Mention pg_index changes also cause relcache invalidation

simonat2ndQuadrant · simonat2ndQuadrant · commit 2c2ecddcffba · 2017-04-13T10:07:21.000+01:00
Amit Langote, additional line by me
diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
@@ -51,9 +51,9 @@
  *	PrepareToInvalidateCacheTuple() routine provides the knowledge of which
  *	catcaches may need invalidation for a given tuple.
  *
- *	Also, whenever we see an operation on a pg_class or pg_attribute tuple,
- *	we register a relcache flush operation for the relation described by that
- *	tuple.
+ *	Also, whenever we see an operation on a pg_class, pg_attribute, or
+ *	pg_index tuple, we register a relcache flush operation for the relation
+ *	described by that tuple (as specified in CacheInvalidateHeapTuple()).
  *
  *	We keep the relcache flush requests in lists separate from the catcache
  *	tuple flush requests.  This allows us to issue all the pending catcache
@@ -1132,6 +1132,7 @@ CacheInvalidateHeapTuple(Relation relation,
 
 	/*
 	 * Now, is this tuple one of the primary definers of a relcache entry?
+	 * See comments in file header for deeper explanation.
 	 *
 	 * Note we ignore newtuple here; we assume an update cannot move a tuple
 	 * from being part of one relcache entry to being part of another.

Original file line number	Diff line number	Diff line change
`@@ -51,9 +51,9 @@`
`51`	`51`	`* PrepareToInvalidateCacheTuple() routine provides the knowledge of which`
`52`	`52`	`* catcaches may need invalidation for a given tuple.`
`53`	`53`	`*`
`54`		`- * Also, whenever we see an operation on a pg_class or pg_attribute tuple,`
`55`		`- * we register a relcache flush operation for the relation described by that`
`56`		`- * tuple.`
	`54`	`+ * Also, whenever we see an operation on a pg_class, pg_attribute, or`
	`55`	`+ * pg_index tuple, we register a relcache flush operation for the relation`
	`56`	`+ * described by that tuple (as specified in CacheInvalidateHeapTuple()).`
`57`	`57`	`*`
`58`	`58`	`* We keep the relcache flush requests in lists separate from the catcache`
`59`	`59`	`* tuple flush requests. This allows us to issue all the pending catcache`
`@@ -1132,6 +1132,7 @@ CacheInvalidateHeapTuple(Relation relation,`
`1132`	`1132`
`1133`	`1133`	`/*`
`1134`	`1134`	`* Now, is this tuple one of the primary definers of a relcache entry?`
	`1135`	`+ * See comments in file header for deeper explanation.`
`1135`	`1136`	`*`
`1136`	`1137`	`* Note we ignore newtuple here; we assume an update cannot move a tuple`
`1137`	`1138`	`* from being part of one relcache entry to being part of another.`