From 5f68d5c38f7a66546b0770eeb1c30927f7765e0f Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 31 Dec 1999 03:41:03 +0000
Subject: [PATCH] Clean up loose end in LIKE optimization fix: parser's code
would generate <= and >= indexquals from a LIKE even if the index in question
didn't support those operators. (As, for example, a hash index does not.)
---
src/backend/optimizer/path/indxpath.c | 169 ++++++++++++++++++--------
1 file changed, 115 insertions(+), 54 deletions(-)
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 4f52f9377d2..1e9154edb95 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.73 1999/11/22 17:56:07 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.74 1999/12/31 03:41:03 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -44,24 +44,30 @@ typedef enum {
Prefix_None, Prefix_Partial, Prefix_Exact
} Prefix_Status;
-static void match_index_orclauses(RelOptInfo *rel, RelOptInfo *index, int indexkey,
- int xclass, List *restrictinfo_list);
-static List *match_index_orclause(RelOptInfo *rel, RelOptInfo *index, int indexkey,
- int xclass, List *or_clauses, List *other_matching_indices);
+static void match_index_orclauses(RelOptInfo *rel, RelOptInfo *index,
+ int indexkey, Oid opclass,
+ List *restrictinfo_list);
+static List *match_index_orclause(RelOptInfo *rel, RelOptInfo *index,
+ int indexkey, Oid opclass,
+ List *or_clauses,
+ List *other_matching_indices);
static bool match_or_subclause_to_indexkey(RelOptInfo *rel, RelOptInfo *index,
- int indexkey, int xclass,
+ int indexkey, Oid opclass,
Expr *clause);
static List *group_clauses_by_indexkey(RelOptInfo *rel, RelOptInfo *index,
- int *indexkeys, Oid *classes, List *restrictinfo_list);
+ int *indexkeys, Oid *classes,
+ List *restrictinfo_list);
static List *group_clauses_by_ikey_for_joins(RelOptInfo *rel, RelOptInfo *index,
- int *indexkeys, Oid *classes, List *join_cinfo_list, List *restr_cinfo_list);
+ int *indexkeys, Oid *classes,
+ List *join_cinfo_list,
+ List *restr_cinfo_list);
static bool match_clause_to_indexkey(RelOptInfo *rel, RelOptInfo *index,
- int indexkey, int xclass,
+ int indexkey, Oid opclass,
Expr *clause, bool join);
-static bool indexable_operator(Expr *clause, int xclass, Oid relam,
+static bool indexable_operator(Expr *clause, Oid opclass, Oid relam,
bool indexkey_on_left);
static bool pred_test(List *predicate_list, List *restrictinfo_list,
- List *joininfo_list);
+ List *joininfo_list);
static bool one_pred_test(Expr *predicate, List *restrictinfo_list);
static bool one_pred_clause_expr_test(Expr *predicate, Node *clause);
static bool one_pred_clause_test(Expr *predicate, Node *clause);
@@ -77,13 +83,16 @@ static bool useful_for_ordering(Query *root, RelOptInfo *rel,
RelOptInfo *index);
static bool match_index_to_operand(int indexkey, Var *operand,
RelOptInfo *rel, RelOptInfo *index);
-static bool function_index_operand(Expr *funcOpnd, RelOptInfo *rel, RelOptInfo *index);
-static bool match_special_index_operator(Expr *clause, bool indexkey_on_left);
+static bool function_index_operand(Expr *funcOpnd, RelOptInfo *rel,
+ RelOptInfo *index);
+static bool match_special_index_operator(Expr *clause, Oid opclass, Oid relam,
+ bool indexkey_on_left);
static Prefix_Status like_fixed_prefix(char *patt, char **prefix);
static Prefix_Status regex_fixed_prefix(char *patt, bool case_insensitive,
char **prefix);
static List *prefix_quals(Var *leftop, Oid expr_op,
char *prefix, Prefix_Status pstatus);
+static Oid find_operator(const char * opname, Oid datatype);
/*
@@ -255,7 +264,7 @@ static void
match_index_orclauses(RelOptInfo *rel,
RelOptInfo *index,
int indexkey,
- int xclass,
+ Oid opclass,
List *restrictinfo_list)
{
List *i;
@@ -272,7 +281,7 @@ match_index_orclauses(RelOptInfo *rel,
*/
restrictinfo->subclauseindices =
match_index_orclause(rel, index,
- indexkey, xclass,
+ indexkey, opclass,
restrictinfo->clause->args,
restrictinfo->subclauseindices);
}
@@ -304,7 +313,7 @@ static List *
match_index_orclause(RelOptInfo *rel,
RelOptInfo *index,
int indexkey,
- int xclass,
+ Oid opclass,
List *or_clauses,
List *other_matching_indices)
{
@@ -330,7 +339,7 @@ match_index_orclause(RelOptInfo *rel,
{
Expr *clause = lfirst(clist);
- if (match_or_subclause_to_indexkey(rel, index, indexkey, xclass,
+ if (match_or_subclause_to_indexkey(rel, index, indexkey, opclass,
clause))
{
/* OK to add this index to sublist for this subclause */
@@ -355,7 +364,7 @@ static bool
match_or_subclause_to_indexkey(RelOptInfo *rel,
RelOptInfo *index,
int indexkey,
- int xclass,
+ Oid opclass,
Expr *clause)
{
if (and_clause((Node *) clause))
@@ -364,14 +373,14 @@ match_or_subclause_to_indexkey(RelOptInfo *rel,
foreach(item, clause->args)
{
- if (! match_clause_to_indexkey(rel, index, indexkey, xclass,
+ if (! match_clause_to_indexkey(rel, index, indexkey, opclass,
lfirst(item), false))
return false;
}
return true;
}
else
- return match_clause_to_indexkey(rel, index, indexkey, xclass,
+ return match_clause_to_indexkey(rel, index, indexkey, opclass,
clause, false);
}
@@ -588,7 +597,7 @@ group_clauses_by_ikey_for_joins(RelOptInfo *rel,
* 'rel' is the relation of interest.
* 'index' is an index on 'rel'.
* 'indexkey' is a key of 'index'.
- * 'xclass' is the corresponding operator class.
+ * 'opclass' is the corresponding operator class.
* 'clause' is the clause to be tested.
* 'join' is true if we are considering this clause for joins.
*
@@ -601,7 +610,7 @@ static bool
match_clause_to_indexkey(RelOptInfo *rel,
RelOptInfo *index,
int indexkey,
- int xclass,
+ Oid opclass,
Expr *clause,
bool join)
{
@@ -627,26 +636,28 @@ match_clause_to_indexkey(RelOptInfo *rel,
if ((IsA(rightop, Const) || IsA(rightop, Param)) &&
match_index_to_operand(indexkey, leftop, rel, index))
{
- if (indexable_operator(clause, xclass, index->relam, true))
+ if (indexable_operator(clause, opclass, index->relam, true))
return true;
/*
* 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, true))
+ if (match_special_index_operator(clause, opclass, index->relam,
+ true))
return true;
return false;
}
if ((IsA(leftop, Const) || IsA(leftop, Param)) &&
match_index_to_operand(indexkey, rightop, rel, index))
{
- if (indexable_operator(clause, xclass, index->relam, false))
+ if (indexable_operator(clause, opclass, index->relam, false))
return true;
/*
* 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, false))
+ if (match_special_index_operator(clause, opclass, index->relam,
+ false))
return true;
return false;
}
@@ -666,7 +677,7 @@ match_clause_to_indexkey(RelOptInfo *rel,
isIndexable = ! intMember(lfirsti(rel->relids), othervarnos);
freeList(othervarnos);
if (isIndexable &&
- indexable_operator(clause, xclass, index->relam, true))
+ indexable_operator(clause, opclass, index->relam, true))
return true;
}
else if (match_index_to_operand(indexkey, rightop, rel, index))
@@ -677,7 +688,7 @@ match_clause_to_indexkey(RelOptInfo *rel,
isIndexable = ! intMember(lfirsti(rel->relids), othervarnos);
freeList(othervarnos);
if (isIndexable &&
- indexable_operator(clause, xclass, index->relam, false))
+ indexable_operator(clause, opclass, index->relam, false))
return true;
}
}
@@ -706,7 +717,7 @@ match_clause_to_indexkey(RelOptInfo *rel,
* a tad ugly...
*/
static bool
-indexable_operator(Expr *clause, int xclass, Oid relam,
+indexable_operator(Expr *clause, Oid opclass, Oid relam,
bool indexkey_on_left)
{
Oid expr_op = ((Oper *) clause->oper)->opno;
@@ -723,7 +734,7 @@ indexable_operator(Expr *clause, int xclass, Oid relam,
return false;
/* Done if the (commuted) operator is a member of the index's AM */
- if (op_class(commuted_op, xclass, relam))
+ if (op_class(commuted_op, opclass, relam))
return true;
/*
@@ -766,7 +777,7 @@ indexable_operator(Expr *clause, int xclass, Oid relam,
if (commuted_op == InvalidOid)
return false;
- if (op_class(commuted_op, xclass, relam))
+ if (op_class(commuted_op, opclass, relam))
{
/*
* Success! Change the opclause to use the
@@ -1561,7 +1572,8 @@ function_index_operand(Expr *funcOpnd, RelOptInfo *rel, RelOptInfo *index)
* Return 'true' if we can do something with it anyway.
*/
static bool
-match_special_index_operator(Expr *clause, bool indexkey_on_left)
+match_special_index_operator(Expr *clause, Oid opclass, Oid relam,
+ bool indexkey_on_left)
{
bool isIndexable = false;
Var *leftop,
@@ -1625,6 +1637,51 @@ match_special_index_operator(Expr *clause, bool indexkey_on_left)
break;
}
+ /* done if the expression doesn't look indexable */
+ if (! isIndexable)
+ return false;
+
+ /*
+ * Must also check that index's opclass supports the operators we will
+ * want to apply. (A hash index, for example, will not support ">=".)
+ * We cheat a little by not checking for availability of "=" ... any
+ * index type should support "=", methinks.
+ */
+ switch (expr_op)
+ {
+ case OID_TEXT_LIKE_OP:
+ case OID_TEXT_REGEXEQ_OP:
+ case OID_TEXT_ICREGEXEQ_OP:
+ if (! op_class(find_operator(">=", TEXTOID), opclass, relam) ||
+ ! op_class(find_operator("<=", TEXTOID), opclass, relam))
+ isIndexable = false;
+ break;
+
+ case OID_BPCHAR_LIKE_OP:
+ case OID_BPCHAR_REGEXEQ_OP:
+ case OID_BPCHAR_ICREGEXEQ_OP:
+ if (! op_class(find_operator(">=", BPCHAROID), opclass, relam) ||
+ ! op_class(find_operator("<=", BPCHAROID), opclass, relam))
+ isIndexable = false;
+ break;
+
+ case OID_VARCHAR_LIKE_OP:
+ case OID_VARCHAR_REGEXEQ_OP:
+ case OID_VARCHAR_ICREGEXEQ_OP:
+ if (! op_class(find_operator(">=", VARCHAROID), opclass, relam) ||
+ ! op_class(find_operator("<=", VARCHAROID), opclass, relam))
+ isIndexable = false;
+ break;
+
+ case OID_NAME_LIKE_OP:
+ case OID_NAME_REGEXEQ_OP:
+ case OID_NAME_ICREGEXEQ_OP:
+ if (! op_class(find_operator(">=", NAMEOID), opclass, relam) ||
+ ! op_class(find_operator("<=", NAMEOID), opclass, relam))
+ isIndexable = false;
+ break;
+ }
+
return isIndexable;
}
@@ -1848,7 +1905,7 @@ prefix_quals(Var *leftop, Oid expr_op,
{
List *result;
Oid datatype;
- HeapTuple optup;
+ Oid oproid;
void *conval;
Const *con;
Oper *op;
@@ -1893,12 +1950,8 @@ prefix_quals(Var *leftop, Oid expr_op,
*/
if (pstatus == Prefix_Exact)
{
- optup = SearchSysCacheTuple(OPERNAME,
- PointerGetDatum("="),
- ObjectIdGetDatum(datatype),
- ObjectIdGetDatum(datatype),
- CharGetDatum('b'));
- if (!HeapTupleIsValid(optup))
+ oproid = find_operator("=", datatype);
+ if (oproid == InvalidOid)
elog(ERROR, "prefix_quals: no = operator for type %u", datatype);
/* Note: we cheat a little by assuming that textin() will do for
* bpchar and varchar constants too...
@@ -1908,7 +1961,7 @@ prefix_quals(Var *leftop, Oid expr_op,
con = makeConst(datatype, ((datatype == NAMEOID) ? NAMEDATALEN : -1),
PointerGetDatum(conval),
false, false, false, false);
- op = makeOper(optup->t_data->t_oid, InvalidOid, BOOLOID, 0, NULL);
+ op = makeOper(oproid, InvalidOid, BOOLOID, 0, NULL);
expr = make_opclause(op, leftop, (Var *) con);
result = lcons(expr, NIL);
return result;
@@ -1919,19 +1972,15 @@ prefix_quals(Var *leftop, Oid expr_op,
*
* We can always say "x >= prefix".
*/
- optup = SearchSysCacheTuple(OPERNAME,
- PointerGetDatum(">="),
- ObjectIdGetDatum(datatype),
- ObjectIdGetDatum(datatype),
- CharGetDatum('b'));
- if (!HeapTupleIsValid(optup))
+ oproid = find_operator(">=", datatype);
+ if (oproid == InvalidOid)
elog(ERROR, "prefix_quals: no >= operator for type %u", datatype);
conval = (datatype == NAMEOID) ?
(void*) namein(prefix) : (void*) textin(prefix);
con = makeConst(datatype, ((datatype == NAMEOID) ? NAMEDATALEN : -1),
PointerGetDatum(conval),
false, false, false, false);
- op = makeOper(optup->t_data->t_oid, InvalidOid, BOOLOID, 0, NULL);
+ op = makeOper(oproid, InvalidOid, BOOLOID, 0, NULL);
expr = make_opclause(op, leftop, (Var *) con);
result = lcons(expr, NIL);
@@ -1947,22 +1996,34 @@ prefix_quals(Var *leftop, Oid expr_op,
prefix[prefixlen] = '\377';
prefix[prefixlen+1] = '\0';
- optup = SearchSysCacheTuple(OPERNAME,
- PointerGetDatum("<="),
- ObjectIdGetDatum(datatype),
- ObjectIdGetDatum(datatype),
- CharGetDatum('b'));
- if (!HeapTupleIsValid(optup))
+ oproid = find_operator("<=", datatype);
+ if (oproid == InvalidOid)
elog(ERROR, "prefix_quals: no <= operator for type %u", datatype);
conval = (datatype == NAMEOID) ?
(void*) namein(prefix) : (void*) textin(prefix);
con = makeConst(datatype, ((datatype == NAMEOID) ? NAMEDATALEN : -1),
PointerGetDatum(conval),
false, false, false, false);
- op = makeOper(optup->t_data->t_oid, InvalidOid, BOOLOID, 0, NULL);
+ op = makeOper(oproid, InvalidOid, BOOLOID, 0, NULL);
expr = make_opclause(op, leftop, (Var *) con);
result = lappend(result, expr);
#endif
return result;
}
+
+/* See if there is a binary op of the given name for the given datatype */
+static Oid
+find_operator(const char * opname, Oid datatype)
+{
+ HeapTuple optup;
+
+ optup = SearchSysCacheTuple(OPERNAME,
+ PointerGetDatum(opname),
+ ObjectIdGetDatum(datatype),
+ ObjectIdGetDatum(datatype),
+ CharGetDatum('b'));
+ if (!HeapTupleIsValid(optup))
+ return InvalidOid;
+ return optup->t_data->t_oid;
+}
--
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