75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* nodeFuncs.c
|
|
* All node routines more complicated than simple access/modification
|
|
*
|
|
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* $PostgreSQL: pgsql/src/backend/nodes/nodeFuncs.c,v 1.28 2007/01/05 22:19:30 momjian Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include "nodes/nodeFuncs.h"
|
|
|
|
|
|
static bool var_is_inner(Var *var);
|
|
|
|
|
|
/*
|
|
* single_node -
|
|
* Returns t if node corresponds to a single-noded expression
|
|
*/
|
|
bool
|
|
single_node(Node *node)
|
|
{
|
|
if (IsA(node, Const) ||
|
|
IsA(node, Var) ||
|
|
IsA(node, Param))
|
|
return true;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* VAR nodes
|
|
*****************************************************************************/
|
|
|
|
/*
|
|
* var_is_outer
|
|
* var_is_inner
|
|
* var_is_mat
|
|
* var_is_rel
|
|
*
|
|
* Returns t iff the var node corresponds to (respectively):
|
|
* the outer relation in a join
|
|
* the inner relation of a join
|
|
* a materialized relation
|
|
* a base relation (i.e., not an attribute reference, a variable from
|
|
* some lower join level, or a sort result)
|
|
* var node is an array reference
|
|
*
|
|
*/
|
|
bool
|
|
var_is_outer(Var *var)
|
|
{
|
|
return (bool) (var->varno == OUTER);
|
|
}
|
|
|
|
static bool
|
|
var_is_inner(Var *var)
|
|
{
|
|
return (bool) (var->varno == INNER);
|
|
}
|
|
|
|
bool
|
|
var_is_rel(Var *var)
|
|
{
|
|
return (bool)
|
|
!(var_is_inner(var) || var_is_outer(var));
|
|
}
|