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IBM Cognos 8 Platform => COGNOS 8 => Report Studio => Topic started by: dipstm on 26 Jun 2009 06:04:02 PM

Title: Cognos Generated SQL -- Partition by Clause
Post by: dipstm on 26 Jun 2009 06:04:02 PM
Hi All,

When i generate the Cognos SQL for a particular query I see that Cognos creates a Partition by clause in SQL.So if in my query i have aggregate functions , the Cognos generated SQL always contains a partition by clause. I feel this is impacting my  report performance. Is there any way to avoid Cognos creating a partition by clause.
If anyone has any suggestions plz let us know.

Thanx in Advance.
Title: Re: Cognos Generated SQL -- Partition by Clause
Post by: blom0344 on 29 Jun 2009 04:45:57 AM
I'd suggest running a trace on the SQL that is actually executed on the database. The question is whether the RDBMS optimizer will indeed use it. What Cognos suggests as generated SQL is certainly NOT always the executed path!!
Title: Re: Cognos Generated SQL -- Partition by Clause
Post by: lindero on 30 Jun 2009 09:25:06 AM
I agreed with blom0344. but further look at the roll-up processing setting. if this is set to database then all summarized data is calculated within the generated sql using these partition by clauses. set this property to local, the calculation is process on the report server.

cheers