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Make flatten_join_alias_vars() do the right thing when expanding an alias

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referenced from a subquery.  Per example from Stefanos Harhalakis.
This commit is contained in:
Tom Lane
2003-02-06 22:21:11 +00:00
parent 77ede8900d
commit 00f1a41ab2
1 changed files with 14 additions and 2 deletions
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16
src/backend/optimizer/util/var.c
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@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.47 2003/01/20 18:54:58 tgl Exp $ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.48 2003/02/06 22:21:11 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -19,6 +19,7 @@
#include "optimizer/prep.h" #include "optimizer/prep.h"
#include "optimizer/var.h" #include "optimizer/var.h"
#include "parser/parsetree.h" #include "parser/parsetree.h"
#include "rewrite/rewriteManip.h"
typedef struct typedef struct
@ -400,14 +401,25 @@ flatten_join_alias_vars_mutator(Node *node,
RangeTblEntry *rte; RangeTblEntry *rte;
Node *newvar; Node *newvar;
/* No change unless Var belongs to a JOIN of the target level */
if (var->varlevelsup != context->sublevels_up) if (var->varlevelsup != context->sublevels_up)
return node; /* no need to copy, really */ return node; /* no need to copy, really */
rte = rt_fetch(var->varno, context->root->rtable); rte = rt_fetch(var->varno, context->root->rtable);
if (rte->rtekind != RTE_JOIN) if (rte->rtekind != RTE_JOIN)
return node; return node;
Assert(var->varattno > 0); Assert(var->varattno > 0);
/* Okay, must expand it */
newvar = (Node *) nth(var->varattno - 1, rte->joinaliasvars); newvar = (Node *) nth(var->varattno - 1, rte->joinaliasvars);
/* expand it; recurse in case join input is itself a join */ /*
* If we are expanding an alias carried down from an upper query,
* must adjust its varlevelsup fields.
*/
if (context->sublevels_up != 0)
{
newvar = copyObject(newvar);
IncrementVarSublevelsUp(newvar, context->sublevels_up, 0);
}
/* Recurse in case join input is itself a join */
return flatten_join_alias_vars_mutator(newvar, context); return flatten_join_alias_vars_mutator(newvar, context);
} }
if (IsA(node, InClauseInfo)) if (IsA(node, InClauseInfo))