diff options
Diffstat (limited to 'src/backend/optimizer/plan/initsplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/initsplan.c | 74 |
1 files changed, 26 insertions, 48 deletions
diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c index ef219245aab..7316a794612 100644 --- a/src/backend/optimizer/plan/initsplan.c +++ b/src/backend/optimizer/plan/initsplan.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.40 1999/10/07 04:23:06 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.41 2000/01/09 00:26:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -30,6 +30,7 @@ static void add_restrict_and_join_to_rel(Query *root, Node *clause); static void add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo, Relids join_relids); static void add_vars_to_targetlist(Query *root, List *vars); +static void set_restrictinfo_joininfo(RestrictInfo *restrictinfo); static void check_mergejoinable(RestrictInfo *restrictinfo); static void check_hashjoinable(RestrictInfo *restrictinfo); @@ -165,12 +166,6 @@ add_restrict_and_join_to_rel(Query *root, Node *clause) restrictinfo->hashjoinoperator = InvalidOid; /* - * The selectivity of the clause must be computed regardless of - * whether it's a restriction or a join clause - */ - restrictinfo->selectivity = compute_clause_selec(root, clause); - - /* * Retrieve all relids and vars contained within the clause. */ clause_get_relids_vars(clause, &relids, &vars); @@ -189,12 +184,20 @@ add_restrict_and_join_to_rel(Query *root, Node *clause) { /* * 'clause' is a join clause, since there is more than one atom in - * the relid list. Add it to the join lists of all the relevant + * the relid list. Set additional RestrictInfo fields for joining. + */ + set_restrictinfo_joininfo(restrictinfo); + /* + * Add clause to the join lists of all the relevant * relations. (If, perchance, 'clause' contains NO vars, then * nothing will happen...) */ add_join_info_to_rels(root, restrictinfo, relids); - /* we are going to be doing a join, so add vars to targetlists */ + /* + * Add vars used in the join clause to targetlists of member relations, + * so that they will be emitted by the plan nodes that scan those + * relations (else they won't be available at the join node!). + */ add_vars_to_targetlist(root, vars); } } @@ -202,7 +205,7 @@ add_restrict_and_join_to_rel(Query *root, Node *clause) /* * add_join_info_to_rels * For every relation participating in a join clause, add 'restrictinfo' to - * the appropriate joininfo list (creating a new one and adding it to the + * the appropriate joininfo list (creating a new list and adding it to the * appropriate rel node if necessary). * * 'restrictinfo' describes the join clause @@ -218,8 +221,8 @@ add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo, foreach(join_relid, join_relids) { int cur_relid = lfirsti(join_relid); - JoinInfo *joininfo; Relids unjoined_relids = NIL; + JoinInfo *joininfo; List *otherrel; /* Get the relids not equal to the current relid */ @@ -230,18 +233,12 @@ add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo, } /* - * Find or make the joininfo node for this combination of rels + * Find or make the joininfo node for this combination of rels, + * and add the restrictinfo node to it. */ joininfo = find_joininfo_node(get_base_rel(root, cur_relid), unjoined_relids); - - /* - * And add the restrictinfo node to it. NOTE that each joininfo - * gets its own copy of the restrictinfo node! (Is this really - * necessary? Possibly ... later parts of the optimizer destructively - * modify restrict/join clauses...) - */ - joininfo->jinfo_restrictinfo = lcons(copyObject((void *) restrictinfo), + joininfo->jinfo_restrictinfo = lcons(restrictinfo, joininfo->jinfo_restrictinfo); } } @@ -253,36 +250,17 @@ add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo, *****************************************************************************/ /* - * set_joininfo_mergeable_hashable - * Examine each join clause used in a query and set the merge and hash - * info fields in those that are mergejoinable or hashjoinable. + * set_restrictinfo_joininfo + * Examine a RestrictInfo that has been determined to be a join clause, + * and set the merge and hash info fields if it can be merge/hash joined. */ -void -set_joininfo_mergeable_hashable(List *rel_list) +static void +set_restrictinfo_joininfo(RestrictInfo *restrictinfo) { - List *x; - - foreach(x, rel_list) - { - RelOptInfo *rel = (RelOptInfo *) lfirst(x); - List *y; - - foreach(y, rel->joininfo) - { - JoinInfo *joininfo = (JoinInfo *) lfirst(y); - List *z; - - foreach(z, joininfo->jinfo_restrictinfo) - { - RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(z); - - if (_enable_mergejoin_) - check_mergejoinable(restrictinfo); - if (_enable_hashjoin_) - check_hashjoinable(restrictinfo); - } - } - } + if (_enable_mergejoin_) + check_mergejoinable(restrictinfo); + if (_enable_hashjoin_) + check_hashjoinable(restrictinfo); } /* |