Re: Informix and PDQ
}>From ilist@rmy.emory.edu Tue Apr 1 13:47:31 1997 }>Received: from rmy.rmy.emory.edu by hobbes.dbintellect.com via ESMTP (940816.SGI.8.6.9/930416.SGI.AUTO) }> for <settler@dbintellect.com> id NAA01683; Tue, 1 Apr 1997 13:47:19 -0700 }>Received: (from ilist@localhost) by rmy.rmy.emory.edu (8.7.1/8.7.1) id MAA06208 for informix-list-out; Tue, 1 Apr 1997 12:40:01 -0500 (EST) }>From: whsmith1@compuserve.com }>Message-Id: <859913458.21225@dejanews.com> }>Subject: Re: Informix and PDQ }>Date: Tue, 01 Apr 1997 11:01:59 -0600 }>Reply-To: whsmith1@compuserve.com }>Organization: Deja News Usenet Posting Service }>Sender: informix-list-owner@rmy.emory.edu }>To: informix-list@rmy.emory.edu }>X-Informix-List-Id: <news.36027> }> }>In article <19970401060701.BAA04436@ladder01.news.aol.com>, }> satriguy@aol.com (SaTriGuy) wrote: }>> }>> Just a comment. }>> }>> I'd suggest that anyone that is thinking of starting to turn on PDQ }>> initially simply set PDQ to 1. This will turn on parallel scanning for }>> CLIPPED . . . . . }> }>Thanks for the reminder. Parallel scans will be phase 1. Until I feel }>more comfortable with PDQ, I'll leave it at that. Maybe later I can }>experiment with resetting the MAX_PDQPRIORITY and other associated }>variables to produce a DSS environment during certain times, but that }>will come later. }> }>BTW, just for the record, PDQPRIORITY needs to be set at the SQL level, }>not at the engine level. I've seen things get quite scary when }>PDQPRIORITY is set in the ONCONFIG file. }> }>Anyone else out there have tidbits? reminders? experiences? warnings? }> }>John Carlson }>Informix DBA }>WH Smith Inc. }>Any of my ideas are mine alone and not necessarily those of my company. }> }>-------------------==== Posted via Deja News ====----------------------- }> http://www.dejanews.com/ Search, Read, Post to Usenet }> It would be nice if third-party products, such as BusinessObjects, allowed you to pass through PDQPRIORITY, but they do not, nor does I-Connect. Therefore, you may be forced to set it globally in order to gain its benefits. Note that as of Informix 7.2x, the PDQPRIORITY parameter in onconfig is obsolete, so global setting is accomplished via informix.rc file. Also, if you are running Informix 7.2x on Silicon Graphics IRIX 6.2, and you are running NUMCPUVPs > 1, and PDQPRIORITY is > 1, you will get incorrect results if the SQL contains count(distinct columnname). ------------------------------------------------------------------- Jeff Craig | dbINTELLECT Technologies, Inc. Senior Consultant | Golden, CO | (303) 275-6954 ext. 8008 | email: settler@dbintellect.com | fax: (303) 275-2134 -------------------------------------------------------------------