HOW 'VIEW' WORKS

I have a question about exactly how VIEW works in ORACLE.

I am working a bunch of reports which use a VIEW which is a UNION of 2 hugh tables(150000 and 100000 rows respectively.) The report SQL statement will use this view to join with other tables to select the columns required.

I would like to know how the SQL statement will be processed internally? Will the VIEW be created first(i.e. full table scan, sort/merge ...etc) THEN join with other tables OR the create statement of the VIEW will be combined with the report SQL statement first then process in one go.

Thanks,

Alex Received on Sat Sep 21 1996 - 00:00:00 CEST