Re: Unpredicatable behavior of volatile functions used - Mailing list pgsql-general

From Aleksander Kmetec
Subject Re: Unpredicatable behavior of volatile functions used
Date
Msg-id 45ABA794.40708@intera.si
Whole thread Raw
In response to Re: Unpredicatable behavior of volatile functions used in cursors  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Unpredicatable behavior of volatile functions used  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Tom Lane wrote:
> This isn't gonna work very well if your query involves sorting, because
> the SELECT-list is evaluated before the sort step ...
>
>             regards, tom lane
>

Thanks, this seems to solve my problem.

Some quick testing shows that util.row_number() only gets re-evaluated at every call if the subquery contains an ORDER
BY clause. Now we can predict whether we need to compensate for that just by looking at the original query.

Regards,
Aleksander

pgsql-general by date:

Previous
From: Alban Hertroys
Date:
Subject: Re: Autovacuum Improvements
Next
From: Tom Lane
Date:
Subject: Re: Glacially slow nested SELECT