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Fix coredump seen when doing mergejoin between indexed tables,

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for example in the regression test database, try
select * from tenk1 t1, tenk1 t2 where t1.unique1 = t2.unique2;
6.5 has this same bug ...
This commit is contained in:
Tom Lane 1999-07-30 00:56:17 +00:00
parent 161be69544
commit 7d572886d6
1 changed files with 23 additions and 9 deletions
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32
src/backend/optimizer/util/pathnode.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.49 1999/07/27 03:51:05 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.50 1999/07/30 00:56:17 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -329,11 +329,16 @@ create_index_path(Query *root,
/* Note that we are making a pathnode for a single-scan indexscan;
* therefore, both indexid and indexqual should be single-element
* lists (unless indexqual is empty).
* lists. We initialize indexqual to contain one empty sublist,
* representing a single index traversal with no index restriction
* conditions. If we do have restriction conditions to use, they
* will get inserted below.
*/
Assert(length(index->relids) == 1);
pathnode->indexid = index->relids;
pathnode->indexqual = lcons(NIL, NIL);
pathnode->indexkeys = index->indexkeys;
pathnode->indexqual = NIL;
/*
* The index must have an ordering for the path to have (ordering)
@ -358,14 +363,19 @@ create_index_path(Query *root,
if (is_join_scan || restriction_clauses == NULL)
{
/*
* Indices used for joins or sorting result nodes don't restrict
* the result at all, they simply order it, so compute the scan
* cost accordingly -- use a selectivity of 1.0.
*
* is the statement above really true? what about IndexScan as the
* inner of a join?
*
* I think it's OK --- this routine is only used to make index paths
* for mergejoins and sorts. Index paths used as the inner side of
* a nestloop join do provide restriction, but they are not made
* with this code. See index_innerjoin() in indxpath.c.
*/
/* is the statement above really true? what about IndexScan as the
inner of a join? */
pathnode->path.path_cost = cost_index(lfirsti(index->relids),
index->pages,
1.0,
@ -378,8 +388,8 @@ create_index_path(Query *root,
else
{
/*
* Compute scan cost for the case when 'index' is used with a
* restriction clause.
* Compute scan cost for the case when 'index' is used with
* restriction clause(s).
*/
List *indexquals;
float npages;
@ -390,6 +400,11 @@ create_index_path(Query *root,
/* expand special operators to indexquals the executor can handle */
indexquals = expand_indexqual_conditions(indexquals);
/* Insert qual list into 1st sublist of pathnode->indexqual;
* we already made the cons cell above, no point in wasting it...
*/
lfirst(pathnode->indexqual) = indexquals;
index_selectivity(root,
lfirsti(rel->relids),
lfirsti(index->relids),
@ -397,7 +412,6 @@ create_index_path(Query *root,
&npages,
&selec);
pathnode->indexqual = lcons(indexquals, NIL);
pathnode->path.path_cost = cost_index(lfirsti(index->relids),
(int) npages,
selec,