pgsql: Fix accounting of memory needed for merge heap. - Mailing list pgsql-committers

From Heikki Linnakangas
Subject pgsql: Fix accounting of memory needed for merge heap.
Date
Msg-id E1cEtwb-0007xm-Nd@gemulon.postgresql.org
Whole thread Raw
Responses Re: pgsql: Fix accounting of memory needed for merge heap.  (Peter Geoghegan <pg@heroku.com>)
List pgsql-committers
Fix accounting of memory needed for merge heap.

We allegedly allocated all remaining memory for the read buffers of the
sort tapes, but we allocated the merge heap only after that. That means
that the allocation of the merge heap was guaranteed to go over the memory
limit. Fix by allocating the merge heap first. This makes little difference
in practice, because the merge heap is tiny, but let's tidy.

While we're at it, add a safeguard for the case that we are already over
the limit when allocating the read buffers. That shouldn't happen, but
better safe than sorry.

The memory accounting error was reported off-list by Peter Geoghegan.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/f7d54f4f7ddf72bf4db1783890b058e758b4b894

Modified Files
--------------
src/backend/utils/sort/tuplesort.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)


pgsql-committers by date:

Previous
From: Robert Haas
Date:
Subject: pgsql: Replace references to COLLATE "en_CA" with COLLATE "POSIX".
Next
From: Heikki Linnakangas
Date:
Subject: pgsql: Clean up password authentication code a bit.