Reply to Re: Different query plans for view and view definition statement

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Posted by --CELKO-- on 03/13/06 01:08

A VIEW is handled two ways in SQL. The text of the VIEW is "pasted"
into the query that uses it and then the parser and optimizer handle it
as if the query had been written with a derived table. The parser can
do a lot stuff at this point, so the original view text is "spread out
all over the place".

The second way is materialize the VIEW as a temporary table. The good
news is that this materialized table can be shared by multiple users,
so the overall processing time goes down, even if each user's plan is
not optimal for their query. This is a feature of larger SQL products
like Ingres, DB2 or Oracle.

Trust in the optimizer, Luke.

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