diff options
Diffstat (limited to 'src/backend/optimizer/util/relnode.c')
| -rw-r--r-- | src/backend/optimizer/util/relnode.c | 75 |
1 files changed, 32 insertions, 43 deletions
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c index fbaf0de83a8..d66796d5cce 100644 --- a/src/backend/optimizer/util/relnode.c +++ b/src/backend/optimizer/util/relnode.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.69 2005/06/08 23:02:05 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.70 2005/06/09 04:19:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -479,8 +479,8 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel, * * These routines are separate because the restriction list must be * built afresh for each pair of input sub-relations we consider, whereas - * the join lists need only be computed once for any join RelOptInfo. - * The join lists are fully determined by the set of rels making up the + * the join list need only be computed once for any join RelOptInfo. + * The join list is fully determined by the set of rels making up the * joinrel, so we should get the same results (up to ordering) from any * candidate pair of sub-relations. But the restriction list is whatever * is not handled in the sub-relations, so it depends on which @@ -488,7 +488,7 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel, * * If a join clause from an input relation refers to base rels still not * present in the joinrel, then it is still a join clause for the joinrel; - * we put it into an appropriate JoinInfo list for the joinrel. Otherwise, + * we put it into the joininfo list for the joinrel. Otherwise, * the clause is now a restrict clause for the joined relation, and we * return it to the caller of build_joinrel_restrictlist() to be stored in * join paths made from this pair of sub-relations. (It will not need to @@ -506,7 +506,7 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel, * * build_joinrel_restrictlist() returns a list of relevant restrictinfos, * whereas build_joinrel_joinlist() stores its results in the joinrel's - * joininfo lists. One or the other must accept each given clause! + * joininfo list. One or the other must accept each given clause! * * NB: Formerly, we made deep(!) copies of each input RestrictInfo to pass * up to the join relation. I believe this is no longer necessary, because @@ -562,29 +562,27 @@ subbuild_joinrel_restrictlist(RelOptInfo *joinrel, List *joininfo_list) { List *restrictlist = NIL; - ListCell *xjoininfo; + ListCell *l; - foreach(xjoininfo, joininfo_list) + foreach(l, joininfo_list) { - JoinInfo *joininfo = (JoinInfo *) lfirst(xjoininfo); + RestrictInfo *rinfo = (RestrictInfo *) lfirst(l); - if (bms_is_subset(joininfo->unjoined_relids, joinrel->relids)) + if (bms_is_subset(rinfo->required_relids, joinrel->relids)) { /* - * Clauses in this JoinInfo list become restriction clauses - * for the joinrel, since they refer to no outside rels. - * - * We must copy the list to avoid disturbing the input relation, - * but we can use a shallow copy. + * This clause becomes a restriction clause for the joinrel, + * since it refers to no outside rels. We don't bother to + * check for duplicates here --- build_joinrel_restrictlist + * will do that. */ - restrictlist = list_concat(restrictlist, - list_copy(joininfo->jinfo_restrictinfo)); + restrictlist = lappend(restrictlist, rinfo); } else { /* - * These clauses are still join clauses at this level, so we - * ignore them in this routine. + * This clause is still a join clause at this level, so we + * ignore it in this routine. */ } } @@ -596,42 +594,33 @@ static void subbuild_joinrel_joinlist(RelOptInfo *joinrel, List *joininfo_list) { - ListCell *xjoininfo; + ListCell *l; - foreach(xjoininfo, joininfo_list) + foreach(l, joininfo_list) { - JoinInfo *joininfo = (JoinInfo *) lfirst(xjoininfo); - Relids new_unjoined_relids; + RestrictInfo *rinfo = (RestrictInfo *) lfirst(l); - new_unjoined_relids = bms_difference(joininfo->unjoined_relids, - joinrel->relids); - if (bms_is_empty(new_unjoined_relids)) + if (bms_is_subset(rinfo->required_relids, joinrel->relids)) { /* - * Clauses in this JoinInfo list become restriction clauses - * for the joinrel, since they refer to no outside rels. So we - * can ignore them in this routine. + * This clause becomes a restriction clause for the joinrel, + * since it refers to no outside rels. So we can ignore it + * in this routine. */ - bms_free(new_unjoined_relids); } else { /* - * These clauses are still join clauses at this level, so find - * or make the appropriate JoinInfo item for the joinrel, and - * add the clauses to it, eliminating duplicates. (Since - * RestrictInfo nodes are normally multiply-linked rather than - * copied, pointer equality should be a sufficient test. If - * two equal() nodes should happen to sneak in, no great harm - * is done --- they'll be detected by redundant-clause testing - * when they reach a restriction list.) + * This clause is still a join clause at this level, so add + * it to the joininfo list for the joinrel, being careful to + * eliminate duplicates. (Since RestrictInfo nodes are normally + * multiply-linked rather than copied, pointer equality should be + * a sufficient test. If two equal() nodes should happen to sneak + * in, no great harm is done --- they'll be detected by + * redundant-clause testing when they reach a restriction list.) */ - JoinInfo *new_joininfo; - - new_joininfo = make_joininfo_node(joinrel, new_unjoined_relids); - new_joininfo->jinfo_restrictinfo = - list_union_ptr(new_joininfo->jinfo_restrictinfo, - joininfo->jinfo_restrictinfo); + if (!list_member_ptr(joinrel->joininfo, rinfo)) + joinrel->joininfo = lappend(joinrel->joininfo, rinfo); } } } |