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Allow merge and hash joins to occur on arbitrary expressions (anything not

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containing a volatile function), rather than only on 'Var = Var' clauses
as before.  This makes it practical to do flatten_join_alias_vars at the
start of planning, which in turn eliminates a bunch of klugery inside the
planner to deal with alias vars.  As a free side effect, we now detect
implied equality of non-Var expressions; for example in
	SELECT ... WHERE a.x = b.y and b.y = 42
we will deduce a.x = 42 and use that as a restriction qual on a.  Also,
we can remove the restriction introduced 12/5/02 to prevent pullup of
subqueries whose targetlists contain sublinks.
Still TODO: make statistical estimation routines in selfuncs.c and costsize.c
smarter about expressions that are more complex than plain Vars.  The need
for this is considerably greater now that we have to be able to estimate
the suitability of merge and hash join techniques on such expressions.
This commit is contained in:
Tom Lane
2003-01-15 19:35:48 +00:00
parent 0eed62f34d
commit de97072e3c
32 changed files with 523 additions and 662 deletions
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42
src/backend/optimizer/path/indxpath.c
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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.130 2002/12/16 21:30:29 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.131 2003/01/15 19:35:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -85,15 +85,15 @@ static Relids indexable_outerrelids(RelOptInfo *rel, IndexOptInfo *index);
static Path *make_innerjoin_index_path(Query *root,
RelOptInfo *rel, IndexOptInfo *index,
List *clausegroup);
static bool match_index_to_operand(int indexkey, Var *operand,
static bool match_index_to_operand(int indexkey, Node *operand,
RelOptInfo *rel, IndexOptInfo *index);
static bool function_index_operand(Expr *funcOpnd, RelOptInfo *rel,
IndexOptInfo *index);
static bool match_special_index_operator(Expr *clause, Oid opclass,
bool indexkey_on_left);
static List *prefix_quals(Var *leftop, Oid expr_op,
static List *prefix_quals(Node *leftop, Oid expr_op,
Const *prefix, Pattern_Prefix_Status pstatus);
static List *network_prefix_quals(Var *leftop, Oid expr_op, Datum rightop);
static List *network_prefix_quals(Node *leftop, Oid expr_op, Datum rightop);
static Oid find_operator(const char *opname, Oid datatype);
static Datum string_to_datum(const char *str, Oid datatype);
static Const *string_to_const(const char *str, Oid datatype);
@ -713,7 +713,7 @@ match_clause_to_indexkey(RelOptInfo *rel,
Oid opclass,
Expr *clause)
{
Var *leftop,
Node *leftop,
*rightop;
/* Clause must be a binary opclause. */
@ -730,7 +730,7 @@ match_clause_to_indexkey(RelOptInfo *rel,
* Anything that is a "pseudo constant" expression will do.
*/
if (match_index_to_operand(indexkey, leftop, rel, index) &&
is_pseudo_constant_clause((Node *) rightop))
is_pseudo_constant_clause(rightop))
{
if (is_indexable_operator(clause, opclass, true))
return true;
@ -745,7 +745,7 @@ match_clause_to_indexkey(RelOptInfo *rel,
}
if (match_index_to_operand(indexkey, rightop, rel, index) &&
is_pseudo_constant_clause((Node *) leftop))
is_pseudo_constant_clause(leftop))
{
if (is_indexable_operator(clause, opclass, false))
return true;
@ -801,7 +801,7 @@ match_join_clause_to_indexkey(RelOptInfo *rel,
Oid opclass,
Expr *clause)
{
Var *leftop,
Node *leftop,
*rightop;
/* Clause must be a binary opclause. */
@ -820,12 +820,12 @@ match_join_clause_to_indexkey(RelOptInfo *rel,
*/
if (match_index_to_operand(indexkey, leftop, rel, index))
{
List *othervarnos = pull_varnos((Node *) rightop);
List *othervarnos = pull_varnos(rightop);
bool isIndexable;
isIndexable =
!intMember(lfirsti(rel->relids), othervarnos) &&
!contain_volatile_functions((Node *) rightop) &&
!contain_volatile_functions(rightop) &&
is_indexable_operator(clause, opclass, true);
freeList(othervarnos);
return isIndexable;
@ -833,12 +833,12 @@ match_join_clause_to_indexkey(RelOptInfo *rel,
if (match_index_to_operand(indexkey, rightop, rel, index))
{
List *othervarnos = pull_varnos((Node *) leftop);
List *othervarnos = pull_varnos(leftop);
bool isIndexable;
isIndexable =
!intMember(lfirsti(rel->relids), othervarnos) &&
!contain_volatile_functions((Node *) leftop) &&
!contain_volatile_functions(leftop) &&
is_indexable_operator(clause, opclass, false);
freeList(othervarnos);
return isIndexable;
@ -1622,7 +1622,7 @@ make_innerjoin_index_path(Query *root,
*/
static bool
match_index_to_operand(int indexkey,
Var *operand,
Node *operand,
RelOptInfo *rel,
IndexOptInfo *index)
{
@ -1633,7 +1633,7 @@ match_index_to_operand(int indexkey,
* eval_const_expressions() will have simplified if more than one.
*/
if (operand && IsA(operand, RelabelType))
operand = (Var *) ((RelabelType *) operand)->arg;
operand = (Node *) ((RelabelType *) operand)->arg;
if (index->indproc == InvalidOid)
{
@ -1641,8 +1641,8 @@ match_index_to_operand(int indexkey,
* Simple index.
*/
if (operand && IsA(operand, Var) &&
lfirsti(rel->relids) == operand->varno &&
indexkey == operand->varattno)
lfirsti(rel->relids) == ((Var *) operand)->varno &&
indexkey == ((Var *) operand)->varattno)
return true;
else
return false;
@ -1764,7 +1764,7 @@ match_special_index_operator(Expr *clause, Oid opclass,
bool indexkey_on_left)
{
bool isIndexable = false;
Var *leftop,
Node *leftop,
*rightop;
Oid expr_op;
Const *patt = NULL;
@ -1944,8 +1944,8 @@ expand_indexqual_conditions(List *indexquals)
Expr *clause = (Expr *) lfirst(q);
/* we know these will succeed */
Var *leftop = get_leftop(clause);
Var *rightop = get_rightop(clause);
Node *leftop = get_leftop(clause);
Node *rightop = get_rightop(clause);
Oid expr_op = ((OpExpr *) clause)->opno;
Const *patt = (Const *) rightop;
Const *prefix = NULL;
@ -2033,7 +2033,7 @@ expand_indexqual_conditions(List *indexquals)
* operators.
*/
static List *
prefix_quals(Var *leftop, Oid expr_op,
prefix_quals(Node *leftop, Oid expr_op,
Const *prefix_const, Pattern_Prefix_Status pstatus)
{
List *result;
@ -2143,7 +2143,7 @@ prefix_quals(Var *leftop, Oid expr_op,
* operator.
*/
static List *
network_prefix_quals(Var *leftop, Oid expr_op, Datum rightop)
network_prefix_quals(Node *leftop, Oid expr_op, Datum rightop)
{
bool is_eq;
char *opr1name;