diff options
Diffstat (limited to 'src/backend/optimizer/util/restrictinfo.c')
| -rw-r--r-- | src/backend/optimizer/util/restrictinfo.c | 67 |
1 files changed, 33 insertions, 34 deletions
diff --git a/src/backend/optimizer/util/restrictinfo.c b/src/backend/optimizer/util/restrictinfo.c index 47b90aef46a..d277cac7351 100644 --- a/src/backend/optimizer/util/restrictinfo.c +++ b/src/backend/optimizer/util/restrictinfo.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.40 2005/10/13 00:06:46 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.41 2005/10/15 02:49:21 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -51,8 +51,8 @@ RestrictInfo * make_restrictinfo(Expr *clause, bool is_pushed_down, Relids required_relids) { /* - * If it's an OR clause, build a modified copy with RestrictInfos - * inserted above each subclause of the top-level AND/OR structure. + * If it's an OR clause, build a modified copy with RestrictInfos inserted + * above each subclause of the top-level AND/OR structure. */ if (or_clause((Node *) clause)) return (RestrictInfo *) make_sub_restrictinfos(clause, is_pushed_down); @@ -101,9 +101,9 @@ make_restrictinfo_from_bitmapqual(Path *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. + * 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) @@ -125,7 +125,7 @@ make_restrictinfo_from_bitmapqual(Path *bitmapqual, /* * 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 + * 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 @@ -142,8 +142,8 @@ make_restrictinfo_from_bitmapqual(Path *bitmapqual, { /* * 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. + * TRUE, and hence the OR result is also constant TRUE, so we + * can stop here. */ return NIL; } @@ -157,8 +157,8 @@ make_restrictinfo_from_bitmapqual(Path *bitmapqual, } /* - * Avoid generating one-element ORs, which could happen - * due to redundancy elimination. + * Avoid generating one-element ORs, which could happen due to + * redundancy elimination. */ if (list_length(withris) <= 1) result = withris; @@ -174,20 +174,20 @@ make_restrictinfo_from_bitmapqual(Path *bitmapqual, } else if (IsA(bitmapqual, IndexPath)) { - IndexPath *ipath = (IndexPath *) bitmapqual; + 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); + 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. + * 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, @@ -223,8 +223,8 @@ make_restrictinfo_internal(Expr *clause, Expr *orclause, restrictinfo->can_join = false; /* may get set below */ /* - * If it's a binary opclause, set up left/right relids info. In any - * case set up the total clause relids info. + * If it's a binary opclause, set up left/right relids info. In any case + * set up the total clause relids info. */ if (is_opclause(clause) && list_length(((OpExpr *) clause)->args) == 2) { @@ -232,13 +232,13 @@ make_restrictinfo_internal(Expr *clause, Expr *orclause, restrictinfo->right_relids = pull_varnos(get_rightop(clause)); restrictinfo->clause_relids = bms_union(restrictinfo->left_relids, - restrictinfo->right_relids); + restrictinfo->right_relids); /* * Does it look like a normal join clause, i.e., a binary operator - * relating expressions that come from distinct relations? If so - * we might be able to use it in a join algorithm. Note that this - * is a purely syntactic test that is made regardless of context. + * relating expressions that come from distinct relations? If so we + * might be able to use it in a join algorithm. Note that this is a + * purely syntactic test that is made regardless of context. */ if (!bms_is_empty(restrictinfo->left_relids) && !bms_is_empty(restrictinfo->right_relids) && @@ -262,11 +262,11 @@ make_restrictinfo_internal(Expr *clause, Expr *orclause, restrictinfo->required_relids = restrictinfo->clause_relids; /* - * Fill in all the cacheable fields with "not yet set" markers. None - * of these will be computed until/unless needed. Note in particular - * that we don't mark a binary opclause as mergejoinable or - * hashjoinable here; that happens only if it appears in the right - * context (top level of a joinclause list). + * Fill in all the cacheable fields with "not yet set" markers. None of + * these will be computed until/unless needed. Note in particular that we + * don't mark a binary opclause as mergejoinable or hashjoinable here; + * that happens only if it appears in the right context (top level of a + * joinclause list). */ restrictinfo->eval_cost.startup = -1; restrictinfo->this_selec = -1; @@ -420,17 +420,16 @@ remove_redundant_join_clauses(PlannerInfo *root, List *restrictinfo_list, QualCost cost; /* - * If there are any redundant clauses, we want to eliminate the ones - * that are more expensive in favor of the ones that are less so. Run + * If there are any redundant clauses, we want to eliminate the ones that + * are more expensive in favor of the ones that are less so. Run * cost_qual_eval() to ensure the eval_cost fields are set up. */ cost_qual_eval(&cost, restrictinfo_list); /* - * We don't have enough knowledge yet to be able to estimate the - * number of times a clause might be evaluated, so it's hard to weight - * the startup and per-tuple costs appropriately. For now just weight - * 'em the same. + * We don't have enough knowledge yet to be able to estimate the number of + * times a clause might be evaluated, so it's hard to weight the startup + * and per-tuple costs appropriately. For now just weight 'em the same. */ #define CLAUSECOST(r) ((r)->eval_cost.startup + (r)->eval_cost.per_tuple) |