1. We are using OBIEE 10.1.3.4
2. We have a request that generates a query in DB2 where the joins are all inner joins and the join conditions are simply specified in the WHERE clause.
3. I added an LTS to a logical table consisting of a left outer join. Everything works dandy.
4. Problem is that in the new SQL generated, the original join conditions are still in the WHERE clause, and the new outer join is specified with "LEFT OUTER JOIN" syntax. The performance was substantially impacted. Our DBA has determined that the problem is the mix of syntax. Once the SQL uses "LEFT OUTER JOIN", then the inner join conditions should not be in the WHERE clause, but rather should be specified using "INNER JOIN" syntax. She tested her theory, and indeed, the SQL runs fast.
5. Now the problem is how to get OBIEE to use "INNER JOIN" syntax?? I looked in the "Features" tab of the Database in the RPD, and I am not sure which parameter (if any) will do the trick.
Does anyone know which Parameter will help?
If not, do you have any suggestions to solve the performance problem?
Thanks a ton.
David