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First cut at making indexscan cost estimates depend on correlation

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between index order and table order.
This commit is contained in:
Tom Lane
2001-05-09 23:13:37 +00:00
parent e02033572d
commit c23bc6fbb0
8 changed files with 317 additions and 88 deletions
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57
src/backend/optimizer/util/var.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.31 2001/04/18 20:42:55 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.32 2001/05/09 23:13:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -28,8 +28,9 @@ typedef struct
typedef struct
{
int varno;
int varattno;
int sublevels_up;
} contain_whole_tuple_var_context;
} contain_var_reference_context;
typedef struct
{
@@ -39,8 +40,8 @@ typedef struct
static bool pull_varnos_walker(Node *node,
pull_varnos_context *context);
static bool contain_whole_tuple_var_walker(Node *node,
contain_whole_tuple_var_context *context);
static bool contain_var_reference_walker(Node *node,
contain_var_reference_context *context);
static bool contain_var_clause_walker(Node *node, void *context);
static bool pull_var_clause_walker(Node *node,
pull_var_clause_context *context);
@@ -129,10 +130,10 @@ pull_varnos_walker(Node *node, pull_varnos_context *context)
/*
* contain_whole_tuple_var
* contain_var_reference
*
* Detect whether a parsetree contains any references to the whole
* tuple of a given rtable entry (ie, a Var with varattno = 0).
* Detect whether a parsetree contains any references to a specified
* attribute of a specified rtable entry.
*
* NOTE: this is used on not-yet-planned expressions. It may therefore find
* bare SubLinks, and if so it needs to recurse into them to look for uplevel
@@ -140,11 +141,12 @@ pull_varnos_walker(Node *node, pull_varnos_context *context)
* SubPlan, we only need to look at the parameters passed to the subplan.
*/
bool
contain_whole_tuple_var(Node *node, int varno, int levelsup)
contain_var_reference(Node *node, int varno, int varattno, int levelsup)
{
contain_whole_tuple_var_context context;
contain_var_reference_context context;
context.varno = varno;
context.varattno = varattno;
context.sublevels_up = levelsup;
/*
@@ -154,15 +156,15 @@ contain_whole_tuple_var(Node *node, int varno, int levelsup)
*/
if (node && IsA(node, Query))
return query_tree_walker((Query *) node,
contain_whole_tuple_var_walker,
contain_var_reference_walker,
(void *) &context, true);
else
return contain_whole_tuple_var_walker(node, &context);
return contain_var_reference_walker(node, &context);
}
static bool
contain_whole_tuple_var_walker(Node *node,
contain_whole_tuple_var_context *context)
contain_var_reference_walker(Node *node,
contain_var_reference_context *context)
{
if (node == NULL)
return false;
@@ -171,8 +173,8 @@ contain_whole_tuple_var_walker(Node *node,
Var *var = (Var *) node;
if (var->varno == context->varno &&
var->varlevelsup == context->sublevels_up &&
var->varattno == InvalidAttrNumber)
var->varattno == context->varattno &&
var->varlevelsup == context->sublevels_up)
return true;
return false;
}
@@ -187,11 +189,11 @@ contain_whole_tuple_var_walker(Node *node,
*/
Expr *expr = (Expr *) node;
if (contain_whole_tuple_var_walker((Node *) ((SubPlan *) expr->oper)->sublink->oper,
context))
if (contain_var_reference_walker((Node *) ((SubPlan *) expr->oper)->sublink->oper,
context))
return true;
if (contain_whole_tuple_var_walker((Node *) expr->args,
context))
if (contain_var_reference_walker((Node *) expr->args,
context))
return true;
return false;
}
@@ -202,16 +204,29 @@ contain_whole_tuple_var_walker(Node *node,
context->sublevels_up++;
result = query_tree_walker((Query *) node,
contain_whole_tuple_var_walker,
contain_var_reference_walker,
(void *) context, true);
context->sublevels_up--;
return result;
}
return expression_tree_walker(node, contain_whole_tuple_var_walker,
return expression_tree_walker(node, contain_var_reference_walker,
(void *) context);
}
/*
* contain_whole_tuple_var
*
* Detect whether a parsetree contains any references to the whole
* tuple of a given rtable entry (ie, a Var with varattno = 0).
*/
bool
contain_whole_tuple_var(Node *node, int varno, int levelsup)
{
return contain_var_reference(node, varno, InvalidAttrNumber, levelsup);
}
/*
* contain_var_clause
* Recursively scan a clause to discover whether it contains any Var nodes