Initialize index stats during parallel VACUUM.

petergeoghegan · petergeoghegan · commit 662ba729a67e · 2022-08-18T17:34:14.000-07:00
Initialize shared memory allocated for index stats to avoid a hard crash. This was possible when parallel VACUUM became confused about the current phase of index processing. Oversight in commit 8e1fae1, which refactored parallel VACUUM. Author: Masahiko Sawada <sawada.mshk@gmail.com> Reported-By: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20220818133406.GL26426@telsasoft.com Backpatch: 15-, the first version with the refactoring commit.
diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
@@ -317,6 +317,7 @@ parallel_vacuum_init(Relation rel, Relation *indrels, int nindexes,
 
 	/* Prepare index vacuum stats */
 	indstats = (PVIndStats *) shm_toc_allocate(pcxt->toc, est_indstats_len);
+	MemSet(indstats, 0, est_indstats_len);
 	for (int i = 0; i < nindexes; i++)
 	{
 		Relation	indrel = indrels[i];

Original file line number	Diff line number	Diff line change
`@@ -317,6 +317,7 @@ parallel_vacuum_init(Relation rel, Relation *indrels, int nindexes,`
`317`	`317`
`318`	`318`	`/* Prepare index vacuum stats */`
`319`	`319`	`indstats = (PVIndStats *) shm_toc_allocate(pcxt->toc, est_indstats_len);`
	`320`	`+ MemSet(indstats, 0, est_indstats_len);`
`320`	`321`	`for (int i = 0; i < nindexes; i++)`
`321`	`322`	`{`
`322`	`323`	`Relation indrel = indrels[i];`