Hello Tom Sorry, but I did not get you. I know that the filtering in the where clause and can be pushed up or down in the parsing tree depending on the optimizer. So in this certain case, the result could be computed first and filtered by the where clause later.
Regards ________________________________ From: Tom Lane <[email protected]> To: salah jubeh <[email protected]> Cc: [email protected]; pgsql <[email protected]> Sent: Fri, April 15, 2011 5:49:35 PM Subject: Re: [GENERAL] correlated query as a column and where clause salah jubeh <[email protected]> writes: > But, why I can not use the alias of the select statement ( as in the > original > post) in the where clause. The select list can only be computed after the where clause has filtered the rows, so such a thing would be circular. regards, tom lane -- Sent via pgsql-general mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
