[GENERAL] WITH SELECT * FROM function() WHERE etc InterRob Tue, 29 Sep 2009 03:00:41 -0700 Dear list, Say, I wish to have a function returning a record, taking a row as parameter. However, from a performance perspective, I wish to be able to perform this query only on a subset by using a WHERE-clause. I can only think of the following approach: WITH ss AS ( SELECT * FROM my_table) SELECT * FROM my_function(ss) WHERE ss.field1 > 100 Question is: does the optimizer apply this WHERE-clause to the WITH-SELECT (resulting in "ss")? Rob Previous message View by thread View by date Next message Reply via email to Search the site The Mail Archive home pgsql-general - all messages pgsql-general - about the list Expand Previous message Next message The Mail Archive home Add your mailing list FAQ Support Privacy 671e36b0909290300x51895efdw6790f458676a6a42@mail.gmail.com

[InterRob]

Dear list,
Say, I wish to have a function returning a record, taking a row as
parameter. However, from a performance perspective, I wish to be able to
perform this query only on a subset by using a WHERE-clause.

I can only think of the following approach:

WITH ss AS ( SELECT * FROM my_table) SELECT * FROM my_function(ss) WHERE
ss.field1 > 100

Question is: does the optimizer apply this WHERE-clause to the WITH-SELECT
(resulting in "ss")?


Rob