Support unlogged tables.

The contents of an unlogged table are WAL-logged; thus, they are not
available on standby servers and are truncated whenever the database
system enters recovery.  Indexes on unlogged tables are also unlogged.
Unlogged GiST indexes are not currently supported.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index bf62138bf86..1ec6f2f15ac 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -49,6 +49,7 @@
 #include "storage/latch.h"
 #include "storage/pmsignal.h"
 #include "storage/procarray.h"
+#include "storage/reinit.h"
 #include "storage/smgr.h"
 #include "storage/spin.h"
 #include "utils/builtins.h"
@@ -5961,6 +5962,14 @@ StartupXLOG(void)
 		CheckRequiredParameterValues();
 
 		/*
+		 * We're in recovery, so unlogged relations relations may be trashed
+		 * and must be reset.  This should be done BEFORE allowing Hot
+		 * Standby connections, so that read-only backends don't try to
+		 * read whatever garbage is left over from before.
+		 */
+		ResetUnloggedRelations(UNLOGGED_RELATION_CLEANUP);
+
+		/*
 		 * Initialize for Hot Standby, if enabled. We won't let backends in
 		 * yet, not until we've reached the min recovery point specified in
 		 * control file and we've established a recovery snapshot from a
@@ -6414,6 +6423,14 @@ StartupXLOG(void)
 	PreallocXlogFiles(EndOfLog);
 
 	/*
+	 * Reset initial contents of unlogged relations.  This has to be done
+	 * AFTER recovery is complete so that any unlogged relations created
+	 * during recovery also get picked up.
+	 */
+	if (InRecovery)
+		ResetUnloggedRelations(UNLOGGED_RELATION_INIT);
+
+	/*
 	 * Okay, we're officially UP.
 	 */
 	InRecovery = false;