Re: HELP: How much diskspace in /tmp per user

Posted in 1994

Clem W. Akins — 27 Jul 1994 12:18:03 -0400 — source: Informix-list mailing list archive (1991-1998)

In <199407262309.QAA16659@netcom11.netcom.com> diskmsys@netcom.com (Disk Emulation Sys) writes: > In article <30gr4r$k9u@emory.mathcs.emory.edu> you wrote: > : In <1994Jul15.053552.20462@hasler.ascom.ch> > : nbladt@autelca.ascom.ch (Norbert Bladt) writes: [intro stuff deleted] > : > 1. Where does Informix put, of course, silently its temporary files [discussion of how to size tmp space deleted] > Can you put this file in main memory? What effect would this have on > performance? > Robert at DES. > > -- > Disk Emulation Systems, Inc. (DES) > SCSI Solid-State Disk Emulators > 3080 Oakmead Village Dr., Santa Clara, CA 95051 > Phone: 408-727-5497, Fax: 408-727-5496 > I'm posting this because, while I can pontificate, I don't *really* know. Maybe someone has a more informed opinion. The short answer is "of course". And "it would greatly speed performance." The long answer involves cost. The size of the temp file generated during sorts can be very large (megabytes, easily) and you may not have enough main memory to accomodate db needs. Then you are in virtual memory and back to disk I/O limitations. Since Informix chose to perform temp activities on disk (originally in dbspace, now in filesystem space) I must (?) assume that they have performed this cost/benefit analysis and chose the path which made the most sense for the most customers. You, however, may not be one of those for whom the 'disk' solution is best. I'm sure there is some way to cause your temp space to be in main memory, but there will be costs associated with it and a site-specific break even point. Only the db-gods know for sure on which side of the line you stand. Wouldn't it be nice if there were simple answers to complex issues? Nahhhh! __________________________________________________________________ | Clem Akins Standard Disclaimers Apply | | Reynolds Metals Co. "Climb High, Cave Deep!" | | Muscle Shoals, Alabama USA cwakins@jabba.rmc.com | |________________________________________________________________|