From 25303678a1d334200c0f1446eef2ebe1aaf2709b Mon Sep 17 00:00:00 2001 From: Dean Rasheed Date: Sat, 29 Mar 2025 09:50:14 +0000 Subject: [PATCH] Fix MERGE with DO NOTHING actions into a partitioned table. ExecInitPartitionInfo() duplicates much of the logic in ExecInitMerge(), except that it failed to handle DO NOTHING actions. This would cause an "unknown action in MERGE WHEN clause" error if a MERGE with any DO NOTHING actions attempted to insert into a partition not already initialised by ExecInitModifyTable(). Bug: #18871 Reported-by: Alexander Lakhin Author: Tender Wang Reviewed-by: Gurjeet Singh Discussion: https://postgr.es/m/18871-b44e3c96de3bd2e8%40postgresql.org Backpatch-through: 15 --- src/backend/executor/execPartition.c | 4 +++- src/backend/executor/nodeModifyTable.c | 2 +- src/test/regress/expected/merge.out | 17 +++++++++++++++++ src/test/regress/sql/merge.sql | 13 +++++++++++++ 4 files changed, 34 insertions(+), 2 deletions(-) diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c index 76518862291..a3602b81687 100644 --- a/src/backend/executor/execPartition.c +++ b/src/backend/executor/execPartition.c @@ -872,7 +872,7 @@ ExecInitPartitionInfo(ModifyTableState *mtstate, EState *estate, * reference and make copy for this relation, converting stuff that * references attribute numbers to match this relation's. * - * This duplicates much of the logic in ExecInitMerge(), so something + * This duplicates much of the logic in ExecInitMerge(), so if something * changes there, look here too. */ if (node && node->operation == CMD_MERGE) @@ -952,6 +952,8 @@ ExecInitPartitionInfo(ModifyTableState *mtstate, EState *estate, NULL); break; case CMD_DELETE: + case CMD_NOTHING: + /* Nothing to do */ break; default: diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c index 02be41845ac..d84e6dba45a 100644 --- a/src/backend/executor/nodeModifyTable.c +++ b/src/backend/executor/nodeModifyTable.c @@ -3600,7 +3600,7 @@ ExecInitMerge(ModifyTableState *mtstate, EState *estate) case CMD_NOTHING: break; default: - elog(ERROR, "unknown operation"); + elog(ERROR, "unknown action in MERGE WHEN clause"); break; } } diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out index 521d70a8919..e9c9b15d3c8 100644 --- a/src/test/regress/expected/merge.out +++ b/src/test/regress/expected/merge.out @@ -2058,6 +2058,23 @@ SELECT * FROM pa_target ORDER BY tid; 15 | 1500 | initial (8 rows) +ROLLBACK; +-- bug #18871: ExecInitPartitionInfo()'s handling of DO NOTHING actions +BEGIN; +TRUNCATE pa_target; +MERGE INTO pa_target t + USING (VALUES (10, 100)) AS s(sid, delta) + ON t.tid = s.sid + WHEN NOT MATCHED THEN + INSERT VALUES (1, 10, 'inserted by merge') + WHEN MATCHED THEN + DO NOTHING; +SELECT * FROM pa_target ORDER BY tid, val; + tid | balance | val +-----+---------+------------------- + 1 | 10 | inserted by merge +(1 row) + ROLLBACK; DROP TABLE pa_target CASCADE; -- The target table is partitioned in the same way, but this time by attaching diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql index 5ddcca84f82..556777e4f4b 100644 --- a/src/test/regress/sql/merge.sql +++ b/src/test/regress/sql/merge.sql @@ -1269,6 +1269,19 @@ MERGE INTO pa_target t SELECT * FROM pa_target ORDER BY tid; ROLLBACK; +-- bug #18871: ExecInitPartitionInfo()'s handling of DO NOTHING actions +BEGIN; +TRUNCATE pa_target; +MERGE INTO pa_target t + USING (VALUES (10, 100)) AS s(sid, delta) + ON t.tid = s.sid + WHEN NOT MATCHED THEN + INSERT VALUES (1, 10, 'inserted by merge') + WHEN MATCHED THEN + DO NOTHING; +SELECT * FROM pa_target ORDER BY tid, val; +ROLLBACK; + DROP TABLE pa_target CASCADE; -- The target table is partitioned in the same way, but this time by attaching