Horton

Re: Extended statistics is not working on Vars hidden under a RelabelType

Tomas Vondra <tomas.vondra@2ndquadrant.com>

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Robert Haas <robertmhaas@gmail.com>, David Rowley <david.rowley@2ndquadrant.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>, Álvaro Herrera <alvaro.herrera@2ndquadrant.com>
Date: 2017-10-13T20:44:04Z
Lists: pgsql-hackers 
On 10/13/2017 10:04 PM, Robert Haas wrote:
> On Mon, Oct 9, 2017 at 11:03 PM, David Rowley
> <david.rowley@2ndquadrant.com> wrote:
>> -- Unpatched
>>  Planning time: 0.184 ms
>>  Execution time: 105.878 ms
>>
>> -- Patched
>>  Planning time: 2.175 ms
>>  Execution time: 106.326 ms
> 
> This might not be the best example to show the advantages of the
> patch, honestly.
> 

Not sure what exactly is your point? If you're suggesting this example
is bad because the planning time increased from 0.184 to 2.175 ms, then
perhaps consider the plans were likely generated on a assert-enabled
build and on a laptop (both of which adds quite a bit of noise to
occasional timings). The patch has no impact on planning time (at least
I've been unable to measure any).

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Infer functional dependency past RelabelType