Home > Software > Data-Warehouse > DataStage
Interview Questions   Tutorials   Discussions   Programs   Discussion   

DataStage - What is usage of data stage with materialized views?

asked mar September 20, 2014 06:32 AM  

What is usage of data stage with materialized views?


1 Answers

answered By vishnoiprem   0  
A materialized view is like a query with a result that is materialized and stored in a table. When a user query is found compatible with the query associated with a materialized view, the user query can be rewritten in terms of the materialized view.
This technique improves the execution of the user query, because most of the query result has been pre-computed. The query transformer looks for any materialized views that are compatible with the user query and selects one or more materialized views to rewrite the user query.
The use of materialized views to rewrite a query is cost-based. That is, the query is not rewritten if the plan generated without the materialized views has a lower cost than the plan generated with the materialized views
   add comment

Your answer

Join with account you already have



Ready to start your tutorial with us? That's great! Send us an email and we will get back to you as soon as possible!