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index a9431ea4037..10c5286bd7d 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3977,9 +3977,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8502,7 +8499,7 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.51.2


--IRGsBYp1UN8d6WrT
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v1 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the
optional pretty argument.
---
 src/backend/catalog/system_functions.sql |  7 +++++++
 src/backend/utils/adt/ruleutils.c        | 17 -----------------
 src/include/catalog/pg_proc.dat          |  5 +----
 3 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 1f89dcc7908..81d210a9c45 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -692,6 +692,13 @@ LANGUAGE INTERNAL
 PARALLEL SAFE
 AS 'pg_get_constraintdef';
 
+CREATE OR REPLACE FUNCTION
+  pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false)
+RETURNS TEXT
+LANGUAGE INTERNAL
+PARALLEL SAFE
+AS 'pg_get_expr';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 416144c49f5..9effa02fa2e 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index a9431ea4037..10c5286bd7d 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3977,9 +3977,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8502,7 +8499,7 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.51.2


--IRGsBYp1UN8d6WrT
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v3 6/7] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the
optional pretty argument.
---
 src/backend/catalog/system_functions.sql |  7 +++++++
 src/backend/commands/tablecmds.c         |  4 ++--
 src/backend/utils/adt/ruleutils.c        | 17 -----------------
 src/include/catalog/pg_proc.dat          |  5 +----
 src/include/catalog/pg_retired.dat       |  3 ++-
 5 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 1824faab231..a6f7cdf3a36 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -692,6 +692,13 @@ LANGUAGE INTERNAL
 PARALLEL SAFE
 AS 'pg_get_constraintdef';
 
+CREATE OR REPLACE FUNCTION
+  pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false)
+RETURNS TEXT
+LANGUAGE INTERNAL
+PARALLEL SAFE
+AS 'pg_get_expr';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f976c0e5c7e..12c4ce08437 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid), false);
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 4f2c93f1ee2..d87b361a093 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index ffec11c5539..4304ab220ba 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3986,9 +3986,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8518,7 +8515,7 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
diff --git a/src/include/catalog/pg_retired.dat b/src/include/catalog/pg_retired.dat
index 90928a9cb00..8b5f58850f6 100644
--- a/src/include/catalog/pg_retired.dat
+++ b/src/include/catalog/pg_retired.dat
@@ -21,6 +21,7 @@
 { oid => '1573', proname => 'pg_get_ruledef' },
 { oid => '1640', proname => 'pg_get_viewdef' },
 { oid => '1641', proname => 'pg_get_viewdef' },
-{ oid => '1643', proname => 'pg_get_indexdef' }
+{ oid => '1643', proname => 'pg_get_indexdef' },
+{ oid => '1716', proname => 'pg_get_expr' }
 
 ]
-- 
2.43.0


--zd8Z8rlPOcTi77n/
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0007-Handle-pg_get_triggerdef-default-args-in-system_f.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v4 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  7 +++----
 3 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index b04b0dbd2a0..a523a512949 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17477,8 +17477,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 03550f0d80b..a70807e84ca 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2574,23 +2574,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 1d1b24a8f4c..69c1e5bb264 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3987,9 +3987,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8531,7 +8528,9 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.43.0


--eEEy3EHc57lA8spa
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v4-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v5 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  7 +++----
 3 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 0ce2e81f9c2..fad4202b1ff 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17694,8 +17694,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 1afa2531f30..972f89eafbc 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e148b1ad8e3..f36f4625e50 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4000,9 +4000,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8595,7 +8592,9 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.52.0


--m23X5uHFNxthGTU3
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v5-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v7 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  9 ++++-----
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index eec09ba1ded..73eb6322daf 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17695,8 +17695,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 2d39bce7fd7..707f83d4310 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 39139fd9e3b..855529509de 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4006,9 +4006,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8638,9 +8635,11 @@
   pronargdefaults => '1', proargdefaults => '{NULL}',
   prosrc => 'pg_get_database_ddl' },
 { oid => '2509',
-  descr => 'deparse an encoded expression with pretty-print option',
+  descr => 'deparse an encoded expression',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.52.0


--GzYugJnip6WHHvTk
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v7-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v8 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  9 ++++-----
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a1845240a98..f063f744f6d 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d83be8cf77d..e60478677e0 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 7e452aa8c27..71bd2aaf3d9 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4006,9 +4006,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8605,9 +8602,11 @@
   proargmodes => '{i,v}', proargdefaults => '{NULL}',
   prosrc => 'pg_get_database_ddl' },
 { oid => '2509',
-  descr => 'deparse an encoded expression with pretty-print option',
+  descr => 'deparse an encoded expression',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.53.0


--iWwo79nqhOvOs5kf
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v8-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v8.1 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use proargdefaults to handle the optional
pretty argument.  That also means any direct function calls now needs to
set the pretty parameter.
---
 src/backend/commands/tablecmds.c  |  5 +++--
 src/backend/utils/adt/ruleutils.c | 17 -----------------
 src/include/catalog/pg_proc.dat   |  9 ++++-----
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a1845240a98..f063f744f6d 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17730,8 +17730,9 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid),
+							   BoolGetDatum(false));
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d83be8cf77d..e60478677e0 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2932,23 +2932,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e610a6213ec..df43469be3d 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4006,9 +4006,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8605,9 +8602,11 @@
   proargmodes => '{i,v}', proargdefaults => '{NULL}',
   prosrc => 'pg_get_database_ddl' },
 { oid => '2509',
-  descr => 'deparse an encoded expression with pretty-print option',
+  descr => 'deparse an encoded expression',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool',
+  proargnames => '{expr,relation,pretty}', proargdefaults => '{false}',
+  prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.53.0


--AcCatzXgbvyipyEy
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v8.1-0006-Handle-pg_get_triggerdef-default-args-in-system.patch



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v2 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the
optional pretty argument.
---
 src/backend/catalog/system_functions.sql |  7 +++++++
 src/backend/commands/tablecmds.c         |  4 ++--
 src/backend/utils/adt/ruleutils.c        | 17 -----------------
 src/include/catalog/pg_proc.dat          |  5 +----
 4 files changed, 10 insertions(+), 23 deletions(-)

diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 1824faab231..a6f7cdf3a36 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -692,6 +692,13 @@ LANGUAGE INTERNAL
 PARALLEL SAFE
 AS 'pg_get_constraintdef';
 
+CREATE OR REPLACE FUNCTION
+  pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false)
+RETURNS TEXT
+LANGUAGE INTERNAL
+PARALLEL SAFE
+AS 'pg_get_expr';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f976c0e5c7e..12c4ce08437 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid), false);
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9faf340f0c6..305e3e80c41 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 96eb7baf8e0..3a0be2d4b2a 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3986,9 +3986,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8518,7 +8515,7 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.43.0


--3/nz5wg6+DYwHsLU
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v2-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH v2 5/6] Handle pg_get_expr default args in system_functions.sql
@ 2025-12-09 19:17  Mark Wong <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Mark Wong @ 2025-12-09 19:17 UTC (permalink / raw)

Modernize pg_get_expr to use CREATE OR REPLACE FUNCTION to handle the
optional pretty argument.
---
 src/backend/catalog/system_functions.sql |  7 +++++++
 src/backend/commands/tablecmds.c         |  4 ++--
 src/backend/utils/adt/ruleutils.c        | 17 -----------------
 src/include/catalog/pg_proc.dat          |  5 +----
 4 files changed, 10 insertions(+), 23 deletions(-)

diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 1824faab231..a6f7cdf3a36 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -692,6 +692,13 @@ LANGUAGE INTERNAL
 PARALLEL SAFE
 AS 'pg_get_constraintdef';
 
+CREATE OR REPLACE FUNCTION
+  pg_get_expr(expr pg_node_tree, relation oid, pretty bool DEFAULT false)
+RETURNS TEXT
+LANGUAGE INTERNAL
+PARALLEL SAFE
+AS 'pg_get_expr';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f976c0e5c7e..12c4ce08437 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17480,8 +17480,8 @@ decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
 	if (isnull)
 		elog(ERROR, "null conbin for constraint %u", con->oid);
 
-	expr = DirectFunctionCall2(pg_get_expr, attr,
-							   ObjectIdGetDatum(con->conrelid));
+	expr = DirectFunctionCall3(pg_get_expr, attr,
+							   ObjectIdGetDatum(con->conrelid), false);
 	return TextDatumGetCString(expr);
 }
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9faf340f0c6..305e3e80c41 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2573,23 +2573,6 @@ decompile_column_index_array(Datum column_index_array, Oid relId,
  */
 Datum
 pg_get_expr(PG_FUNCTION_ARGS)
-{
-	text	   *expr = PG_GETARG_TEXT_PP(0);
-	Oid			relid = PG_GETARG_OID(1);
-	text	   *result;
-	int			prettyFlags;
-
-	prettyFlags = PRETTYFLAG_INDENT;
-
-	result = pg_get_expr_worker(expr, relid, prettyFlags);
-	if (result)
-		PG_RETURN_TEXT_P(result);
-	else
-		PG_RETURN_NULL();
-}
-
-Datum
-pg_get_expr_ext(PG_FUNCTION_ARGS)
 {
 	text	   *expr = PG_GETARG_TEXT_PP(0);
 	Oid			relid = PG_GETARG_OID(1);
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 96eb7baf8e0..3a0be2d4b2a 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3986,9 +3986,6 @@
 { oid => '1662', descr => 'trigger description',
   proname => 'pg_get_triggerdef', provolatile => 's', prorettype => 'text',
   proargtypes => 'oid', prosrc => 'pg_get_triggerdef' },
-{ oid => '1716', descr => 'deparse an encoded expression',
-  proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid', prosrc => 'pg_get_expr' },
 { oid => '1665', descr => 'name of sequence for a serial column',
   proname => 'pg_get_serial_sequence', provolatile => 's', prorettype => 'text',
   proargtypes => 'text text', prosrc => 'pg_get_serial_sequence' },
@@ -8518,7 +8515,7 @@
 { oid => '2509',
   descr => 'deparse an encoded expression with pretty-print option',
   proname => 'pg_get_expr', provolatile => 's', prorettype => 'text',
-  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr_ext' },
+  proargtypes => 'pg_node_tree oid bool', prosrc => 'pg_get_expr' },
 { oid => '2510', descr => 'get the prepared statements for this session',
   proname => 'pg_prepared_statement', prorows => '1000', proretset => 't',
   provolatile => 's', proparallel => 'r', prorettype => 'record',
-- 
2.43.0


--3/nz5wg6+DYwHsLU
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v2-0006-Handle-pg_get_triggerdef-default-args-in-system_f.patch"



^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 333+ messages in thread

* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 333+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





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