The following bug has been logged on the website:
Bug reference: 6693
Logged by: Ken Cheung
Email address: msrbugzilla@gmail.com
PostgreSQL version: 9.1.3
Operating system: Linux
Description:=20=20=20=20=20=20=20=20
I observed a code clone in the following files. In these functions,
qry->resultRelation is computed differently but the comment above mentions
the same functionality. I wonder if this is a bug. Hope it helps.
function : ChangeVarNodes @ (file:
"postgresql-9.1.3/src/backend/rewrite/rewriteManip.c", line: 570)~608
context.rt_index =3D rt_index;
context.new_index =3D new_index;
context.sublevels_up =3D sublevels_up;
/*
* Must be prepared to start with a Query or a bare expression tree; if
* it's a Query, go straight to query_tree_walker to make sure that
* sublevels_up doesn't get incremented prematurely.
*/
if (node && IsA(node, Query))
{
Query *qry =3D (Query *) node;
/*
* If we are starting at a Query, and sublevels_up is zero, then we
* must also fix rangetable indexes in the Query itself --- namely
* resultRelation and rowMarks entries. sublevels_up cannot be zero
* when recursing into a subquery, so there's no need to have the same
* logic inside ChangeVarNodes_walker.
*/
if (sublevels_up =3D=3D 0)
{
ListCell *l;
if (qry->resultRelation =3D=3D rt_index)
qry->resultRelation =3D new_index;
foreach(l, qry->rowMarks)
{
RowMarkClause *rc =3D (RowMarkClause *) lfirst(l);
if (rc->rti =3D=3D rt_index)
rc->rti =3D new_index;
}
}
query_tree_walker(qry, ChangeVarNodes_walker,
(void *) &context, 0);
}
else
ChangeVarNodes_walker(node, &context);
function : OffsetVarNodes @ (file:
"postgresql-9.1.3/src/backend/rewrite/rewriteManip.c", line: 402)~438
context.offset =3D offset;
context.sublevels_up =3D sublevels_up;
/*
* Must be prepared to start with a Query or a bare expression tree; if
* it's a Query, go straight to query_tree_walker to make sure that
* sublevels_up doesn't get incremented prematurely.
*/
if (node && IsA(node, Query))
{
Query *qry =3D (Query *) node;
/*
* If we are starting at a Query, and sublevels_up is zero, then we
* must also fix rangetable indexes in the Query itself --- namely
* resultRelation and rowMarks entries. sublevels_up cannot be zero
* when recursing into a subquery, so there's no need to have the same
* logic inside OffsetVarNodes_walker.
*/
if (sublevels_up =3D=3D 0)
{
ListCell *l;
if (qry->resultRelation)
qry->resultRelation +=3D offset;
foreach(l, qry->rowMarks)
{
RowMarkClause *rc =3D (RowMarkClause *) lfirst(l);
rc->rti +=3D offset;
}
}
query_tree_walker(qry, OffsetVarNodes_walker,
(void *) &context, 0);
}
else
OffsetVarNodes_walker(node, &context);