Horton

Re: Tid scan improvements

Edmund Horner <ejrh00@gmail.com>

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From: Edmund Horner <ejrh00@gmail.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: David Rowley <david.rowley@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, Thomas Munro <thomas.munro@gmail.com>, David Steele <david@pgmasters.net>, Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2019-09-05T01:06:56Z
Lists: pgsql-hackers 
On Wed, 4 Sep 2019 at 10:34, Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
>
> On 2019-Aug-01, Edmund Horner wrote:
>
> > Hi everyone,
> >
> > Sadly it is the end of the CF and I have not had much time to work on
> > this.  I'll probably get some time in the next month to look at the
> > heapam changes.
> >
> > Should we move to CF?  We have been in the CF cycle for almost a year now...
>
> Hello, do we have an update on this patch?  Last version that was posted
> was v9 from David on July 17th; you said you had made some changes on
> July 22nd but didn't attach any patch.  v9 doesn't apply anymore.

Hi pgsql-hackers,

I have had a lot of difficulty making the changes to heapam.c and I
think it's becoming obvious I won't get them done by myself.

The last *working* patch pushed the work into heapam.c, but it was
just a naive loop over the whole table.  I haven't found how to
rewrite heapgettup_pagemode in the way Andres suggests.

So, I think we need to either get some help from someone familiar with
heapam.c, or maybe shelve the patch.  It has been work in progress for
over a year now.

Edmund

Commits

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

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