Re: [HACKERS] sort on huge table - Mailing list pgsql-hackers

From Don Baccus
Subject Re: [HACKERS] sort on huge table
Date
Msg-id 3.0.1.32.19991101183500.00ab5d80@mail.pacifier.com
Whole thread Raw
In response to Re: [HACKERS] sort on huge table  (Mike Mascari <mascarim@yahoo.com>)
Responses Re: [HACKERS] sort on huge table  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
At 06:24 PM 11/1/99 -0800, Mike Mascari wrote:

>I know this is a VERY long shot, but... what were the READ/WRITE ratios
>between the old version and the new version? Perhaps the computation
>of the checksum (sic) blocks under RAID5 caused the unexpected behavior. 
>With RAID 5 increasing read performance but decreasing writes, one might 
>expect a new algorithm which say, halves reads, but increases writes 
>slightly to not realize the same benefits as under a normal disk system or
>a RAID 1 (or, better yet, a RAID 0+1) array.

RAID 5, not the operating system, might be getting in the way...it
would be interesting to test this on a Linux 2.2 kernel without
the RAID 5 complication.



- Don Baccus, Portland OR <dhogaza@pacifier.com> Nature photos, on-line guides, Pacific Northwest Rare Bird Alert
Serviceand other goodies at http://donb.photo.net.
 


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