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(-)
