Provide a build-time option to store large relations as single files, rather

than dividing them into 1GB segments as has been our longtime practice.  This
requires working support for large files in the operating system; at least for
the time being, it won't be the default.

Zdenek Kotala

1 files changed, 38 insertions, 38 deletions

diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index 543574be400..6ea4a00b017 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.135 2008/01/01 19:45:52 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.136 2008/03/10 20:06:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -89,16 +89,16 @@
  *
  *	All MdfdVec objects are palloc'd in the MdCxt memory context.
  *
- *	Defining LET_OS_MANAGE_FILESIZE disables the segmentation logic,
- *	for use on machines that support large files.  Beware that that
- *	code has not been tested in a long time and is probably bit-rotted.
+ *	On platforms that support large files, USE_SEGMENTED_FILES can be
+ *	#undef'd to disable the segmentation logic.  In that case each
+ *	relation is a single operating-system file.
  */
 
 typedef struct _MdfdVec
 {
 	File		mdfd_vfd;		/* fd number in fd.c's pool */
 	BlockNumber mdfd_segno;		/* segment number, from 0 */
-#ifndef LET_OS_MANAGE_FILESIZE	/* for large relations */
+#ifdef USE_SEGMENTED_FILES
 	struct _MdfdVec *mdfd_chain;	/* next segment, or NULL */
 #endif
 } MdfdVec;
@@ -162,7 +162,7 @@ static void register_dirty_segment(SMgrRelation reln, MdfdVec *seg);
 static void register_unlink(RelFileNode rnode);
 static MdfdVec *_fdvec_alloc(void);
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 static MdfdVec *_mdfd_openseg(SMgrRelation reln, BlockNumber segno,
 			  int oflags);
 #endif
@@ -258,7 +258,7 @@ mdcreate(SMgrRelation reln, bool isRedo)
 
 	reln->md_fd->mdfd_vfd = fd;
 	reln->md_fd->mdfd_segno = 0;
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	reln->md_fd->mdfd_chain = NULL;
 #endif
 }
@@ -344,7 +344,7 @@ mdunlink(RelFileNode rnode, bool isRedo)
 							rnode.relNode)));
 	}
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	/* Delete the additional segments, if any */
 	else
 	{
@@ -395,7 +395,7 @@ mdunlink(RelFileNode rnode, bool isRedo)
 void
 mdextend(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
 {
-	long		seekpos;
+	off_t		seekpos;
 	int			nbytes;
 	MdfdVec    *v;
 
@@ -420,11 +420,11 @@ mdextend(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
 
 	v = _mdfd_getseg(reln, blocknum, isTemp, EXTENSION_CREATE);
 
-#ifndef LET_OS_MANAGE_FILESIZE
-	seekpos = (long) (BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE)));
-	Assert(seekpos < BLCKSZ * RELSEG_SIZE);
+#ifdef USE_SEGMENTED_FILES
+	seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
+	Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
 #else
-	seekpos = (long) (BLCKSZ * (blocknum));
+	seekpos = (off_t) BLCKSZ * blocknum;
 #endif
 
 	/*
@@ -469,7 +469,7 @@ mdextend(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
 	if (!isTemp)
 		register_dirty_segment(reln, v);
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	Assert(_mdnblocks(reln, v) <= ((BlockNumber) RELSEG_SIZE));
 #endif
 }
@@ -530,7 +530,7 @@ mdopen(SMgrRelation reln, ExtensionBehavior behavior)
 
 	mdfd->mdfd_vfd = fd;
 	mdfd->mdfd_segno = 0;
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	mdfd->mdfd_chain = NULL;
 	Assert(_mdnblocks(reln, mdfd) <= ((BlockNumber) RELSEG_SIZE));
 #endif
@@ -552,7 +552,7 @@ mdclose(SMgrRelation reln)
 
 	reln->md_fd = NULL;			/* prevent dangling pointer after error */
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	while (v != NULL)
 	{
 		MdfdVec    *ov = v;
@@ -577,17 +577,17 @@ mdclose(SMgrRelation reln)
 void
 mdread(SMgrRelation reln, BlockNumber blocknum, char *buffer)
 {
-	long		seekpos;
+	off_t		seekpos;
 	int			nbytes;
 	MdfdVec    *v;
 
 	v = _mdfd_getseg(reln, blocknum, false, EXTENSION_FAIL);
 
-#ifndef LET_OS_MANAGE_FILESIZE
-	seekpos = (long) (BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE)));
-	Assert(seekpos < BLCKSZ * RELSEG_SIZE);
+#ifdef USE_SEGMENTED_FILES
+	seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
+	Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
 #else
-	seekpos = (long) (BLCKSZ * (blocknum));
+	seekpos = (off_t) BLCKSZ * blocknum;
 #endif
 
 	if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
@@ -642,7 +642,7 @@ mdread(SMgrRelation reln, BlockNumber blocknum, char *buffer)
 void
 mdwrite(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
 {
-	long		seekpos;
+	off_t		seekpos;
 	int			nbytes;
 	MdfdVec    *v;
 
@@ -653,11 +653,11 @@ mdwrite(SMgrRelation reln, BlockNumber blocknum, char *buffer, bool isTemp)
 
 	v = _mdfd_getseg(reln, blocknum, isTemp, EXTENSION_FAIL);
 
-#ifndef LET_OS_MANAGE_FILESIZE
-	seekpos = (long) (BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE)));
-	Assert(seekpos < BLCKSZ * RELSEG_SIZE);
+#ifdef USE_SEGMENTED_FILES
+	seekpos = (off_t) BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE));
+	Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
 #else
-	seekpos = (long) (BLCKSZ * (blocknum));
+	seekpos = (off_t) BLCKSZ * blocknum;
 #endif
 
 	if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
@@ -708,7 +708,7 @@ mdnblocks(SMgrRelation reln)
 {
 	MdfdVec    *v = mdopen(reln, EXTENSION_FAIL);
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	BlockNumber nblocks;
 	BlockNumber segno = 0;
 
@@ -778,7 +778,7 @@ mdtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp)
 	MdfdVec    *v;
 	BlockNumber curnblk;
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	BlockNumber priorblocks;
 #endif
 
@@ -804,7 +804,7 @@ mdtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp)
 
 	v = mdopen(reln, EXTENSION_FAIL);
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	priorblocks = 0;
 	while (v != NULL)
 	{
@@ -843,7 +843,7 @@ mdtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp)
 			 */
 			BlockNumber lastsegblocks = nblocks - priorblocks;
 
-			if (FileTruncate(v->mdfd_vfd, lastsegblocks * BLCKSZ) < 0)
+			if (FileTruncate(v->mdfd_vfd, (off_t) lastsegblocks * BLCKSZ) < 0)
 				ereport(ERROR,
 						(errcode_for_file_access(),
 						 errmsg("could not truncate relation %u/%u/%u to %u blocks: %m",
@@ -867,7 +867,8 @@ mdtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp)
 		priorblocks += RELSEG_SIZE;
 	}
 #else
-	if (FileTruncate(v->mdfd_vfd, nblocks * BLCKSZ) < 0)
+	/* For unsegmented files, it's a lot easier */
+	if (FileTruncate(v->mdfd_vfd, (off_t) nblocks * BLCKSZ) < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
 			  errmsg("could not truncate relation %u/%u/%u to %u blocks: %m",
@@ -900,7 +901,7 @@ mdimmedsync(SMgrRelation reln)
 
 	v = mdopen(reln, EXTENSION_FAIL);
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	while (v != NULL)
 	{
 		if (FileSync(v->mdfd_vfd) < 0)
@@ -917,8 +918,7 @@ mdimmedsync(SMgrRelation reln)
 	if (FileSync(v->mdfd_vfd) < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
-				 errmsg("could not fsync segment %u of relation %u/%u/%u: %m",
-						v->mdfd_segno,
+				 errmsg("could not fsync relation %u/%u/%u: %m",
 						reln->smgr_rnode.spcNode,
 						reln->smgr_rnode.dbNode,
 						reln->smgr_rnode.relNode)));
@@ -1453,7 +1453,7 @@ _fdvec_alloc(void)
 	return (MdfdVec *) MemoryContextAlloc(MdCxt, sizeof(MdfdVec));
 }
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 
 /*
  * Open the specified segment of the relation,
@@ -1499,7 +1499,7 @@ _mdfd_openseg(SMgrRelation reln, BlockNumber segno, int oflags)
 	/* all done */
 	return v;
 }
-#endif   /* LET_OS_MANAGE_FILESIZE */
+#endif   /* USE_SEGMENTED_FILES */
 
 /*
  *	_mdfd_getseg() -- Find the segment of the relation holding the
@@ -1515,7 +1515,7 @@ _mdfd_getseg(SMgrRelation reln, BlockNumber blkno, bool isTemp,
 {
 	MdfdVec    *v = mdopen(reln, behavior);
 
-#ifndef LET_OS_MANAGE_FILESIZE
+#ifdef USE_SEGMENTED_FILES
 	BlockNumber targetseg;
 	BlockNumber nextsegno;
 
@@ -1588,7 +1588,7 @@ _mdfd_getseg(SMgrRelation reln, BlockNumber blkno, bool isTemp,
 static BlockNumber
 _mdnblocks(SMgrRelation reln, MdfdVec *seg)
 {
-	long		len;
+	off_t		len;
 
 	len = FileSeek(seg->mdfd_vfd, 0L, SEEK_END);
 	if (len < 0)