view of view

[Keith Worthington <KeithW@xxxxxxxxxxxxxxxxx>]

Hi All,

I am working on an application that uses PostgreSQL.  One of the 
functions of the application is to generate reports.  In order to keep 
the code in the application simple we create a view of the required data 
in the database and then simply execute a SELECT * FROM 
view_of_the_data;  All of the manipulation and most of the time even the 
ordering is handled in the view.

My question is how much if any performance degradation is there in 
creating a view of a view?

IOW if I have a view that ties together a couple of tables and 
manipulates some data what will perform better; a view that filters, 
manipulates, and orders the data from the first view or a view that 
performs all the necessary calculations on the original tables?

--
Kind Regards,
Keith