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Fix 'all at one page bug' in picksplit method of R-tree emulation. Add defense

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from buggy user-defined picksplit to GiST.
This commit is contained in:
Teodor Sigaev
2009-04-06 14:27:27 +00:00
parent 1eef90d0a2
commit 09368d23db
2 changed files with 175 additions and 54 deletions
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106
src/backend/access/gist/gistsplit.c
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@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/gist/gistsplit.c,v 1.7 2009/01/01 17:23:35 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/gist/gistsplit.c,v 1.8 2009/04/06 14:27:27 teodor Exp $
*
*-------------------------------------------------------------------------
*/
@ -280,6 +280,63 @@ supportSecondarySplit(Relation r, GISTSTATE *giststate, int attno, GIST_SPLITVEC
sv->spl_ldatum_exists = sv->spl_rdatum_exists = false;
}
/*
* Trivial picksplit implementaion. Function called only
* if user-defined picksplit puts all keys to the one page.
* That is a bug of user-defined picksplit but we'd like
* to "fix" that.
*/
static void
genericPickSplit(GISTSTATE *giststate, GistEntryVector *entryvec, GIST_SPLITVEC *v, int attno)
{
OffsetNumber i,
maxoff;
int nbytes;
GistEntryVector *evec;
maxoff = entryvec->n - 1;
nbytes = (maxoff + 2) * sizeof(OffsetNumber);
v->spl_left = (OffsetNumber *) palloc(nbytes);
v->spl_right = (OffsetNumber *) palloc(nbytes);
v->spl_nleft = v->spl_nright = 0;
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
if (i <= (maxoff - FirstOffsetNumber + 1) / 2)
{
v->spl_left[v->spl_nleft] = i;
v->spl_nleft++;
}
else
{
v->spl_right[v->spl_nright] = i;
v->spl_nright++;
}
}
/*
* Form unions of each page
*/
evec = palloc( sizeof(GISTENTRY) * entryvec->n + GEVHDRSZ );
evec->n = v->spl_nleft;
memcpy(evec->vector, entryvec->vector + FirstOffsetNumber,
sizeof(GISTENTRY) * evec->n);
v->spl_ldatum = FunctionCall2(&giststate->unionFn[attno],
PointerGetDatum(evec),
PointerGetDatum(&nbytes));
evec->n = v->spl_nright;
memcpy(evec->vector, entryvec->vector + FirstOffsetNumber + v->spl_nleft,
sizeof(GISTENTRY) * evec->n);
v->spl_rdatum = FunctionCall2(&giststate->unionFn[attno],
PointerGetDatum(evec),
PointerGetDatum(&nbytes));
}
/*
* Calls user picksplit method for attno columns to split vector to
* two vectors. May use attno+n columns data to
@ -296,7 +353,7 @@ gistUserPicksplit(Relation r, GistEntryVector *entryvec, int attno, GistSplitVec
/*
* now let the user-defined picksplit function set up the split vector; in
* entryvec have no null value!!
* entryvec there is no null value!!
*/
sv->spl_ldatum_exists = (v->spl_lisnull[attno]) ? false : true;
@ -308,18 +365,43 @@ gistUserPicksplit(Relation r, GistEntryVector *entryvec, int attno, GistSplitVec
PointerGetDatum(entryvec),
PointerGetDatum(sv));
/* compatibility with old code */
if (sv->spl_left[sv->spl_nleft - 1] == InvalidOffsetNumber)
sv->spl_left[sv->spl_nleft - 1] = (OffsetNumber) (entryvec->n - 1);
if (sv->spl_right[sv->spl_nright - 1] == InvalidOffsetNumber)
sv->spl_right[sv->spl_nright - 1] = (OffsetNumber) (entryvec->n - 1);
if (sv->spl_ldatum_exists || sv->spl_rdatum_exists)
if ( sv->spl_nleft == 0 || sv->spl_nright == 0 )
{
elog(LOG, "PickSplit method of %d columns of index '%s' doesn't support secondary split",
attno + 1, RelationGetRelationName(r));
ereport(DEBUG1,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("Picksplit method for %d column of index \"%s\" failed",
attno+1, RelationGetRelationName(r)),
errhint("Index is not optimal, to optimize it contact developer or try to use the column as a second one in create index command")));
supportSecondarySplit(r, giststate, attno, sv, v->spl_lattr[attno], v->spl_rattr[attno]);
/*
* Reinit GIST_SPLITVEC. Although that fields are not used
* by genericPickSplit(), let us set up it for further processing
*/
sv->spl_ldatum_exists = (v->spl_lisnull[attno]) ? false : true;
sv->spl_rdatum_exists = (v->spl_risnull[attno]) ? false : true;
sv->spl_ldatum = v->spl_lattr[attno];
sv->spl_rdatum = v->spl_rattr[attno];
genericPickSplit(giststate, entryvec, sv, attno);
if (sv->spl_ldatum_exists || sv->spl_rdatum_exists)
supportSecondarySplit(r, giststate, attno, sv, v->spl_lattr[attno], v->spl_rattr[attno]);
}
else
{
/* compatibility with old code */
if (sv->spl_left[sv->spl_nleft - 1] == InvalidOffsetNumber)
sv->spl_left[sv->spl_nleft - 1] = (OffsetNumber) (entryvec->n - 1);
if (sv->spl_right[sv->spl_nright - 1] == InvalidOffsetNumber)
sv->spl_right[sv->spl_nright - 1] = (OffsetNumber) (entryvec->n - 1);
if (sv->spl_ldatum_exists || sv->spl_rdatum_exists)
{
elog(LOG, "PickSplit method of %d columns of index '%s' doesn't support secondary split",
attno + 1, RelationGetRelationName(r));
supportSecondarySplit(r, giststate, attno, sv, v->spl_lattr[attno], v->spl_rattr[attno]);
}
}
v->spl_lattr[attno] = sv->spl_ldatum;