diff options
Diffstat (limited to 'src/backend/optimizer/path/indxpath.c')
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 191 |
1 files changed, 101 insertions, 90 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index fa19abe4717..67238b5361c 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.145 2003/07/25 00:01:06 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.146 2003/08/04 00:43:20 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -64,9 +64,9 @@ static List *group_clauses_by_indexkey_for_join(Query *root, Relids outer_relids, JoinType jointype, bool isouterjoin); static bool match_clause_to_indexcol(RelOptInfo *rel, IndexOptInfo *index, - int indexcol, Oid opclass, Expr *clause); -static bool match_join_clause_to_indexcol(RelOptInfo *rel, IndexOptInfo *index, int indexcol, Oid opclass, Expr *clause); +static bool match_join_clause_to_indexcol(RelOptInfo *rel, IndexOptInfo *index, + int indexcol, Oid opclass, Expr *clause); static Oid indexable_operator(Expr *clause, Oid opclass, bool indexkey_on_left); static bool pred_test(List *predicate_list, List *restrictinfo_list, @@ -77,8 +77,8 @@ static bool pred_test_recurse_pred(Expr *predicate, Node *clause); static bool pred_test_simple_clause(Expr *predicate, Node *clause); static Relids indexable_outerrelids(RelOptInfo *rel, IndexOptInfo *index); static Path *make_innerjoin_index_path(Query *root, - RelOptInfo *rel, IndexOptInfo *index, - List *clausegroups); + RelOptInfo *rel, IndexOptInfo *index, + List *clausegroups); static bool match_index_to_operand(Node *operand, int indexcol, RelOptInfo *rel, IndexOptInfo *index); static bool match_special_index_operator(Expr *clause, Oid opclass, @@ -87,7 +87,7 @@ static List *expand_indexqual_condition(Expr *clause, Oid opclass); static List *prefix_quals(Node *leftop, Oid opclass, Const *prefix, Pattern_Prefix_Status pstatus); static List *network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, - Datum rightop); + Datum rightop); static Datum string_to_datum(const char *str, Oid datatype); static Const *string_to_const(const char *str, Oid datatype); @@ -114,7 +114,7 @@ static Const *string_to_const(const char *str, Oid datatype); * scan this routine deems potentially interesting for the current query. * * We also determine the set of other relids that participate in join - * clauses that could be used with each index. The actually best innerjoin + * clauses that could be used with each index. The actually best innerjoin * path will be generated for each outer relation later on, but knowing the * set of potential otherrels allows us to identify equivalent outer relations * and avoid repeated computation. @@ -219,10 +219,11 @@ create_index_paths(Query *root, RelOptInfo *rel) /* * 6. Examine join clauses to see which ones are potentially - * usable with this index, and generate the set of all other relids - * that participate in such join clauses. We'll use this set later - * to recognize outer rels that are equivalent for joining purposes. - * We compute both per-index and overall-for-relation sets. + * usable with this index, and generate the set of all other + * relids that participate in such join clauses. We'll use this + * set later to recognize outer rels that are equivalent for + * joining purposes. We compute both per-index and + * overall-for-relation sets. */ join_outerrelids = indexable_outerrelids(rel, index); index->outer_relids = join_outerrelids; @@ -274,7 +275,7 @@ match_index_orclauses(RelOptInfo *rel, */ restrictinfo->subclauseindices = match_index_orclause(rel, index, - ((BoolExpr *) restrictinfo->clause)->args, + ((BoolExpr *) restrictinfo->clause)->args, restrictinfo->subclauseindices); } } @@ -422,6 +423,7 @@ extract_or_indexqual_conditions(RelOptInfo *rel, Oid *classes = index->classlist; FastListInit(&quals); + /* * Extract relevant indexclauses in indexkey order. This is * essentially just like group_clauses_by_indexkey() except that the @@ -576,7 +578,7 @@ group_clauses_by_indexkey(RelOptInfo *rel, IndexOptInfo *index) * * This is much like group_clauses_by_indexkey(), but we consider both * join and restriction clauses. Any joinclause that uses only otherrels - * in the specified outer_relids is fair game. But there must be at least + * in the specified outer_relids is fair game. But there must be at least * one such joinclause in the final list, otherwise we return NIL indicating * that this index isn't interesting as an inner indexscan. (A scan using * only restriction clauses shouldn't be created here, because a regular Path @@ -641,10 +643,10 @@ group_clauses_by_indexkey_for_join(Query *root, */ if (FastListValue(&clausegroup) != NIL) { - List *nl; + List *nl; nl = remove_redundant_join_clauses(root, - FastListValue(&clausegroup), + FastListValue(&clausegroup), jointype); FastListFromList(&clausegroup, nl); } @@ -736,9 +738,9 @@ match_clause_to_indexcol(RelOptInfo *rel, return false; /* - * Check for clauses of the form: - * (indexkey operator constant) or (constant operator indexkey). - * Anything that is a "pseudo constant" expression will do. + * Check for clauses of the form: (indexkey operator constant) or + * (constant operator indexkey). Anything that is a "pseudo constant" + * expression will do. */ if (match_index_to_operand(leftop, indexcol, rel, index) && is_pseudo_constant_clause(rightop)) @@ -747,8 +749,8 @@ match_clause_to_indexcol(RelOptInfo *rel, return true; /* - * If we didn't find a member of the index's opclass, see - * whether it is a "special" indexable operator. + * If we didn't find a member of the index's opclass, see whether + * it is a "special" indexable operator. */ if (match_special_index_operator(clause, opclass, true)) return true; @@ -762,8 +764,8 @@ match_clause_to_indexcol(RelOptInfo *rel, return true; /* - * If we didn't find a member of the index's opclass, see - * whether it is a "special" indexable operator. + * If we didn't find a member of the index's opclass, see whether + * it is a "special" indexable operator. */ if (match_special_index_operator(clause, opclass, false)) return true; @@ -824,10 +826,10 @@ match_join_clause_to_indexcol(RelOptInfo *rel, return false; /* - * Check for an indexqual that could be handled by a nestloop - * join. We need the index key to be compared against an - * expression that uses none of the indexed relation's vars and - * contains no volatile functions. + * Check for an indexqual that could be handled by a nestloop join. We + * need the index key to be compared against an expression that uses + * none of the indexed relation's vars and contains no volatile + * functions. */ if (match_index_to_operand(leftop, indexcol, rel, index)) { @@ -1174,10 +1176,11 @@ pred_test_simple_clause(Expr *predicate, Node *clause) * 1. Find "btree" strategy numbers for the pred_op and clause_op. * * We must find a btree opclass that contains both operators, else the - * implication can't be determined. If there are multiple such opclasses, - * assume we can use any one to determine the logical relationship of the - * two operators and the correct corresponding test operator. This should - * work for any logically consistent opclasses. + * implication can't be determined. If there are multiple such + * opclasses, assume we can use any one to determine the logical + * relationship of the two operators and the correct corresponding + * test operator. This should work for any logically consistent + * opclasses. */ catlist = SearchSysCacheList(AMOPOPID, 1, ObjectIdGetDatum(pred_op), @@ -1269,7 +1272,7 @@ pred_test_simple_clause(Expr *predicate, Node *clause) /* And execute it. */ test_result = ExecEvalExprSwitchContext(test_exprstate, - GetPerTupleExprContext(estate), + GetPerTupleExprContext(estate), &isNull, NULL); /* Get back to outer memory context */ @@ -1295,7 +1298,7 @@ pred_test_simple_clause(Expr *predicate, Node *clause) /* * indexable_outerrelids * Finds all other relids that participate in any indexable join clause - * for the specified index. Returns a set of relids. + * for the specified index. Returns a set of relids. * * 'rel' is the relation for which 'index' is defined */ @@ -1314,16 +1317,16 @@ indexable_outerrelids(RelOptInfo *rel, IndexOptInfo *index) /* * Examine each joinclause in the JoinInfo node's list to see if * it matches any key of the index. If so, add the JoinInfo's - * otherrels to the result. We can skip examining other joinclauses - * in the same list as soon as we find a match (since by definition - * they all have the same otherrels). + * otherrels to the result. We can skip examining other + * joinclauses in the same list as soon as we find a match (since + * by definition they all have the same otherrels). */ foreach(j, joininfo->jinfo_restrictinfo) { RestrictInfo *rinfo = (RestrictInfo *) lfirst(j); - Expr *clause = rinfo->clause; - int indexcol = 0; - Oid *classes = index->classlist; + Expr *clause = rinfo->clause; + int indexcol = 0; + Oid *classes = index->classlist; do { @@ -1398,11 +1401,13 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, default: return NULL; } + /* * If there are no indexable joinclauses for this rel, exit quickly. */ if (bms_is_empty(rel->index_outer_relids)) return NULL; + /* * Otherwise, we have to do path selection in the memory context of * the given rel, so that any created path can be safely attached to @@ -1410,10 +1415,11 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, * issue for normal planning, but it is an issue for GEQO planning.) */ oldcontext = MemoryContextSwitchTo(GetMemoryChunkContext(rel)); + /* - * Intersect the given outer_relids with index_outer_relids - * to find the set of outer relids actually relevant for this index. - * If there are none, again we can fail immediately. + * Intersect the given outer_relids with index_outer_relids to find + * the set of outer relids actually relevant for this index. If there + * are none, again we can fail immediately. */ outer_relids = bms_intersect(rel->index_outer_relids, outer_relids); if (bms_is_empty(outer_relids)) @@ -1422,11 +1428,13 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, MemoryContextSwitchTo(oldcontext); return NULL; } + /* * Look to see if we already computed the result for this set of - * relevant outerrels. (We include the isouterjoin status in the + * relevant outerrels. (We include the isouterjoin status in the * cache lookup key for safety. In practice I suspect this is not - * necessary because it should always be the same for a given innerrel.) + * necessary because it should always be the same for a given + * innerrel.) */ foreach(jlist, rel->index_inner_paths) { @@ -1441,15 +1449,15 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, } /* - * For each index of the rel, find the best path; then choose the - * best overall. We cache the per-index results as well as the overall - * result. (This is useful because different indexes may have different - * relevant outerrel sets, so different overall outerrel sets might still - * map to the same computation for a given index.) + * For each index of the rel, find the best path; then choose the best + * overall. We cache the per-index results as well as the overall + * result. (This is useful because different indexes may have + * different relevant outerrel sets, so different overall outerrel + * sets might still map to the same computation for a given index.) */ foreach(ilist, rel->indexlist) { - IndexOptInfo *index = (IndexOptInfo *) lfirst(ilist); + IndexOptInfo *index = (IndexOptInfo *) lfirst(ilist); Relids index_outer_relids; Path *path = NULL; @@ -1461,6 +1469,7 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, bms_free(index_outer_relids); continue; } + /* * Look to see if we already computed the result for this index. */ @@ -1471,7 +1480,7 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, info->isouterjoin == isouterjoin) { path = info->best_innerpath; - bms_free(index_outer_relids); /* not needed anymore */ + bms_free(index_outer_relids); /* not needed anymore */ break; } } @@ -1484,9 +1493,9 @@ best_inner_indexscan(Query *root, RelOptInfo *rel, clausegroups = group_clauses_by_indexkey_for_join(root, rel, index, - index_outer_relids, + index_outer_relids, jointype, - isouterjoin); + isouterjoin); if (clausegroups) { /* make the path */ @@ -1548,9 +1557,9 @@ make_innerjoin_index_path(Query *root, pathnode->path.parent = rel; /* - * There's no point in marking the path with any pathkeys, since - * it will only ever be used as the inner path of a nestloop, and - * so its ordering does not matter. + * There's no point in marking the path with any pathkeys, since it + * will only ever be used as the inner path of a nestloop, and so its + * ordering does not matter. */ pathnode->path.pathkeys = NIL; @@ -1582,19 +1591,19 @@ make_innerjoin_index_path(Query *root, /* * We must compute the estimated number of output rows for the - * indexscan. This is less than rel->rows because of the - * additional selectivity of the join clauses. Since clausegroups - * may contain both restriction and join clauses, we have to do a - * set union to get the full set of clauses that must be - * considered to compute the correct selectivity. (Without the union - * operation, we might have some restriction clauses appearing twice, - * which'd mislead restrictlist_selectivity into double-counting their - * selectivity. However, since RestrictInfo nodes aren't copied when - * linking them into different lists, it should be sufficient to use - * pointer comparison to remove duplicates.) + * indexscan. This is less than rel->rows because of the additional + * selectivity of the join clauses. Since clausegroups may contain + * both restriction and join clauses, we have to do a set union to get + * the full set of clauses that must be considered to compute the + * correct selectivity. (Without the union operation, we might have + * some restriction clauses appearing twice, which'd mislead + * restrictlist_selectivity into double-counting their selectivity. + * However, since RestrictInfo nodes aren't copied when linking them + * into different lists, it should be sufficient to use pointer + * comparison to remove duplicates.) * - * Always assume the join type is JOIN_INNER; even if some of the - * join clauses come from other contexts, that's not our problem. + * Always assume the join type is JOIN_INNER; even if some of the join + * clauses come from other contexts, that's not our problem. */ allclauses = set_ptrUnion(rel->baserestrictinfo, allclauses); pathnode->rows = rel->tuples * @@ -1656,9 +1665,9 @@ match_index_to_operand(Node *operand, else { /* - * Index expression; find the correct expression. (This search could - * be avoided, at the cost of complicating all the callers of this - * routine; doesn't seem worth it.) + * Index expression; find the correct expression. (This search + * could be avoided, at the cost of complicating all the callers + * of this routine; doesn't seem worth it.) */ List *indexprs; int i; @@ -1677,6 +1686,7 @@ match_index_to_operand(Node *operand, if (indexprs == NIL) elog(ERROR, "wrong number of index expressions"); indexkey = (Node *) lfirst(indexprs); + /* * Does it match the operand? Again, strip any relabeling. */ @@ -1776,12 +1786,12 @@ match_special_index_operator(Expr *clause, Oid opclass, case OID_NAME_LIKE_OP: /* the right-hand const is type text for all of these */ isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Like, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; break; case OID_BYTEA_LIKE_OP: isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Like, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; break; case OID_TEXT_ICLIKE_OP: @@ -1789,7 +1799,7 @@ match_special_index_operator(Expr *clause, Oid opclass, case OID_NAME_ICLIKE_OP: /* the right-hand const is type text for all of these */ isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Like_IC, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; break; case OID_TEXT_REGEXEQ_OP: @@ -1797,7 +1807,7 @@ match_special_index_operator(Expr *clause, Oid opclass, case OID_NAME_REGEXEQ_OP: /* the right-hand const is type text for all of these */ isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Regex, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; break; case OID_TEXT_ICREGEXEQ_OP: @@ -1805,7 +1815,7 @@ match_special_index_operator(Expr *clause, Oid opclass, case OID_NAME_ICREGEXEQ_OP: /* the right-hand const is type text for all of these */ isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Regex_IC, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; break; case OID_INET_SUB_OP: @@ -1831,9 +1841,9 @@ match_special_index_operator(Expr *clause, Oid opclass, * want to apply. (A hash index, for example, will not support ">=".) * Currently, only btree supports the operators we need. * - * We insist on the opclass being the specific one we expect, - * else we'd do the wrong thing if someone were to make a reverse-sort - * opclass with the same operators. + * We insist on the opclass being the specific one we expect, else we'd + * do the wrong thing if someone were to make a reverse-sort opclass + * with the same operators. */ switch (expr_op) { @@ -1896,7 +1906,7 @@ match_special_index_operator(Expr *clause, Oid opclass, * The input list is ordered by index key, and so the output list is too. * (The latter is not depended on by any part of the planner, so far as I can * tell; but some parts of the executor do assume that the indxqual list - * ultimately delivered to the executor is so ordered. One such place is + * ultimately delivered to the executor is so ordered. One such place is * _bt_orderkeys() in the btree support. Perhaps that ought to be fixed * someday --- tgl 7/00) */ @@ -1930,7 +1940,7 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups) } while (clausegroups != NIL && !DoneMatchingIndexKeys(classes)); - Assert(clausegroups == NIL); /* else more groups than indexkeys... */ + Assert(clausegroups == NIL); /* else more groups than indexkeys... */ return FastListValue(&resultquals); } @@ -1953,11 +1963,12 @@ expand_indexqual_condition(Expr *clause, Oid opclass) switch (expr_op) { - /* - * LIKE and regex operators are not members of any index - * opclass, so if we find one in an indexqual list we can - * assume that it was accepted by match_special_index_operator(). - */ + /* + * LIKE and regex operators are not members of any index + * opclass, so if we find one in an indexqual list we can + * assume that it was accepted by + * match_special_index_operator(). + */ case OID_TEXT_LIKE_OP: case OID_BPCHAR_LIKE_OP: case OID_NAME_LIKE_OP: @@ -2061,22 +2072,22 @@ prefix_quals(Node *leftop, Oid opclass, } /* - * If necessary, coerce the prefix constant to the right type. - * The given prefix constant is either text or bytea type. + * If necessary, coerce the prefix constant to the right type. The + * given prefix constant is either text or bytea type. */ if (prefix_const->consttype != datatype) { - char *prefix; + char *prefix; switch (prefix_const->consttype) { case TEXTOID: prefix = DatumGetCString(DirectFunctionCall1(textout, - prefix_const->constvalue)); + prefix_const->constvalue)); break; case BYTEAOID: prefix = DatumGetCString(DirectFunctionCall1(byteaout, - prefix_const->constvalue)); + prefix_const->constvalue)); break; default: elog(ERROR, "unexpected const type: %u", |