On 2016/02/10 4:16, Robert Haas wrote:
On Tue, Feb 9, 2016 at 8:39 AM, Ashutosh Bapat
<ashutosh.ba...@enterprisedb.com> wrote:
Thanks Jeevan for your review and comments. PFA the patch which fixes those.
Committed with a couple more small adjustments.
Thanks for working on this, Robert, Ashutosh, and everyone involved!
I happened to notice that this code in foreign_join_ok():
switch (jointype)
{
case JOIN_INNER:
fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
fpinfo_i->remote_conds);
fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
fpinfo_o->remote_conds);
break;
case JOIN_LEFT:
fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
fpinfo_i->remote_conds);
fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
fpinfo_o->remote_conds);
break;
case JOIN_RIGHT:
fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
fpinfo_o->remote_conds);
fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
fpinfo_i->remote_conds);
break;
case JOIN_FULL:
fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
fpinfo_i->remote_conds);
fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
fpinfo_o->remote_conds);
break;
default:
/* Should not happen, we have just check this above */
elog(ERROR, "unsupported join type %d", jointype);
}
would break the list fpinfo_i->remote_conds in the case of INNER JOIN or
FULL JOIN. You can see the list breakage from e.g., the following
queries on an Assert-enabled build:
postgres=# create extension postgres_fdw;
CREATE EXTENSION
postgres=# create server myserver foreign data wrapper postgres_fdw
options (dbname 'mydatabase');
CREATE SERVER
postgres=# create user mapping for current_user server myserver;
CREATE USER MAPPING
postgres=# create foreign table foo (a int) server myserver options
(table_name 'foo');
CREATE FOREIGN TABLE
postgres=# create foreign table bar (a int) server myserver options
(table_name 'bar');
CREATE FOREIGN TABLE
postgres=# create foreign table baz (a int) server myserver options
(table_name 'baz');
CREATE FOREIGN TABLE
postgres=# select * from foo, bar, baz where foo.a = bar.a and bar.a =
baz.a and foo.a < 10 and bar.a < 10 and baz.a < 10;
Attached is a patch to avoid the breakage.
Best regards,
Etsuro Fujita
*** a/contrib/postgres_fdw/postgres_fdw.c
--- b/contrib/postgres_fdw/postgres_fdw.c
***************
*** 3488,3495 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
case JOIN_INNER:
fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
fpinfo_i->remote_conds);
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
! fpinfo_o->remote_conds);
break;
case JOIN_LEFT:
--- 3488,3496 ----
case JOIN_INNER:
fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
fpinfo_i->remote_conds);
! if (fpinfo_o->remote_conds)
! fpinfo->remote_conds = list_concat(list_copy(fpinfo->remote_conds),
! fpinfo_o->remote_conds);
break;
case JOIN_LEFT:
***************
*** 3509,3516 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
case JOIN_FULL:
fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
fpinfo_i->remote_conds);
! fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
! fpinfo_o->remote_conds);
break;
default:
--- 3510,3518 ----
case JOIN_FULL:
fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
fpinfo_i->remote_conds);
! if (fpinfo_o->remote_conds)
! fpinfo->joinclauses = list_concat(list_copy(fpinfo->joinclauses),
! fpinfo_o->remote_conds);
break;
default:
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