Improve our #include situation by moving pointer types away from the

corresponding struct definitions.  This allows other headers to avoid including
certain highly-loaded headers such as rel.h and relscan.h, instead using just
relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less
unnecessary dependencies.

src/include/access/genam.h

@@ -7,19 +7,20 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/genam.h,v 1.73 2008/06/08 22:41:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/genam.h,v 1.74 2008/06/19 00:46:05 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef GENAM_H
 #define GENAM_H
 
-#include "access/relscan.h"
 #include "access/sdir.h"
+#include "access/skey.h"
 #include "nodes/tidbitmap.h"
 #include "storage/buf.h"
 #include "storage/lock.h"
-#include "utils/rel.h"
+#include "utils/relcache.h"
+#include "utils/snapshot.h"
 
 /*
  * Struct for statistics returned by ambuild
@@ -73,21 +74,21 @@ typedef struct IndexBulkDeleteResult
 /* Typedef for callback function to determine if a tuple is bulk-deletable */
 typedef bool (*IndexBulkDeleteCallback) (ItemPointer itemptr, void *state);
 
-/* Struct for heap-or-index scans of system tables */
-typedef struct SysScanDescData
-{
-	Relation	heap_rel;		/* catalog being scanned */
-	Relation	irel;			/* NULL if doing heap scan */
-	HeapScanDesc scan;			/* only valid in heap-scan case */
-	IndexScanDesc iscan;		/* only valid in index-scan case */
-} SysScanDescData;
-
-typedef SysScanDescData *SysScanDesc;
+/* struct definitions appear in relscan.h */
+typedef struct IndexScanDescData *IndexScanDesc;
+typedef struct SysScanDescData *SysScanDesc;
 
 
 /*
  * generalized index_ interface routines (in indexam.c)
  */
+
+/*
+ * IndexScanIsValid
+ *		True iff the index scan is valid.
+ */
+#define IndexScanIsValid(scan) PointerIsValid(scan)
+
 extern Relation index_open(Oid relationId, LOCKMODE lockmode);
 extern void index_close(Relation relation, LOCKMODE lockmode);
 

src/include/access/gin.h

@@ -4,7 +4,7 @@
  *
  *	Copyright (c) 2006-2008, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/include/access/gin.h,v 1.21 2008/06/06 22:35:22 alvherre Exp $
+ *	$PostgreSQL: pgsql/src/include/access/gin.h,v 1.22 2008/06/19 00:46:05 alvherre Exp $
  *--------------------------------------------------------------------------
  */
 
@@ -12,8 +12,8 @@
 #ifndef GIN_H
 #define GIN_H
 
+#include "access/genam.h"
 #include "access/itup.h"
-#include "access/relscan.h"
 #include "access/xlog.h"
 #include "fmgr.h"
 #include "nodes/tidbitmap.h"

src/include/access/gist.h

@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/gist.h,v 1.60 2008/05/12 00:00:53 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/access/gist.h,v 1.61 2008/06/19 00:46:05 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,8 +18,9 @@
 
 #include "access/xlog.h"
 #include "access/xlogdefs.h"
+#include "storage/block.h"
 #include "storage/bufpage.h"
-#include "utils/rel.h"
+#include "utils/relcache.h"
 
 /*
  * amproc indexes for GiST indexes.

src/include/access/gist_private.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/gist_private.h,v 1.30 2008/06/12 09:12:31 heikki Exp $
+ * $PostgreSQL: pgsql/src/include/access/gist_private.h,v 1.31 2008/06/19 00:46:05 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,9 +16,7 @@
 
 #include "access/gist.h"
 #include "access/itup.h"
-#include "access/xlog.h"
-#include "access/xlogdefs.h"
-#include "fmgr.h"
+#include "storage/bufmgr.h"
 
 #define GIST_UNLOCK BUFFER_LOCK_UNLOCK
 #define GIST_SHARE	BUFFER_LOCK_SHARE

src/include/access/hash.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/hash.h,v 1.87 2008/04/10 22:25:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/hash.h,v 1.88 2008/06/19 00:46:05 alvherre Exp $
  *
  * NOTES
  *		modeled after Margo Seltzer's hash implementation for unix.
@@ -17,12 +17,13 @@
 #ifndef HASH_H
 #define HASH_H
 
+#include "access/genam.h"
 #include "access/itup.h"
-#include "access/relscan.h"
 #include "access/sdir.h"
 #include "access/xlog.h"
 #include "fmgr.h"
 #include "storage/lock.h"
+#include "utils/relcache.h"
 
 /*
  * Mapping from hash bucket number to physical block number of bucket's

src/include/access/heapam.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.136 2008/06/12 09:12:31 heikki Exp $
+ * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.137 2008/06/19 00:46:06 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,11 +15,13 @@
 #define HEAPAM_H
 
 #include "access/htup.h"
-#include "access/relscan.h"
 #include "access/sdir.h"
+#include "access/skey.h"
 #include "access/xlog.h"
 #include "nodes/primnodes.h"
+#include "storage/bufpage.h"
 #include "storage/lock.h"
+#include "utils/relcache.h"
 #include "utils/snapshot.h"
 
 
@@ -50,6 +52,15 @@ extern Relation heap_openrv(const RangeVar *relation, LOCKMODE lockmode);
 
 #define heap_close(r,l)  relation_close(r,l)
 
+/* struct definition appears in relscan.h */
+typedef struct HeapScanDescData *HeapScanDesc;
+
+/*
+ * HeapScanIsValid
+ *		True iff the heap scan is valid.
+ */
+#define HeapScanIsValid(scan) PointerIsValid(scan)
+
 extern HeapScanDesc heap_beginscan(Relation relation, Snapshot snapshot,
 			   int nkeys, ScanKey key);
 extern HeapScanDesc heap_beginscan_strat(Relation relation, Snapshot snapshot,

src/include/access/hio.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/hio.h,v 1.35 2008/01/01 19:45:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/hio.h,v 1.36 2008/06/19 00:46:06 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,7 +15,7 @@
 #define HIO_H
 
 #include "access/htup.h"
-#include "utils/rel.h"
+#include "utils/relcache.h"
 #include "storage/buf.h"
 
 extern void RelationPutHeapTuple(Relation relation, Buffer buffer,

src/include/access/nbtree.h

@@ -7,15 +7,15 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/nbtree.h,v 1.119 2008/06/06 22:35:22 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/access/nbtree.h,v 1.120 2008/06/19 00:46:06 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef NBTREE_H
 #define NBTREE_H
 
+#include "access/genam.h"
 #include "access/itup.h"
-#include "access/relscan.h"
 #include "access/sdir.h"
 #include "access/xlog.h"
 #include "access/xlogutils.h"

src/include/access/relscan.h

@@ -7,18 +7,15 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/relscan.h,v 1.65 2008/05/12 00:00:53 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/access/relscan.h,v 1.66 2008/06/19 00:46:06 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef RELSCAN_H
 #define RELSCAN_H
 
-#include "access/htup.h"
-#include "access/skey.h"
-#include "storage/bufpage.h"
-#include "utils/rel.h"
-#include "utils/snapshot.h"
+#include "access/genam.h"
+#include "access/heapam.h"
 
 
 typedef struct HeapScanDescData
@@ -54,8 +51,6 @@ typedef struct HeapScanDescData
 	OffsetNumber rs_vistuples[MaxHeapTuplesPerPage];	/* their offsets */
 } HeapScanDescData;
 
-typedef HeapScanDescData *HeapScanDesc;
-
 /*
  * We use the same IndexScanDescData structure for both amgettuple-based
  * and amgetbitmap-based index scans.  Some fields are only relevant in
@@ -89,19 +84,13 @@ typedef struct IndexScanDescData
 	TransactionId xs_prev_xmax; /* previous HOT chain member's XMAX, if any */
 } IndexScanDescData;
 
-typedef IndexScanDescData *IndexScanDesc;
-
-
-/*
- * HeapScanIsValid
- *		True iff the heap scan is valid.
- */
-#define HeapScanIsValid(scan) PointerIsValid(scan)
-
-/*
- * IndexScanIsValid
- *		True iff the index scan is valid.
- */
-#define IndexScanIsValid(scan) PointerIsValid(scan)
+/* Struct for heap-or-index scans of system tables */
+typedef struct SysScanDescData
+{
+	Relation	heap_rel;		/* catalog being scanned */
+	Relation	irel;			/* NULL if doing heap scan */
+	HeapScanDesc scan;			/* only valid in heap-scan case */
+	IndexScanDesc iscan;		/* only valid in index-scan case */
+} SysScanDescData;
 
 #endif   /* RELSCAN_H */

src/include/access/rewriteheap.h

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/rewriteheap.h,v 1.4 2008/01/01 19:45:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/rewriteheap.h,v 1.5 2008/06/19 00:46:06 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -14,7 +14,7 @@
 #define REWRITE_HEAP_H
 
 #include "access/htup.h"
-#include "utils/rel.h"
+#include "utils/relcache.h"
 
 /* struct definition is private to rewriteheap.c */
 typedef struct RewriteStateData *RewriteState;

src/include/access/tuptoaster.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 2000-2008, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/access/tuptoaster.h,v 1.39 2008/05/12 00:00:53 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/access/tuptoaster.h,v 1.40 2008/06/19 00:46:06 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,7 +15,7 @@
 
 #include "access/htup.h"
 #include "storage/bufpage.h"
-#include "utils/rel.h"
+#include "utils/relcache.h"
 
 /*
  * This enables de-toasting of index entries.  Needed until VACUUM is

src/include/access/xlogutils.h

@@ -6,13 +6,15 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/xlogutils.h,v 1.24 2008/06/12 09:12:31 heikki Exp $
+ * $PostgreSQL: pgsql/src/include/access/xlogutils.h,v 1.25 2008/06/19 00:46:06 alvherre Exp $
  */
 #ifndef XLOG_UTILS_H
 #define XLOG_UTILS_H
 
 #include "storage/buf.h"
-#include "utils/rel.h"
+#include "storage/relfilenode.h"
+#include "storage/block.h"
+#include "utils/relcache.h"
 
 
 extern void XLogCheckInvalidPages(void);