WAL-log the creation of the init fork of unlogged indexes.

hlinnaka · hlinnaka · commit 3142a8845b44 · 2023-07-06T17:25:29.000+03:00
We create a file, so we better WAL-log it. In practice, all the built-in index AMs and all extensions that I'm aware of write a metapage to the init fork, which is WAL-logged, and replay of the metapage implicitly creates the fork too. But if ambuildempty() didn't write any page, we would miss it. This can be seen with dummy_index_am. Set up replication, create a 'dummy_index_am' index on an unlogged table, and look at the files created in the replica: the init fork is not created on the replica. Dummy_index_am doesn't do anything with the relation files, however, so it doesn't lead to any user-visible errors. Backpatch to all supported versions. Reviewed-by: Robert Haas Discussion: https://www.postgresql.org/message-id/6e5bbc08-cdfc-b2b3-9e23-1a914b9850a9%40iki.fi
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
@@ -54,6 +54,7 @@
 #include "catalog/pg_trigger.h"
 #include "catalog/pg_type.h"
 #include "catalog/storage.h"
+#include "catalog/storage_xlog.h"
 #include "commands/event_trigger.h"
 #include "commands/progress.h"
 #include "commands/tablecmds.h"
@@ -3044,6 +3045,7 @@ index_build(Relation heapRelation,
 		!smgrexists(RelationGetSmgr(indexRelation), INIT_FORKNUM))
 	{
 		smgrcreate(RelationGetSmgr(indexRelation), INIT_FORKNUM, false);
+		log_smgrcreate(&indexRelation->rd_locator, INIT_FORKNUM);
 		indexRelation->rd_indam->ambuildempty(indexRelation);
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -54,6 +54,7 @@`
`54`	`54`	`#include "catalog/pg_trigger.h"`
`55`	`55`	`#include "catalog/pg_type.h"`
`56`	`56`	`#include "catalog/storage.h"`
	`57`	`+#include "catalog/storage_xlog.h"`
`57`	`58`	`#include "commands/event_trigger.h"`
`58`	`59`	`#include "commands/progress.h"`
`59`	`60`	`#include "commands/tablecmds.h"`
`@@ -3044,6 +3045,7 @@ index_build(Relation heapRelation,`
`3044`	`3045`	`!smgrexists(RelationGetSmgr(indexRelation), INIT_FORKNUM))`
`3045`	`3046`	`{`
`3046`	`3047`	`smgrcreate(RelationGetSmgr(indexRelation), INIT_FORKNUM, false);`
	`3048`	`+ log_smgrcreate(&indexRelation->rd_locator, INIT_FORKNUM);`
`3047`	`3049`	`indexRelation->rd_indam->ambuildempty(indexRelation);`
`3048`	`3050`	`}`
`3049`	`3051`