Fix potential catalog corruption with temporary identity columns

petere · petere · commit 10b2675d6e79 · 2019-04-29T08:49:22.000+02:00
If a temporary table with an identity column and ON COMMIT DROP is
created in a single-statement transaction (not useful, but allowed),
it would leave the catalog corrupted.  We need to add a
CommandCounterIncrement() so that PreCommit_on_commit_actions() sees
the created dependency between table and sequence and can clean it
up.

The analogous and more useful case of doing this in a transaction
block already runs some CommandCounterIncrement() before it gets to
the on-commit cleanup, so it wasn't a problem in practical use.

Several locations for placing the new CommandCounterIncrement() call
were discussed.  This patch places it at the end of
standard_ProcessUtility().  That would also help if other commands
were to create catalog entries that some on-commit action would like
to see.

Bug: #15631
Reported-by: Serge Latyntsev &lt;dnsl48@gmail.com&gt;
Author: Peter Eisentraut &lt;peter.eisentraut@2ndquadrant.com&gt;
Reviewed-by: Michael Paquier &lt;michael@paquier.xyz&gt;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
@@ -935,6 +935,13 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 	}
 
 	free_parsestate(pstate);
+
+	/*
+	 * Make effects of commands visible, for instance so that
+	 * PreCommit_on_commit_actions() can see them (see for example bug
+	 * #15631).
+	 */
+	CommandCounterIncrement();
 }
 
 /*

Original file line number	Diff line number	Diff line change
`@@ -935,6 +935,13 @@ standard_ProcessUtility(PlannedStmt *pstmt,`
`935`	`935`	`}`
`936`	`936`
`937`	`937`	`free_parsestate(pstate);`
	`938`	`+`
	`939`	`+ /*`
	`940`	`+ * Make effects of commands visible, for instance so that`
	`941`	`+ * PreCommit_on_commit_actions() can see them (see for example bug`
	`942`	`+ * #15631).`
	`943`	`+ */`
	`944`	`+ CommandCounterIncrement();`
`938`	`945`	`}`
`939`	`946`
`940`	`947`	`/*`