Multiple schema and Query performance issue

From: <oracle-l-bounce_at_freelists.org>
Date: Thu, 12 Oct 2006 18:14:12 -0400
Message-ID: <D6424CD4C8A3C044BBC49877ED51C51801DBB11C@ex2003.metratech.com>

Hi,

In our application we have 1 main schema (schema1) and 3 other schema(schema2,schema3,schema4) in nologging mode for performance reasons. Now when I try to run the following query connected as schema1 that should take less than few ms:
SELECT col1,col2
FROM
Schema2.tmp_tab1

Optimizer run the following recursive query and that takes 3-4 sec: SELECT /*+ RULE */ COUNT(*)
FROM
ALL_SYNONYMS WHERE DB_LINK IS NOT NULL AND SYNONYM_NAME= 'TMP_tab1' AND OWNER='SCHEMA2'

Is this a normal behavior when running the query that uses table of another schema as 3-4 sec looks very high time and explain plan showing lot of access to internal tables.
What are the possible solutions to make sure that optimizer don't need to run the recursive query?

Thanks
--Harvinder

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http://www.freelists.org/webpage/oracle-l Received on Thu Oct 12 2006 - 17:14:12 CDT