diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 62 |
1 files changed, 41 insertions, 21 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 1a0ff1ac209..19b1cfcaad4 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.138 2005/11/22 18:17:12 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.139 2005/12/20 02:30:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -51,6 +51,7 @@ static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte); static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte); +static RelOptInfo *make_rel_from_joinlist(PlannerInfo *root, List *joinlist); static RelOptInfo *make_one_rel_by_joins(PlannerInfo *root, int levels_needed, List *initial_rels); static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, @@ -73,7 +74,7 @@ static void recurse_push_qual(Node *setOp, Query *topquery, * single rel that represents the join of all base rels in the query. */ RelOptInfo * -make_one_rel(PlannerInfo *root) +make_one_rel(PlannerInfo *root, List *joinlist) { RelOptInfo *rel; @@ -85,10 +86,7 @@ make_one_rel(PlannerInfo *root) /* * Generate access paths for the entire join tree. */ - Assert(root->parse->jointree != NULL && - IsA(root->parse->jointree, FromExpr)); - - rel = make_fromexpr_rel(root, root->parse->jointree); + rel = make_rel_from_joinlist(root, joinlist); /* * The result should join all and only the query's base rels. @@ -528,43 +526,65 @@ set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) } /* - * make_fromexpr_rel - * Build access paths for a FromExpr jointree node. + * make_rel_from_joinlist + * Build access paths using a "joinlist" to guide the join path search. + * + * See comments for deconstruct_jointree() for definition of the joinlist + * data structure. */ -RelOptInfo * -make_fromexpr_rel(PlannerInfo *root, FromExpr *from) +static RelOptInfo * +make_rel_from_joinlist(PlannerInfo *root, List *joinlist) { int levels_needed; - List *initial_rels = NIL; - ListCell *jt; + List *initial_rels; + ListCell *jl; /* - * Count the number of child jointree nodes. This is the depth of the + * Count the number of child joinlist nodes. This is the depth of the * dynamic-programming algorithm we must employ to consider all ways of * joining the child nodes. */ - levels_needed = list_length(from->fromlist); + levels_needed = list_length(joinlist); if (levels_needed <= 0) return NULL; /* nothing to do? */ /* - * Construct a list of rels corresponding to the child jointree nodes. + * Construct a list of rels corresponding to the child joinlist nodes. * This may contain both base rels and rels constructed according to - * explicit JOIN directives. + * sub-joinlists. */ - foreach(jt, from->fromlist) + initial_rels = NIL; + foreach(jl, joinlist) { - Node *jtnode = (Node *) lfirst(jt); + Node *jlnode = (Node *) lfirst(jl); + RelOptInfo *thisrel; + + if (IsA(jlnode, RangeTblRef)) + { + int varno = ((RangeTblRef *) jlnode)->rtindex; + + thisrel = find_base_rel(root, varno); + } + else if (IsA(jlnode, List)) + { + /* Recurse to handle subproblem */ + thisrel = make_rel_from_joinlist(root, (List *) jlnode); + } + else + { + elog(ERROR, "unrecognized joinlist node type: %d", + (int) nodeTag(jlnode)); + thisrel = NULL; /* keep compiler quiet */ + } - initial_rels = lappend(initial_rels, - make_jointree_rel(root, jtnode)); + initial_rels = lappend(initial_rels, thisrel); } if (levels_needed == 1) { /* - * Single jointree node, so we're done. + * Single joinlist node, so we're done. */ return (RelOptInfo *) linitial(initial_rels); } |