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.
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............