Re: EXTERNAL storage and substring on long strings - Mailing list pgsql-performance

From Scott Cain
Subject Re: EXTERNAL storage and substring on long strings
Date
Msg-id 1060290951.6795.38.camel@localhost.localdomain
Whole thread Raw
In response to Re: EXTERNAL storage and substring on long strings  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
> snipped much discussion about EXTERNAL storage and substring speed

Joe and Tom,

Thanks for all of your help; I went back to my (nearly) production
database, and executed the `update feature set residues = residues
||'';` and then redid my benchmark.  Here's a summary of the results:

substr in perl                      0.83sec/op
substring on default text column    0.24sec/op
substring on EXTERNAL column        0.0069sec/op

There's that 2 orders of magnitude improvement I was looking for!

Thanks again,
Scott

--
------------------------------------------------------------------------
Scott Cain, Ph. D.                                         cain@cshl.org
GMOD Coordinator (http://www.gmod.org/)                     216-392-3087
Cold Spring Harbor Laboratory


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