Re: Performance question

Posted in 1997

Vic Goldberg — Fri, 14 Nov 1997 13:42:23 -0500 — source: Informix-list mailing list archive (1991-1998)

Willie L. Meeks wrote: > > I have a question related to PDQ. Can any one explain to me why when you > run a query with PDQ enabled it appears that your cpu vp's don't work as > hard. PDQ will only buy you much of anything if you have your data fragmented. Have you taken a look at the sqexplain output? That may give the first clue. The explain output will be different if you are running with PDQ (higher than 1, of course), than if not. In addition, back in 7.1 days (and I don't know if this has been fixed), I found a bug (at least on Solaris) that if the PDQ was less than 12, inefficient use of the CPUs was the case. Vic -- Vic Goldberg Manager, Database Administration Team Cornell Information Technologies (607) 254-7441 (voice) (607) 255-6982 (fax)