Re: Tid scan improvements

David Steele <david@pgmasters.net>

From: David Steele <david@pgmasters.net>
To: Edmund Horner <ejrh00@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, David Rowley <david.rowley@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2019-03-26T06:24:30Z
Lists: pgsql-hackers
On 3/26/19 8:11 AM, Edmund Horner wrote:
> On Tue, 26 Mar 2019 at 11:54, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>
>> Andres Freund <andres@anarazel.de> writes:
>>> I was kinda hoping to keep block numbers out of the "main" APIs, to
>>> avoid assuming everything is BLCKSZ based. I don't have a particular
>>> problem allowing an optional setscanlimits type callback that works with
>>> block numbers. The planner could check its presence and just not build
>>> tid range scans if not present.  Alternatively a bespoke scan API for
>>> tid range scans, like the later patches in the tableam series for
>>> bitmap, sample, analyze scans, might be an option.
>>
>> Given Andres' API concerns, and the short amount of time remaining in
>> this CF, I'm not sure how much of this patch set we can expect to land
>> in v12.  It seems like it might be a good idea to scale back our ambitions
>> and see whether there's a useful subset we can push in easily.
> 
> I agree.  It'll take some time to digest Andres' advice and write a
> better patch.
> 
> Should I set update CF app to a) set the target version to 13, and/or
> move it to next commitfest?

If you plan to continue working on it in this CF then you can just 
change the target to PG13.  If you plan to take a break and pick up the 
work later then go ahead and push it to the next CF.

Regards,
-- 
-David
david@pgmasters.net


Commits

  1. Add TID Range Scans to support efficient scanning ranges of TIDs

  2. Improve planner's selectivity estimates for inequalities on CTID.