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IN clauses appearing at top level of WHERE can now be handled as joins.

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There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
This commit is contained in:
Tom Lane
2003-01-20 18:55:07 +00:00
parent be2b660ecd
commit bdfbfde1b1
47 changed files with 2075 additions and 875 deletions
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18
src/backend/optimizer/util/relnode.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.43 2003/01/15 19:35:44 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.44 2003/01/20 18:54:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -140,6 +140,7 @@ make_base_rel(Query *root, int relid)
rel->pathlist = NIL;
rel->cheapest_startup_path = NULL;
rel->cheapest_total_path = NULL;
rel->cheapest_unique_path = NULL;
rel->pruneable = true;
rel->rtekind = rte->rtekind;
rel->indexlist = NIL;
@ -244,6 +245,7 @@ find_join_rel(Query *root, Relids relids)
* Returns relation entry corresponding to the union of two given rels,
* creating a new relation entry if none already exists.
*
* 'joinrelids' is the Relids list that uniquely identifies the join
* 'outer_rel' and 'inner_rel' are relation nodes for the relations to be
* joined
* 'jointype': type of join (inner/outer)
@ -256,27 +258,20 @@ find_join_rel(Query *root, Relids relids)
*/
RelOptInfo *
build_join_rel(Query *root,
List *joinrelids,
RelOptInfo *outer_rel,
RelOptInfo *inner_rel,
JoinType jointype,
List **restrictlist_ptr)
{
List *joinrelids;
RelOptInfo *joinrel;
List *restrictlist;
List *new_outer_tlist;
List *new_inner_tlist;
/* We should never try to join two overlapping sets of rels. */
Assert(nonoverlap_setsi(outer_rel->relids, inner_rel->relids));
/*
* See if we already have a joinrel for this set of base rels.
*
* nconc(listCopy(x), y) is an idiom for making a new list without
* changing either input list.
*/
joinrelids = nconc(listCopy(outer_rel->relids), inner_rel->relids);
joinrel = find_join_rel(root, joinrelids);
if (joinrel)
@ -299,13 +294,14 @@ build_join_rel(Query *root,
*/
joinrel = makeNode(RelOptInfo);
joinrel->reloptkind = RELOPT_JOINREL;
joinrel->relids = joinrelids;
joinrel->relids = listCopy(joinrelids);
joinrel->rows = 0;
joinrel->width = 0;
joinrel->targetlist = NIL;
joinrel->pathlist = NIL;
joinrel->cheapest_startup_path = NULL;
joinrel->cheapest_total_path = NULL;
joinrel->cheapest_unique_path = NULL;
joinrel->pruneable = true;
joinrel->rtekind = RTE_JOIN;
joinrel->indexlist = NIL;
@ -557,7 +553,7 @@ subbuild_joinrel_joinlist(RelOptInfo *joinrel,
*/
JoinInfo *new_joininfo;
new_joininfo = find_joininfo_node(joinrel, new_unjoined_relids);
new_joininfo = make_joininfo_node(joinrel, new_unjoined_relids);
new_joininfo->jinfo_restrictinfo =
set_union(new_joininfo->jinfo_restrictinfo,
joininfo->jinfo_restrictinfo);