Horton

Re: Tuple sort is broken. It crashes on simple test.

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Peter Geoghegan <pg@heroku.com>
Cc: Michael Paquier <michael.paquier@gmail.com>, Mithun Cy <mithun.cy@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>
Date: 2017-01-16T18:56:46Z
Lists: pgsql-hackers 
2017-01-16 19:43 GMT+01:00 Peter Geoghegan <pg@heroku.com>:

> On Mon, Jan 16, 2017 at 10:38 AM, Pavel Stehule <pavel.stehule@gmail.com>
> wrote:
> > Should not be enhanced regress tests too?
>
> We already have coverage of multi-pass external tuplesorts, as of a
> few months back. That didn't catch this bug only because it was a
> pass-by-value datum tuplesort. The relevant RELEASE_SLAB_SLOT() call
> does have line coverage already.
>
> I wouldn't object to adding a test case that would have exercised this
> bug, too. It took me a while to talk Tom into the test that was added
> several months back, which discouraged me from adding another test
> case here. (There were concerns about the overhead of an external sort
> test on slower buildfarm animals.)
>

ok



>
> --
> Peter Geoghegan
>

Commits

  1. Fix NULL pointer dereference in tuplesort.c.

  2. Change the way pre-reading in external sort's merge phase works.