Re: POC: GROUP BY optimization - Mailing list pgsql-hackers

From Tom Lane
Subject Re: POC: GROUP BY optimization
Date
Msg-id 2426725.1703653643@sss.pgh.pa.us
Whole thread Raw
In response to Re: POC: GROUP BY optimization  (Andrei Lepikhov <a.lepikhov@postgrespro.ru>)
Responses Re: POC: GROUP BY optimization  (Andrei Lepikhov <a.lepikhov@postgrespro.ru>)
List pgsql-hackers
Andrei Lepikhov <a.lepikhov@postgrespro.ru> writes:
> To be clear. In [1], I mentioned we can perform micro-benchmarks and 
> structure costs of operators. At least for fixed-length operators, it is 
> relatively easy.

I repeat what I said: this is a fool's errand.  You will not get
trustworthy results even for the cases you measured, let alone
all the rest.  I'd go as far as to say I would not believe your
microbenchmarks, because they would only apply for one platform,
compiler, backend build, phase of the moon, etc.

            regards, tom lane



pgsql-hackers by date:

Previous
From: Rian McGuire
Date:
Subject: [PATCH] pg_dump: Do not dump statistics for excluded tables
Next
From: Masahiko Sawada
Date:
Subject: Re: Synchronizing slots from primary to standby