Showing posts with label analytics. Show all posts
Showing posts with label analytics. Show all posts

Tuesday, 31 March 2009

How to overcome IN clause limitation in Analytics?

In analytics, whever we use In caluse in filetr condition, the default
value is 8192.

If we expect thevalue be more than 8192 then we can increase it by
setting the parameter
MAX_EXPANDED_SUBQUERY_PREDICATES = 16384; in NQSConfig.ini file.

But this definetely impacts performance.

In obiee, you can use write back as work around for this issue.

Sunday, 22 March 2009

Write Back feature in OBIEE

Write back is a new feature introduced by oracle for improving performance.
In this article i will take you thro' one of the use of write back functionality.

Scenario:
Consider a scenario where in you want to use the output of another report as filter condition to main report.
In analytics, it's passed as IN clause. Now, when i talk about IN cluse, in TOAD you can pass only 1000 values in IN clause In analytics it's handled thro' Global setting defined in NQSConfig file. Default is 2^13.
If i pass that many value in IN clause, analytics services will go for a toss and most of the time it goes in timeout state.
to over come this, you can use Write back feature in OBIEE and store the outputs in temp tables. Analytics drops this table when the transaction is complete. the advantage of this feature is that you can pass even a million value in filter condition.
This feature well utilised in Marketing part of OBIEE.

To implement this feature, the schema should have write access to it's space.

Bog me more info............
-Nhanna