Horton

Re: A potential memory leak on Merge Join when Sort node is not below Materialize node

David Rowley <dgrowleyml@gmail.com>

View thread View on postgr.es
From: David Rowley <dgrowleyml@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Ronan Dunklau <ronan.dunklau@aiven.io>, Önder Kalacı <onderkalaci@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-09-28T23:34:51Z
Lists: pgsql-hackers 
On Thu, 29 Sept 2022 at 12:30, Michael Paquier <michael@paquier.xyz> wrote:
>
> On Thu, Sep 29, 2022 at 11:58:17AM +1300, David Rowley wrote:
> > I've just pushed the disable byref Datums patch I posted earlier. I
> > only made a small adjustment to make use of the TupleDescAttr() macro.
> > Önder, thank you for the report.
>
> Wouldn't it be better to have 3a58176 reflect the non-optimization
> path in the EXPLAIN output of a new regression test if none of the
> existing tests are able to show any difference?

There's nothing in EXPLAIN that shows that this optimization occurs.
Or, are you proposing that you think there should be something? and
for 15??

David

Commits

  1. Allow nodeSort to perform Datum sorts for byref types

  2. Restrict Datum sort optimization to byval types only

  3. Make nodeSort.c use Datum sorts for single column sorts

  4. Fix actual and potential double-frees around tuplesort usage.

  5. Allow avoiding tuple copy within tuplesort_gettupleslot().