Re: cpu_tuple_cost - Mailing list pgsql-performance

From Tom Lane
Subject Re: cpu_tuple_cost
Date
Msg-id 8149.1111005738@sss.pgh.pa.us
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In response to Re: cpu_tuple_cost  (Josh Berkus <josh@agliodbs.com>)
Responses Re: cpu_tuple_cost
List pgsql-performance
Josh Berkus <josh@agliodbs.com> writes:
>> So what's going on with the empirically derived value of 4?

> It's not empirically derived;

Yes it is.  I ran experiments back in the late 90s to derive it.
Check the archives.

Disks have gotten noticeably bigger since then, but I don't think
the ratio of seek time to rotation rate has changed much.

            regards, tom lane

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