From 5cab276a9b91848341bb96ab96c170cecd65f0bd Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Wed, 13 Jun 2012 15:49:15 -0400
Subject: [PATCH] Rejigger metadata creation.

---
 src/backend/access/common/metapage.c | 27 +++++++++++++++++++++++++--
 src/backend/utils/cache/relcache.c   |  5 +++++
 src/include/access/metapage.h        |  1 +
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/backend/access/common/metapage.c b/src/backend/access/common/metapage.c
index b143c55e77..f311eb91e1 100644
--- a/src/backend/access/common/metapage.c
+++ b/src/backend/access/common/metapage.c
@@ -38,9 +38,29 @@ MetapageInit(Relation relation, Page page)
 {
 	RelationMetapage	meta;
 
+	if (relation->rd_metapage == NULL)
+		RelationBuildMetadata(relation);
 	PageSetRelationMetapage(page);
-
 	meta = BlindGetRelationMeta(page);
+	memcpy(meta, relation->rd_metapage, sizeof(RelationMetapageData));
+}
+
+/*
+ * Build metadata for a new relation.
+ */
+void
+RelationBuildMetadata(Relation relation)
+{
+	RelationMetapage	meta;
+
+	/* The metadata shouldn't already be initialized. */
+	Assert(relation->rd_metapage == NULL);
+
+	/* Allocate memory for the data. */
+	meta = (RelationMetapage) MemoryContextAllocZero(CacheMemoryContext,
+		sizeof(RelationMetapageData));
+
+	/* Initialize. */
 	meta->rmp_magic = METAPAGE_MAGIC;
 	meta->rmp_version = METAPAGE_VERSION;
 	meta->rmp_dboid = relation->rd_node.dbNode;
@@ -51,6 +71,9 @@ MetapageInit(Relation relation, Page page)
 	meta->rmp_minlayout = PG_PAGE_LAYOUT_VERSION;
 	meta->rmp_maxlayout = PG_PAGE_LAYOUT_VERSION;
 	meta->rmp_relfilenode_time = (pg_time_t) time(NULL);
+
+	/* Save it. */
+	relation->rd_metapage = meta;
 }
 
 /*
@@ -75,7 +98,7 @@ RelationGetMetadata(Relation relation)
 	 * If the relation has a metapage, read it.
 	 *
 	 * XXX: It's pretty annoying to have to call RelationGetNumberOfBlocks.
-	 * Can't we have an RBM_ERROR option for ReadBufferExtended?
+	 * Can't we have an RBM_FAIL option for ReadBufferExtended?
 	 */
 	if (RelationGetNumberOfBlocks(relation) > METAPAGE_BLKNO)
 	{
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 65e4372b11..685955e58b 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -30,6 +30,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include "access/metapage.h"
 #include "access/reloptions.h"
 #include "access/sysattr.h"
 #include "access/transam.h"
@@ -2587,6 +2588,10 @@ RelationBuildLocalRelation(const char *relname,
 
 	RelationInitPhysicalAddr(rel);
 
+	/* XXX: Not for heaps yet. */
+	if (relkind == RELKIND_INDEX)
+		RelationBuildMetadata(rel);
+
 	/*
 	 * Okay to insert into the relcache hash tables.
 	 */
diff --git a/src/include/access/metapage.h b/src/include/access/metapage.h
index 65c68bdabd..a119dc4dc6 100644
--- a/src/include/access/metapage.h
+++ b/src/include/access/metapage.h
@@ -72,6 +72,7 @@ typedef RelationMetapageData *RelationMetapage;
  * Function prototypes.
  */
 extern void MetapageInit(Relation relation, Page page);
+extern void RelationBuildMetadata(Relation relation);
 extern RelationMetapage RelationGetMetadata(Relation rel);
 
 /*
-- 
2.39.5