Introduce wal_level GUC to explicitly control if information needed for

archival or hot standby should be WAL-logged, instead of deducing that from
other options like archive_mode. This replaces recovery_connections GUC in
the primary, where it now has no effect, but it's still used in the standby
to enable/disable hot standby.

Remove the WAL-logging of "unlogged operations", like creating an index
without WAL-logging and fsyncing it at the end. Instead, we keep a copy of
the wal_mode setting and the settings that affect how much shared memory a
hot standby server needs to track master transactions (max_connections,
max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings
change, at server restart, write a WAL record noting the new settings and
update pg_control. This allows us to notice the change in those settings in
the standby at the right moment, they used to be included in checkpoint
records, but that meant that a changed value was not reflected in the
standby until the first checkpoint after the change.

Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to
the sequence it used to follow, before hot standby and subsequent patches
changed it to 0x9003.

1 files changed, 1 insertions, 26 deletions

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index dda0b2e847e..18e2f571283 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.329 2010/03/20 00:43:42 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.330 2010/04/28 16:10:41 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3272,14 +3272,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap)
 
 		/* If we skipped writing WAL, then we need to sync the heap. */
 		if (hi_options & HEAP_INSERT_SKIP_WAL)
-		{
-			char		reason[NAMEDATALEN + 30];
-
-			snprintf(reason, sizeof(reason), "table rewrite on \"%s\"",
-					 RelationGetRelationName(newrel));
-			XLogReportUnloggedStatement(reason);
 			heap_sync(newrel);
-		}
 
 		heap_close(newrel, NoLock);
 	}
@@ -7021,20 +7014,6 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace)
 
 	heap_close(pg_class, RowExclusiveLock);
 
-	/*
-	 * Write an XLOG UNLOGGED record if WAL-logging was skipped because WAL
-	 * archiving is not enabled.
-	 */
-	if (!XLogIsNeeded() && !rel->rd_istemp)
-	{
-		char		reason[NAMEDATALEN + 40];
-
-		snprintf(reason, sizeof(reason), "ALTER TABLE SET TABLESPACE on \"%s\"",
-				 RelationGetRelationName(rel));
-
-		XLogReportUnloggedStatement(reason);
-	}
-
 	relation_close(rel, NoLock);
 
 	/* Make sure the reltablespace change is visible */
@@ -7063,10 +7042,6 @@ copy_relation_data(SMgrRelation src, SMgrRelation dst,
 	/*
 	 * We need to log the copied data in WAL iff WAL archiving/streaming is
 	 * enabled AND it's not a temp rel.
-	 *
-	 * Note: If you change the conditions here, update the conditions in
-	 * ATExecSetTableSpace() for when an XLOG UNLOGGED record is written to
-	 * match.
 	 */
 	use_wal = XLogIsNeeded() && !istemp;