Outer Join Query Over Dblink Can Fail With ORA-904 (Doc ID 730256.1)

In this Document

APPLIES TO:

SYMPTOMS

Following query over dblink having Local database 9iR2 and remote
10gR2 works..

select *
from [email protected]
i,
[email protected] s,ods.institutions oi
where
s.stt_state_type_id (+) = i.stt_state_type_id
and oi.ctps_insttn_id =
i.inst_insttn_id
and i.inst_modifd_dt = trunc(sysdate)
and (nvl
(oi.inst_state_txt, ‘x‘) <> nvl (s.stt_state_type_nm, ‘x‘))
and
(nvl (oi.inst_phone_txt, 17) <> nvl (i.inst_phone_txt,
17));

The same query fails when both local and remote databases are
10g R2, with following errors:

ERROR at line 2:
ORA-00904:
"OI"."INST_STATE_TXT": invalid identifier
ORA-02063: preceding line
from CTPS3

CHANGES

CAUSE

Outer join query over dblink can fail with ORA-904, as referenced
in:

BUG
6620988 QUERY OVER
DBLINK FAILS WITH ORA-904 SELECTING DATE

Predicates are not checked
to verify if they belong to same network node when we attempt to colocate
the remote tables. This results in wrongly generating remote query and
ORA-904

REDISCOVERY INFORMATION:
1. ORA-904
2. DB link
3.
OJ predicates across network nodes
4. predicates wrongly pushed network
nodes

SOLUTION

-- To implement the solution, please execute the following
steps::

Use the workaround of disabling colocated joins via event
10176 and force a hard parse to happen
(ie by flushing the shared
pool), ie:

SQL> alter session set events ‘10176 trace name
context forever‘;
SQL> alter system flush
shared_pool;

or

For a permanent fix, request a One-Off
Backport of 6620988 for the appropiate platform.

REFERENCES