Horton

Re: PostgreSQL crashes with SIGSEGV

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Aleksandr Parfenov <a.parfenov@postgrespro.ru>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-03-28T17:30:49Z
Lists: pgsql-bugs, pgsql-hackers 
Peter Geoghegan <pg@bowt.ie> writes:
> On Mon, Mar 26, 2018 at 5:14 AM, Kyotaro HORIGUCHI
> <horiguchi.kyotaro@lab.ntt.co.jp> wrote:
>> If no one objects, I'll mark this as Ready for Commit in a couple
>> of days.

> Thank you for the review, Horiguchi-san. It's hard to decide how
> important each goal is when coming up with a back-patchable fix like
> this. When the goals are somewhat in competition with each other, a
> second or a third opinion is particularly appreciated.

It looks good to me.  The only real objection would be if someone came
up with a test case proving that there's a significant performance
degradation from the extra copies.  But given that these are back
branches, it would take a pretty steep penalty for me to want to take
the risk of refactoring to avoid that.

I've pushed it with some cosmetic adjustments.

			regards, tom lane

Commits

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

  2. Allow the built-in ordered-set aggregates to share transition state.

  3. Avoid integer overflow while sifting-up a heap in tuplesort.c.

  4. Allow avoiding tuple copy within tuplesort_gettupleslot().

  5. Remove should_free arguments to tuplesort routines.

  6. Fix use-after-free around DISTINCT transition function calls.

  7. Reuse abbreviated keys in ordered [set] aggregates.