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Concurrency for GiST

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- full concurrency for insert/update/select/vacuum:
        - select and vacuum never locks more than one page simultaneously
        - select (gettuple) hasn't any lock across it's calls
        - insert never locks more than two page simultaneously:
                - during search of leaf to insert it locks only one page
                  simultaneously
                - while walk upward to the root it locked only parent (may be
                  non-direct parent) and child. One of them X-lock, another may
                  be S- or X-lock
- 'vacuum full' locks index
- improve gistgetmulti
- simplify XLOG records

Fix bug in index_beginscan_internal: LockRelation may clean
  rd_aminfo structure, so move GET_REL_PROCEDURE after LockRelation
This commit is contained in:
Teodor Sigaev
2005-06-27 12:45:23 +00:00
parent c3be085ab7
commit e8cab5fe49
12 changed files with 994 additions and 598 deletions
Download Patch File Download Diff File Expand all files Collapse all files

103
src/backend/access/gist/gistscan.c
View File

@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.58 2005/05/17 03:34:18 neilc Exp $
* $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.59 2005/06/27 12:45:22 teodor Exp $
*
*-------------------------------------------------------------------------
*/
@ -24,11 +24,10 @@
static void gistregscan(IndexScanDesc scan);
static void gistdropscan(IndexScanDesc scan);
static void gistadjone(IndexScanDesc scan, int op, BlockNumber blkno,
OffsetNumber offnum);
static void adjuststack(GISTSTACK *stk, BlockNumber blkno);
static void adjustiptr(IndexScanDesc scan, ItemPointer iptr,
int op, BlockNumber blkno, OffsetNumber offnum);
static void gistfreestack(GISTSTACK *s);
OffsetNumber offnum, XLogRecPtr newlsn, XLogRecPtr oldlsn);
static void adjustiptr(IndexScanDesc scan, ItemPointer iptr, GISTSearchStack *stk,
int op, BlockNumber blkno, OffsetNumber offnum, XLogRecPtr newlsn, XLogRecPtr oldlsn);
static void gistfreestack(GISTSearchStack *s);
/*
* Whenever we start a GiST scan in a backend, we register it in
@ -139,7 +138,7 @@ gistmarkpos(PG_FUNCTION_ARGS)
{
IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
GISTScanOpaque so;
GISTSTACK *o,
GISTSearchStack *o,
*n,
*tmp;
@ -156,12 +155,13 @@ gistmarkpos(PG_FUNCTION_ARGS)
/* copy the parent stack from the current item data */
while (n != NULL)
{
tmp = (GISTSTACK *) palloc(sizeof(GISTSTACK));
tmp->offset = n->offset;
tmp = (GISTSearchStack *) palloc(sizeof(GISTSearchStack));
tmp->lsn = n->lsn;
tmp->parentlsn = n->parentlsn;
tmp->block = n->block;
tmp->parent = o;
tmp->next = o;
o = tmp;
n = n->parent;
n = n->next;
}
gistfreestack(so->markstk);
@ -187,7 +187,7 @@ gistrestrpos(PG_FUNCTION_ARGS)
{
IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
GISTScanOpaque so;
GISTSTACK *o,
GISTSearchStack *o,
*n,
*tmp;
@ -204,12 +204,13 @@ gistrestrpos(PG_FUNCTION_ARGS)
/* copy the parent stack from the current item data */
while (n != NULL)
{
tmp = (GISTSTACK *) palloc(sizeof(GISTSTACK));
tmp->offset = n->offset;
tmp = (GISTSearchStack *) palloc(sizeof(GISTSearchStack));
tmp->lsn = n->lsn;
tmp->parentlsn = n->parentlsn;
tmp->block = n->block;
tmp->parent = o;
tmp->next = o;
o = tmp;
n = n->parent;
n = n->next;
}
gistfreestack(so->stack);
@ -253,6 +254,7 @@ gistendscan(PG_FUNCTION_ARGS)
pfree(scan->opaque);
}
gistdropscan(scan);
PG_RETURN_VOID();
@ -331,16 +333,19 @@ ReleaseResources_gist(void)
}
void
gistadjscans(Relation rel, int op, BlockNumber blkno, OffsetNumber offnum)
gistadjscans(Relation rel, int op, BlockNumber blkno, OffsetNumber offnum, XLogRecPtr newlsn, XLogRecPtr oldlsn)
{
GISTScanList l;
Oid relid;
if ( XLogRecPtrIsInvalid(newlsn) || XLogRecPtrIsInvalid(oldlsn) )
return;
relid = RelationGetRelid(rel);
for (l = GISTScans; l != NULL; l = l->gsl_next)
{
if (l->gsl_scan->indexRelation->rd_id == relid)
gistadjone(l->gsl_scan, op, blkno, offnum);
gistadjone(l->gsl_scan, op, blkno, offnum, newlsn, oldlsn);
}
}
@ -358,20 +363,12 @@ static void
gistadjone(IndexScanDesc scan,
int op,
BlockNumber blkno,
OffsetNumber offnum)
OffsetNumber offnum, XLogRecPtr newlsn, XLogRecPtr oldlsn)
{
GISTScanOpaque so;
GISTScanOpaque so = (GISTScanOpaque) scan->opaque ;
adjustiptr(scan, &(scan->currentItemData), op, blkno, offnum);
adjustiptr(scan, &(scan->currentMarkData), op, blkno, offnum);
so = (GISTScanOpaque) scan->opaque;
if (op == GISTOP_SPLIT)
{
adjuststack(so->stack, blkno);
adjuststack(so->markstk, blkno);
}
adjustiptr(scan, &(scan->currentItemData), so->stack, op, blkno, offnum, newlsn, oldlsn);
adjustiptr(scan, &(scan->currentMarkData), so->markstk, op, blkno, offnum, newlsn, oldlsn);
}
/*
@ -383,10 +380,10 @@ gistadjone(IndexScanDesc scan,
*/
static void
adjustiptr(IndexScanDesc scan,
ItemPointer iptr,
ItemPointer iptr, GISTSearchStack *stk,
int op,
BlockNumber blkno,
OffsetNumber offnum)
OffsetNumber offnum, XLogRecPtr newlsn, XLogRecPtr oldlsn)
{
OffsetNumber curoff;
GISTScanOpaque so;
@ -402,7 +399,7 @@ adjustiptr(IndexScanDesc scan,
{
case GISTOP_DEL:
/* back up one if we need to */
if (curoff >= offnum)
if (curoff >= offnum && XLByteEQ(stk->lsn, oldlsn) ) /* the same vesrion of page */
{
if (curoff > FirstOffsetNumber)
{
@ -421,18 +418,9 @@ adjustiptr(IndexScanDesc scan,
else
so->flags |= GS_MRKBEFORE;
}
stk->lsn = newlsn;
}
break;
case GISTOP_SPLIT:
/* back to start of page on split */
ItemPointerSet(iptr, blkno, FirstOffsetNumber);
if (iptr == &(scan->currentItemData))
so->flags &= ~GS_CURBEFORE;
else
so->flags &= ~GS_MRKBEFORE;
break;
default:
elog(ERROR, "Bad operation in GiST scan adjust: %d", op);
}
@ -440,37 +428,12 @@ adjustiptr(IndexScanDesc scan,
}
}
/*
* adjuststack() -- adjust the supplied stack for a split on a page in
* the index we're scanning.
*
* If a page on our parent stack has split, we need to back up to the
* beginning of the page and rescan it. The reason for this is that
* the split algorithm for GiSTs doesn't order tuples in any useful
* way on a single page. This means on that a split, we may wind up
* looking at some heap tuples more than once. This is handled in the
* access method update code for heaps; if we've modified the tuple we
* are looking at already in this transaction, we ignore the update
* request.
*/
static void
adjuststack(GISTSTACK *stk, BlockNumber blkno)
{
while (stk != NULL)
{
if (stk->block == blkno)
stk->offset = FirstOffsetNumber;
stk = stk->parent;
}
}
static void
gistfreestack(GISTSTACK *s)
gistfreestack(GISTSearchStack *s)
{
while (s != NULL)
{
GISTSTACK *p = s->parent;
GISTSearchStack *p = s->next;
pfree(s);
s = p;
}