Re: Query Optimiser

Posted in 1993

Larry Siden — Thu, 21 Oct 1993 15:01:00 — source: Informix-list mailing list archive (1991-1998)

>I know that the Informix optimizer uses statistics for part of its >optimization. Does it also use statistics for re-ordering the evaluation >of ANDed joins in the WHERE clause? Someone said in a meeting that the Informix 5.x optimizer is very sensitive to "update statistics". Of course, this can take quite a while on a large database, and it locks tables as it goes along.