diff options
Diffstat (limited to 'src/backend/optimizer/path/indxpath.c')
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 65 |
1 files changed, 35 insertions, 30 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index ed5a53db0b9..064a2fafa50 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 1.102 2001/02/16 03:16:57 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.103 2001/03/22 03:59:35 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -183,8 +183,8 @@ create_index_paths(Query *root, restrictinfo_list); /* - * 3. Compute pathkeys describing index's ordering, if any, - * then see how many of them are actually useful for this query. + * 3. Compute pathkeys describing index's ordering, if any, then + * see how many of them are actually useful for this query. */ index_pathkeys = build_index_pathkeys(root, rel, index, ForwardScanDirection); @@ -207,8 +207,9 @@ create_index_paths(Query *root, NoMovementScanDirection)); /* - * 5. If the index is ordered, a backwards scan might be interesting. - * Currently this is only possible for a DESC query result ordering. + * 5. If the index is ordered, a backwards scan might be + * interesting. Currently this is only possible for a DESC query + * result ordering. */ if (index_is_ordered) { @@ -422,10 +423,11 @@ extract_or_indexqual_conditions(RelOptInfo *rel, if (and_clause((Node *) orsubclause)) { + /* - * Extract relevant sub-subclauses in indexkey order. This is just - * like group_clauses_by_indexkey() except that the input and output - * are lists of bare clauses, not of RestrictInfo nodes. + * Extract relevant sub-subclauses in indexkey order. This is + * just like group_clauses_by_indexkey() except that the input and + * output are lists of bare clauses, not of RestrictInfo nodes. */ int *indexkeys = index->indexkeys; Oid *classes = index->classlist; @@ -446,8 +448,8 @@ extract_or_indexqual_conditions(RelOptInfo *rel, } /* - * If no clauses match this key, we're done; we don't want to look - * at keys to its right. + * If no clauses match this key, we're done; we don't want to + * look at keys to its right. */ if (clausegroup == NIL) break; @@ -748,8 +750,8 @@ match_clause_to_indexkey(RelOptInfo *rel, /* * 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 non-cachable functions. + * expression that uses none of the indexed relation's vars and + * contains no non-cachable functions. */ if (match_index_to_operand(indexkey, leftop, rel, index)) { @@ -793,7 +795,7 @@ match_clause_to_indexkey(RelOptInfo *rel, * recognizing binary-compatible datatypes. For example, if we have * an expression like "oid = 123", the operator will be oideqint4, * which we need to replace with oideq in order to recognize it as - * matching an oid_ops index on the oid field. A variant case is where + * matching an oid_ops index on the oid field. A variant case is where * the expression is like "oid::int4 = 123", where the given operator * will be int4eq and again we need to intuit that we want to use oideq. * @@ -832,13 +834,13 @@ indexable_operator(Expr *clause, Oid opclass, Oid relam, /* * Maybe the index uses a binary-compatible operator set. * - * Get the nominal input types of the given operator and the actual - * type (before binary-compatible relabeling) of the index key. + * Get the nominal input types of the given operator and the actual type + * (before binary-compatible relabeling) of the index key. */ oldoptup = SearchSysCache(OPEROID, ObjectIdGetDatum(expr_op), 0, 0, 0); - if (! HeapTupleIsValid(oldoptup)) + if (!HeapTupleIsValid(oldoptup)) return InvalidOid; /* probably can't happen */ oldopform = (Form_pg_operator) GETSTRUCT(oldoptup); opname = pstrdup(NameStr(oldopform->oprname)); @@ -848,7 +850,7 @@ indexable_operator(Expr *clause, Oid opclass, Oid relam, if (indexkey_on_left) { - Node *leftop = (Node *) get_leftop(clause); + Node *leftop = (Node *) get_leftop(clause); if (leftop && IsA(leftop, RelabelType)) leftop = ((RelabelType *) leftop)->arg; @@ -856,7 +858,7 @@ indexable_operator(Expr *clause, Oid opclass, Oid relam, } else { - Node *rightop = (Node *) get_rightop(clause); + Node *rightop = (Node *) get_rightop(clause); if (rightop && IsA(rightop, RelabelType)) rightop = ((RelabelType *) rightop)->arg; @@ -874,9 +876,10 @@ indexable_operator(Expr *clause, Oid opclass, Oid relam, return InvalidOid; /* - * OK, look for operator of the same name with the indexkey's data type. - * (In theory this might find a non-semantically-comparable operator, - * but in practice that seems pretty unlikely for binary-compatible types.) + * OK, look for operator of the same name with the indexkey's data + * type. (In theory this might find a non-semantically-comparable + * operator, but in practice that seems pretty unlikely for + * binary-compatible types.) */ new_op = compatible_oper_opid(opname, indexkeytype, indexkeytype, true); @@ -886,8 +889,8 @@ indexable_operator(Expr *clause, Oid opclass, Oid relam, { /* - * OK, we found a binary-compatible operator of the same - * name; now does it match the index? + * OK, we found a binary-compatible operator of the same name; + * now does it match the index? */ if (indexkey_on_left) commuted_op = new_op; @@ -1491,8 +1494,9 @@ match_index_to_operand(int indexkey, RelOptInfo *rel, IndexOptInfo *index) { + /* - * Ignore any RelabelType node above the indexkey. This is needed to + * Ignore any RelabelType node above the indexkey. This is needed to * be able to apply indexscanning in binary-compatible-operator cases. * Note: we can assume there is at most one RelabelType node; * eval_const_expressions() will have simplified if more than one. @@ -1670,7 +1674,7 @@ match_special_index_operator(Expr *clause, Oid opclass, Oid relam, patt = DatumGetCString(DirectFunctionCall1(textout, constvalue)); isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Like, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; if (prefix) pfree(prefix); pfree(patt); @@ -1687,7 +1691,7 @@ match_special_index_operator(Expr *clause, Oid opclass, Oid relam, patt = DatumGetCString(DirectFunctionCall1(textout, constvalue)); isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Like_IC, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; if (prefix) pfree(prefix); pfree(patt); @@ -1704,7 +1708,7 @@ match_special_index_operator(Expr *clause, Oid opclass, Oid relam, patt = DatumGetCString(DirectFunctionCall1(textout, constvalue)); isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Regex, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; if (prefix) pfree(prefix); pfree(patt); @@ -1721,7 +1725,7 @@ match_special_index_operator(Expr *clause, Oid opclass, Oid relam, patt = DatumGetCString(DirectFunctionCall1(textout, constvalue)); isIndexable = pattern_fixed_prefix(patt, Pattern_Type_Regex_IC, - &prefix, &rest) != Pattern_Prefix_None; + &prefix, &rest) != Pattern_Prefix_None; if (prefix) pfree(prefix); pfree(patt); @@ -1983,8 +1987,8 @@ prefix_quals(Var *leftop, Oid expr_op, result = makeList1(expr); /* - * If we can create a string larger than the prefix, we can say - * "x < greaterstr". + * If we can create a string larger than the prefix, we can say "x < + * greaterstr". */ greaterstr = make_greater_string(prefix, datatype); if (greaterstr) @@ -2025,6 +2029,7 @@ find_operator(const char *opname, Oid datatype) static Datum string_to_datum(const char *str, Oid datatype) { + /* * We cheat a little by assuming that textin() will do for bpchar and * varchar constants too... |