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 <[email protected]> Co-authored-by: Alexander Korotkov <[email protected]> Co-authored-by: Tender Wang <[email protected]> Co-authored-by: Richard Guo <[email protected]> Co-authored-by: Dagfinn Ilmari Mannsaker <[email protected]> Co-authored-by: Fujii Masao <[email protected]> Co-authored-by: Jian He <[email protected]> Reviewed-by: Matthias van de Meent <[email protected]> Reviewed-by: Laurenz Albe <[email protected]> Reviewed-by: Zhihong Yu <[email protected]> Reviewed-by: Justin Pryzby <[email protected]> Reviewed-by: Alvaro Herrera <[email protected]> Reviewed-by: Robert Haas <[email protected]> Reviewed-by: Stephane Tachoires <[email protected]> Reviewed-by: Jian He <[email protected]> Reviewed-by: Alexander Korotkov <[email protected]> Reviewed-by: Pavel Borisov <[email protected]> Reviewed-by: Masahiko Sawada <[email protected]> Reviewed-by: Alexander Lakhin <[email protected]> Reviewed-by: Kyotaro Horiguchi <[email protected]> Reviewed-by: Daniel Gustafsson <[email protected]> Reviewed-by: Tom Lane <[email protected]> Reviewed-by: Noah Misch <[email protected]> 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(-)
