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

From Tom Lane
Subject Re: Unpredicatable behavior of volatile functions used
Date
Msg-id 16491.1168878462@sss.pgh.pa.us
Whole thread Raw
In response to Re: Unpredicatable behavior of volatile functions used  (Aleksander Kmetec <aleksander.kmetec@intera.si>)
Responses Re: Unpredicatable behavior of volatile functions used
List pgsql-general
Aleksander Kmetec <aleksander.kmetec@intera.si> writes:
> 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.

If you're going to use a cursor, I don't understand why you don't just
MOVE FORWARD ALL and look at the returned rowcount to determine how
many rows in the query.  This won't be any more expensive than fetching
the last row ...

            regards, tom lane

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