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Suppress subquery pullup and pushdown when the subquery has any

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set-returning functions in its target list.  This ensures that we
won't rewrite the query in a way that places set-returning functions
into quals (WHERE clauses).  Cf. bug reports from Joe Conway.
This commit is contained in:
Tom Lane
2001-12-10 22:54:12 +00:00
parent 584f818bef
commit 63cc56de54
4 changed files with 59 additions and 6 deletions
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36
src/backend/optimizer/util/clauses.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.91 2001/11/05 17:46:26 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.92 2001/12/10 22:54:12 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -47,6 +47,7 @@ typedef struct
static bool contain_agg_clause_walker(Node *node, void *context);
static bool pull_agg_clause_walker(Node *node, List **listptr);
static bool contain_iter_clause_walker(Node *node, void *context);
static bool contain_subplans_walker(Node *node, void *context);
static bool pull_subplans_walker(Node *node, List **listptr);
static bool check_subplans_for_ungrouped_vars_walker(Node *node,
@@ -450,6 +451,39 @@ pull_agg_clause_walker(Node *node, List **listptr)
}
/*****************************************************************************
* Iter clause manipulation
*****************************************************************************/
/*
* contain_iter_clause
* Recursively search for Iter nodes within a clause.
*
* Returns true if any Iter found.
*
* XXX Iter is a crock. It'd be better to look directly at each function
* or operator to see if it can return a set. However, that would require
* a lot of extra cycles as things presently stand. The return-type info
* for function and operator nodes should be extended to include whether
* the return is a set.
*/
bool
contain_iter_clause(Node *clause)
{
return contain_iter_clause_walker(clause, NULL);
}
static bool
contain_iter_clause_walker(Node *node, void *context)
{
if (node == NULL)
return false;
if (IsA(node, Iter))
return true; /* abort the tree traversal and return
* true */
return expression_tree_walker(node, contain_iter_clause_walker, context);
}
/*****************************************************************************
* Subplan clause manipulation
*****************************************************************************/