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First steps towards index scans with heap access decoupled from index

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access: define new index access method functions 'amgetmulti' that can
fetch multiple TIDs per call.  (The functions exist but are totally
untested as yet.)  Since I was modifying pg_am anyway, remove the
no-longer-needed 'rel' parameter from amcostestimate functions, and
also remove the vestigial amowner column that was creating useless
work for Alvaro's shared-object-dependencies project.
Initdb forced due to changes in pg_am.
This commit is contained in:
Tom Lane
2005-03-27 23:53:05 +00:00
parent 351519affc
commit bf3dbb5881
20 changed files with 535 additions and 174 deletions
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29
src/backend/access/heap/heapam.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.184 2005/03/20 23:40:23 neilc Exp $
* $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.185 2005/03/27 23:52:58 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -933,18 +933,35 @@ heap_release_fetch(Relation relation,
* Need share lock on buffer to examine tuple commit status.
*/
LockBuffer(buffer, BUFFER_LOCK_SHARE);
dp = (PageHeader) BufferGetPage(buffer);
/*
* We'd better check for out-of-range offnum in case of VACUUM since
* the TID was obtained.
*/
offnum = ItemPointerGetOffsetNumber(tid);
if (offnum < FirstOffsetNumber || offnum > PageGetMaxOffsetNumber(dp))
{
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
if (keep_buf)
*userbuf = buffer;
else
{
ReleaseBuffer(buffer);
*userbuf = InvalidBuffer;
}
tuple->t_datamcxt = NULL;
tuple->t_data = NULL;
return false;
}
/*
* get the item line pointer corresponding to the requested tid
*/
dp = (PageHeader) BufferGetPage(buffer);
offnum = ItemPointerGetOffsetNumber(tid);
lp = PageGetItemId(dp, offnum);
/*
* must check for deleted tuple (see for example analyze.c, which is
* careful to pass an offnum in range, but doesn't know if the offnum
* actually corresponds to an undeleted tuple).
* Must check for deleted tuple.
*/
if (!ItemIdIsUsed(lp))
{