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pgsql: Implement ALTER TABLE ... MERGE PARTITIONS ... command 2+ messages / 1 participants [nested] [flat]
* pgsql: Implement ALTER TABLE ... MERGE PARTITIONS ... command @ 2024-04-06 22:19 Alexander Korotkov <akorotkov@postgresql.org> 0 siblings, 0 replies; 2+ messages in thread From: Alexander Korotkov @ 2024-04-06 22:19 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Implement ALTER TABLE ... MERGE PARTITIONS ... command This new DDL command merges several partitions into the one partition of the target table. The target partition is created using new createPartitionTable() function with parent partition as the template. This commit comprises quite naive implementation which works in single process and holds the ACCESS EXCLUSIVE LOCK on the parent table during all the operations including the tuple routing. This is why this new DDL command can't be recommended for large partitioned tables under a high load. However, this implementation come in handy in certain cases even as is. Also, it could be used as a foundation for future implementations with lesser locking and possibly parallel. Discussion: https://postgr.es/m/c73a1746-0cd0-6bdd-6b23-3ae0b7c0c582%40postgrespro.ru Author: Dmitry Koval Reviewed-by: Matthias van de Meent, Laurenz Albe, Zhihong Yu, Justin Pryzby Reviewed-by: Alvaro Herrera, Robert Haas, Stephane Tachoires Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/1adf16b8fba45f77056d91573cd7138ed9da4ebf Modified Files -------------- doc/src/sgml/ddl.sgml | 19 + doc/src/sgml/ref/alter_table.sgml | 77 ++- src/backend/commands/tablecmds.c | 354 +++++++++- src/backend/parser/gram.y | 22 +- src/backend/parser/parse_utilcmd.c | 89 +++ src/backend/partitioning/partbounds.c | 207 ++++++ src/include/nodes/parsenodes.h | 14 + src/include/parser/kwlist.h | 1 + src/include/partitioning/partbounds.h | 6 + src/test/isolation/expected/partition-merge.out | 199 ++++++ src/test/isolation/isolation_schedule | 1 + src/test/isolation/specs/partition-merge.spec | 54 ++ .../modules/test_ddl_deparse/test_ddl_deparse.c | 3 + src/test/regress/expected/partition_merge.out | 732 +++++++++++++++++++++ src/test/regress/parallel_schedule | 2 +- src/test/regress/sql/partition_merge.sql | 430 ++++++++++++ src/tools/pgindent/typedefs.list | 1 + 17 files changed, 2189 insertions(+), 22 deletions(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
* pgsql: Implement ALTER TABLE ... MERGE PARTITIONS ... command @ 2025-12-14 11:30 Alexander Korotkov <akorotkov@postgresql.org> 0 siblings, 0 replies; 2+ messages in thread From: Alexander Korotkov @ 2025-12-14 11:30 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Implement ALTER TABLE ... MERGE PARTITIONS ... command This new DDL command merges several partitions into a single partition of the target table. The target partition is created using the new createPartitionTable() function with the parent partition as the template. This commit comprises a quite naive implementation which works in a single process and holds the ACCESS EXCLUSIVE LOCK on the parent table during all the operations, including the tuple routing. This is why this new DDL command can't be recommended for large partitioned tables under a high load. However, this implementation comes in handy in certain cases, even as it is. Also, it could serve as a foundation for future implementations with less locking and possibly parallelism. Discussion: https://postgr.es/m/c73a1746-0cd0-6bdd-6b23-3ae0b7c0c582%40postgrespro.ru Author: Dmitry Koval <d.koval@postgrespro.ru> Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com> Co-authored-by: Tender Wang <tndrwang@gmail.com> Co-authored-by: Richard Guo <guofenglinux@gmail.com> Co-authored-by: Dagfinn Ilmari Mannsaker <ilmari@ilmari.org> Co-authored-by: Fujii Masao <masao.fujii@gmail.com> Co-authored-by: Jian He <jian.universality@gmail.com> Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com> Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at> Reviewed-by: Zhihong Yu <zyu@yugabyte.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Robert Haas <rhaas@postgresql.org> Reviewed-by: Stephane Tachoires <stephane.tachoires@gmail.com> Reviewed-by: Jian He <jian.universality@gmail.com> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-by: Alexander Lakhin <exclusion@gmail.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Daniel Gustafsson <dgustafsson@postgresql.org> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Noah Misch <noah@leadboat.com> Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/f2e4cc427951b7c46629fb7625a22f7898586f3a Modified Files -------------- doc/src/sgml/ddl.sgml | 19 + doc/src/sgml/ref/alter_table.sgml | 127 ++- src/backend/catalog/dependency.c | 54 +- src/backend/catalog/pg_constraint.c | 2 +- src/backend/commands/tablecmds.c | 894 +++++++++++++++- src/backend/parser/gram.y | 22 +- src/backend/parser/parse_utilcmd.c | 152 ++- src/backend/partitioning/partbounds.c | 196 ++++ src/bin/psql/tab-complete.in.c | 10 + src/include/catalog/dependency.h | 2 + src/include/nodes/parsenodes.h | 8 +- src/include/parser/kwlist.h | 1 + src/include/partitioning/partbounds.h | 6 + src/test/isolation/expected/partition-merge.out | 243 +++++ src/test/isolation/isolation_schedule | 1 + src/test/isolation/specs/partition-merge.spec | 62 ++ .../test_ddl_deparse/expected/alter_table.out | 5 + .../modules/test_ddl_deparse/sql/alter_table.sql | 3 + .../modules/test_ddl_deparse/test_ddl_deparse.c | 3 + src/test/regress/expected/partition_merge.out | 1097 ++++++++++++++++++++ src/test/regress/parallel_schedule | 2 +- src/test/regress/sql/partition_merge.sql | 791 ++++++++++++++ 22 files changed, 3668 insertions(+), 32 deletions(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2025-12-14 11:30 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2024-04-06 22:19 pgsql: Implement ALTER TABLE ... MERGE PARTITIONS ... command Alexander Korotkov <akorotkov@postgresql.org> 2025-12-14 11:30 pgsql: Implement ALTER TABLE ... MERGE PARTITIONS ... command Alexander Korotkov <akorotkov@postgresql.org>
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