Re: PoC/WIP: Extended statistics on expressions

pg.ddx.io  pgsql-hackers@postgresql.org mailing list archive  
help / color / mirror / Atom feed

From: Noah Misch <noah@leadboat.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: PoC/WIP: Extended statistics on expressions
Date: Thu, 10 Jun 2021 21:55:46 -0700
Message-ID: <20210611045546.GA573364@rfd.leadboat.com> (raw)
In-Reply-To: <4c98203c-8364-bb76-b502-d7b323ba55ba@enterprisedb.com>
References: <CAEZATCW2WHfsrbDLzwMvD+kOsBemLhvKwoHGhzR7STtac74XTg@mail.gmail.com>
	<a7d17aec-234d-c7f2-bfdc-99c87767a507@enterprisedb.com>
	<1ed534fb-b42b-f008-35ee-4eb930b0088f@enterprisedb.com>
	<CAEZATCV-JgFzb6aCJxApXg302u4vw+ajj702RHaBVkS_4JPVRg@mail.gmail.com>
	<2cb8a7cd-664f-8681-6ce9-790a50e3c78f@enterprisedb.com>
	<CAEZATCXsfFcXW_A1XCd5QK6zT2M_V+P3aPSktjibHHPzoV+Y-A@mail.gmail.com>
	<096d26e1-f053-a039-047d-a050dbb80ac6@enterprisedb.com>
	<078de413-8e4e-343e-fac1-eb61fd389925@enterprisedb.com>
	<20210606053740.GB297923@rfd.leadboat.com>
	<4c98203c-8364-bb76-b502-d7b323ba55ba@enterprisedb.com>

On Sun, Jun 06, 2021 at 09:13:17PM +0200, Tomas Vondra wrote:
> 
> On 6/6/21 7:37 AM, Noah Misch wrote:
> > On Sat, Mar 27, 2021 at 01:17:14AM +0100, Tomas Vondra wrote:
> >> OK, pushed after a bit more polishing and testing.
> > 
> > This added a "transformed" field to CreateStatsStmt, but it didn't mention
> > that field in src/backend/nodes.  Should those functions handle the field?
> > 
> 
> Yup, that's a mistake - it should do whatever CREATE INDEX is doing. Not
> sure if it can result in error/failure or just inefficiency (due to
> transforming the expressions repeatedly), but it should do whatever
> CREATE INDEX is doing.
> 
> Thanks for noticing! Fixed by d57ecebd12.

Great.  For future reference, this didn't need a catversion bump.  readfuncs.c
changes need a catversion bump, since the catalogs might contain input for
each read function.  Other src/backend/nodes functions don't face that.  Also,
src/backend/nodes generally process fields in the order that they appear in
the struct.  The order you used in d57ecebd12 is nicer, being more like
IndexStmt, so I'm pushing an order change to the struct.

view thread (107+ messages)  latest in thread

Message-ID: <20210611045546.GA573364@rfd.leadboat.com>
Permalink:  ../20210611045546.GA573364@rfd.leadboat.com/
Also on:    postgresql.org/message-id/20210611045546.GA573364@rfd.leadboat.com

 ·

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-hackers@postgresql.org
  Cc: noah@leadboat.com, tomas.vondra@enterprisedb.com, dean.a.rasheed@gmail.com, pryzby@telsasoft.com
  Subject: Re: PoC/WIP: Extended statistics on expressions
  In-Reply-To: <20210611045546.GA573364@rfd.leadboat.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox