Re: PseudoPartitioning and agregates - Mailing list pgsql-hackers

From Greg Stark
Subject Re: PseudoPartitioning and agregates
Date
Msg-id 87fywb8h7k.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: PseudoPartitioning and agregates  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane <tgl@sss.pgh.pa.us> writes:

> Greg Stark <gsstark@mit.edu> writes:
>
> > How hard would it be to have Postgres actually remove the gettimeofday
> > overhead from the EXPLAIN ANALYZE output? 
> 
> Personally, I dislike measurement tools that lie to you under the flag
> of producing more-easily-interpreted results.

This is pretty standard practice for profilers in other contexts.

> As an example of why this would be a bad idea, the total time would no
> longer be closely related to the actual elapsed time (as measured by
> psql's \timing for instance) so you would be entirely unable to tell
> whether there was some significant factor not being measured.

Well that would be easily remedied by printing the total overhead subtracted
from all the nodes after the plan.

-- 
greg



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