view of view

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?

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Kind Regards,
Keith