Restructure local-buffer handling per recent pghackers discussion.

The local buffer manager is no longer used for newly-created relations
(unless they are TEMP); a new non-TEMP relation goes through the shared
bufmgr and thus will participate normally in checkpoints.  But TEMP relations
use the local buffer manager throughout their lifespan.  Also, operations
in TEMP relations are not logged in WAL, thus improving performance.
Since it's no longer necessary to fsync relations as they move out of the
local buffers into shared buffers, quite a lot of smgr.c/md.c/fd.c code
is no longer needed and has been removed: there's no concept of a dirty
relation anymore in md.c/fd.c, and we never fsync anything but WAL.
Still TODO: improve local buffer management algorithms so that it would
be reasonable to increase NLocBuffer.

1 files changed, 18 insertions, 2 deletions

diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index f8a05b619de..a33fcd24a40 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/sequence.c,v 1.83 2002/07/16 22:12:19 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/sequence.c,v 1.84 2002/08/06 02:36:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -237,6 +237,7 @@ DefineSequence(CreateSeqStmt *seq)
 	 * means two log records instead of one :-(
 	 */
 	LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+
 	START_CRIT_SECTION();
 
 	{
@@ -260,6 +261,8 @@ DefineSequence(CreateSeqStmt *seq)
 		tuple->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
 	}
 
+	/* XLOG stuff */
+	if (!rel->rd_istemp)
 	{
 		xl_seq_rec	xlrec;
 		XLogRecPtr	recptr;
@@ -287,6 +290,7 @@ DefineSequence(CreateSeqStmt *seq)
 		PageSetLSN(page, recptr);
 		PageSetSUI(page, ThisStartUpID);
 	}
+
 	END_CRIT_SECTION();
 
 	LockBuffer(buf, BUFFER_LOCK_UNLOCK);
@@ -437,7 +441,9 @@ nextval(PG_FUNCTION_ARGS)
 	elm->cached = last;			/* last fetched number */
 
 	START_CRIT_SECTION();
-	if (logit)
+
+	/* XLOG stuff */
+	if (logit && !seqrel->rd_istemp)
 	{
 		xl_seq_rec	xlrec;
 		XLogRecPtr	recptr;
@@ -449,9 +455,11 @@ nextval(PG_FUNCTION_ARGS)
 		rdata[0].len = sizeof(xl_seq_rec);
 		rdata[0].next = &(rdata[1]);
 
+		/* set values that will be saved in xlog */
 		seq->last_value = next;
 		seq->is_called = true;
 		seq->log_cnt = 0;
+
 		rdata[1].buffer = InvalidBuffer;
 		rdata[1].data = (char *) page + ((PageHeader) page)->pd_upper;
 		rdata[1].len = ((PageHeader) page)->pd_special -
@@ -468,6 +476,7 @@ nextval(PG_FUNCTION_ARGS)
 	seq->last_value = last;		/* last fetched number */
 	seq->is_called = true;
 	seq->log_cnt = log;			/* how much is logged */
+
 	END_CRIT_SECTION();
 
 	LockBuffer(buf, BUFFER_LOCK_UNLOCK);
@@ -550,6 +559,9 @@ do_setval(RangeVar *sequence, int64 next, bool iscalled)
 								 * values) */
 
 	START_CRIT_SECTION();
+
+	/* XLOG stuff */
+	if (!seqrel->rd_istemp)
 	{
 		xl_seq_rec	xlrec;
 		XLogRecPtr	recptr;
@@ -562,9 +574,11 @@ do_setval(RangeVar *sequence, int64 next, bool iscalled)
 		rdata[0].len = sizeof(xl_seq_rec);
 		rdata[0].next = &(rdata[1]);
 
+		/* set values that will be saved in xlog */
 		seq->last_value = next;
 		seq->is_called = true;
 		seq->log_cnt = 0;
+
 		rdata[1].buffer = InvalidBuffer;
 		rdata[1].data = (char *) page + ((PageHeader) page)->pd_upper;
 		rdata[1].len = ((PageHeader) page)->pd_special -
@@ -576,10 +590,12 @@ do_setval(RangeVar *sequence, int64 next, bool iscalled)
 		PageSetLSN(page, recptr);
 		PageSetSUI(page, ThisStartUpID);
 	}
+
 	/* save info in sequence relation */
 	seq->last_value = next;		/* last fetched number */
 	seq->is_called = iscalled;
 	seq->log_cnt = (iscalled) ? 0 : 1;
+
 	END_CRIT_SECTION();
 
 	LockBuffer(buf, BUFFER_LOCK_UNLOCK);