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Fix thinko in new logic about pushing down non-nullability constraints:

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constraints appearing in outer-join qualification clauses are restricted
as to when and where they can be pushed down.  Add regression test
to catch future errors in this area.
This commit is contained in:
Tom Lane
2003-02-10 17:08:50 +00:00
parent ec8f0e82ef
commit 8a4fdce9f2
3 changed files with 192 additions and 8 deletions
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38
src/backend/optimizer/prep/prepjointree.c
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@@ -16,7 +16,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.5 2003/02/09 23:57:19 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.6 2003/02/10 17:08:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -694,23 +694,45 @@ reduce_outer_joins_pass2(Node *jtnode,
/* Only recurse if there's more to do below here */
if (left_state->contains_outer || right_state->contains_outer)
{
Relids local_nonnullable;
Relids pass_nonnullable;
/*
* Scan join quals to see if we can add any nonnullability
* constraints. (Okay to do this even if join is still outer.)
* If this join is (now) inner, we can add any nonnullability
* constraints its quals provide to those we got from above.
* But if it is outer, we can only pass down the local constraints
* into the nullable side, because an outer join never eliminates
* any rows from its non-nullable side. If it's a FULL join then
* it doesn't eliminate anything from either side.
*/
pass_nonnullable = find_nonnullable_rels(j->quals, true);
pass_nonnullable = bms_add_members(pass_nonnullable,
nonnullable_rels);
/* And recurse as needed */
if (jointype != JOIN_FULL)
{
local_nonnullable = find_nonnullable_rels(j->quals, true);
local_nonnullable = bms_add_members(local_nonnullable,
nonnullable_rels);
}
else
local_nonnullable = NULL; /* no use in calculating it */
if (left_state->contains_outer)
{
if (jointype == JOIN_INNER || jointype == JOIN_RIGHT)
pass_nonnullable = local_nonnullable;
else
pass_nonnullable = nonnullable_rels;
reduce_outer_joins_pass2(j->larg, left_state, parse,
pass_nonnullable);
}
if (right_state->contains_outer)
{
if (jointype == JOIN_INNER || jointype == JOIN_LEFT)
pass_nonnullable = local_nonnullable;
else
pass_nonnullable = nonnullable_rels;
reduce_outer_joins_pass2(j->rarg, right_state, parse,
pass_nonnullable);
bms_free(pass_nonnullable);
}
bms_free(local_nonnullable);
}
}
else