diff options
Diffstat (limited to 'src/backend/optimizer/util/restrictinfo.c')
| -rw-r--r-- | src/backend/optimizer/util/restrictinfo.c | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/src/backend/optimizer/util/restrictinfo.c b/src/backend/optimizer/util/restrictinfo.c index 55ce9d86543..d500154f5d8 100644 --- a/src/backend/optimizer/util/restrictinfo.c +++ b/src/backend/optimizer/util/restrictinfo.c @@ -15,7 +15,6 @@ #include "postgres.h" #include "optimizer/clauses.h" -#include "optimizer/predtest.h" #include "optimizer/restrictinfo.h" #include "optimizer/var.h" @@ -88,192 +87,6 @@ make_restrictinfo(Expr *clause, } /* - * make_restrictinfo_from_bitmapqual - * - * Given the bitmapqual Path structure for a bitmap indexscan, generate - * RestrictInfo node(s) equivalent to the condition represented by the - * indexclauses of the Path structure. - * - * The result is a List (effectively, implicit-AND representation) of - * RestrictInfos. - * - * The caller must pass is_pushed_down, but we assume outerjoin_delayed - * and pseudoconstant are false while outer_relids and nullable_relids - * are NULL (no other kind of qual should ever get into a bitmapqual). - * - * If include_predicates is true, we add any partial index predicates to - * the explicit index quals. When this is not true, we return a condition - * that might be weaker than the actual scan represents. - * - * To do this through the normal make_restrictinfo() API, callers would have - * to strip off the RestrictInfo nodes present in the indexclauses lists, and - * then make_restrictinfo() would have to build new ones. It's better to have - * a specialized routine to allow sharing of RestrictInfos. - * - * The qual manipulations here are much the same as in create_bitmap_subplan; - * keep the two routines in sync! - */ -List * -make_restrictinfo_from_bitmapqual(Path *bitmapqual, - bool is_pushed_down, - bool include_predicates) -{ - List *result; - ListCell *l; - - if (IsA(bitmapqual, BitmapAndPath)) - { - BitmapAndPath *apath = (BitmapAndPath *) bitmapqual; - - /* - * There may well be redundant quals among the subplans, since a - * top-level WHERE qual might have gotten used to form several - * different index quals. We don't try exceedingly hard to eliminate - * redundancies, but we do eliminate obvious duplicates by using - * list_concat_unique. - */ - result = NIL; - foreach(l, apath->bitmapquals) - { - List *sublist; - - sublist = make_restrictinfo_from_bitmapqual((Path *) lfirst(l), - is_pushed_down, - include_predicates); - result = list_concat_unique(result, sublist); - } - } - else if (IsA(bitmapqual, BitmapOrPath)) - { - BitmapOrPath *opath = (BitmapOrPath *) bitmapqual; - List *withris = NIL; - List *withoutris = NIL; - - /* - * Here, we only detect qual-free subplans. A qual-free subplan would - * cause us to generate "... OR true ..." which we may as well reduce - * to just "true". We do not try to eliminate redundant subclauses - * because (a) it's not as likely as in the AND case, and (b) we might - * well be working with hundreds or even thousands of OR conditions, - * perhaps from a long IN list. The performance of list_append_unique - * would be unacceptable. - */ - foreach(l, opath->bitmapquals) - { - List *sublist; - - sublist = make_restrictinfo_from_bitmapqual((Path *) lfirst(l), - is_pushed_down, - include_predicates); - if (sublist == NIL) - { - /* - * If we find a qual-less subscan, it represents a constant - * TRUE, and hence the OR result is also constant TRUE, so we - * can stop here. - */ - return NIL; - } - - /* - * If the sublist contains multiple RestrictInfos, we create an - * AND subclause. If there's just one, we have to check if it's - * an OR clause, and if so flatten it to preserve AND/OR flatness - * of our output. - * - * We construct lists with and without sub-RestrictInfos, so as - * not to have to regenerate duplicate RestrictInfos below. - */ - if (list_length(sublist) > 1) - { - withris = lappend(withris, make_andclause(sublist)); - sublist = get_actual_clauses(sublist); - withoutris = lappend(withoutris, make_andclause(sublist)); - } - else - { - RestrictInfo *subri = (RestrictInfo *) linitial(sublist); - - Assert(IsA(subri, RestrictInfo)); - if (restriction_is_or_clause(subri)) - { - BoolExpr *subor = (BoolExpr *) subri->orclause; - - Assert(or_clause((Node *) subor)); - withris = list_concat(withris, - list_copy(subor->args)); - subor = (BoolExpr *) subri->clause; - Assert(or_clause((Node *) subor)); - withoutris = list_concat(withoutris, - list_copy(subor->args)); - } - else - { - withris = lappend(withris, subri); - withoutris = lappend(withoutris, subri->clause); - } - } - } - - /* - * Avoid generating one-element ORs, which could happen due to - * redundancy elimination or ScalarArrayOpExpr quals. - */ - if (list_length(withris) <= 1) - result = withris; - else - { - /* Here's the magic part not available to outside callers */ - result = - list_make1(make_restrictinfo_internal(make_orclause(withoutris), - make_orclause(withris), - is_pushed_down, - false, - false, - NULL, - NULL, - NULL)); - } - } - else if (IsA(bitmapqual, IndexPath)) - { - IndexPath *ipath = (IndexPath *) bitmapqual; - - result = list_copy(ipath->indexclauses); - if (include_predicates && ipath->indexinfo->indpred != NIL) - { - foreach(l, ipath->indexinfo->indpred) - { - Expr *pred = (Expr *) lfirst(l); - - /* - * We know that the index predicate must have been implied by - * the query condition as a whole, but it may or may not be - * implied by the conditions that got pushed into the - * bitmapqual. Avoid generating redundant conditions. - */ - if (!predicate_implied_by(list_make1(pred), result)) - result = lappend(result, - make_restrictinfo(pred, - is_pushed_down, - false, - false, - NULL, - NULL, - NULL)); - } - } - } - else - { - elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual)); - result = NIL; /* keep compiler quiet */ - } - - return result; -} - -/* * make_restrictinfos_from_actual_clauses * * Given a list of implicitly-ANDed restriction clauses, produce a list |