Horton

Re: [HACKERS] Parallel tuplesort (for parallel B-Tree index creation)

Tomas Vondra <tomas.vondra@2ndquadrant.com>

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Peter Geoghegan <pg@bowt.ie>, Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, Amit Kapila <amit.kapila16@gmail.com>, Thomas Munro <thomas.munro@enterprisedb.com>, Rushabh Lathia <rushabh.lathia@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Pg Hackers <pgsql-hackers@postgresql.org>, Corey Huinker <corey.huinker@gmail.com>
Date: 2018-02-06T21:04:10Z
Lists: pgsql-hackers 
On 02/06/2018 09:56 PM, Peter Geoghegan wrote:
> On Tue, Feb 6, 2018 at 12:53 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>>> Do you want somebody who does have a working valgrind installation
>>> (ie me) to take responsibility for pushing this patch?
>>
>> I committed it before seeing this.  It probably would've been better
>> if you had done it, but I assume Peter tested it, so let's see what
>> the BF thinks.
> 
> I did test it with a full "make installcheck" + valgrind-3.11.0. I'd
> be very surprised if this doesn't make the buildfarm go green.
> 

Did you do a test with "-O0"? In my experience that makes valgrind tests
much more reliable and repeatable. Some time ago we've seen cases that
were failing for me but not for others, and I suspect it was due to me
using "-O0".

(This is more a random comment than a suggestion that you patch won't
make the buildfarm green.)

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Support parallel btree index builds.

  2. Report an ERROR if a parallel worker fails to start properly.

  3. Transfer state pertaining to pending REINDEX operations to workers.

  4. Add a barrier primitive for synchronizing backends.

  5. Allow DML commands that create tables to use parallel query.

  6. Refactor GetOldestXmin() to use flags

  7. Fix regression in parallel planning against inheritance tables.

  8. Don't create "holes" in BufFiles, in the new logtape code.

  9. Simplify the code for logical tape read buffers.

  10. Fix excessive memory consumption in the new sort pre-reading code.

  11. Implement binary heap replace-top operation in a smarter way.

  12. Cosmetic code cleanup in commands/extension.c.

  13. Speed up planner's scanning for parallel-query hazards.

  14. Read from the same worker repeatedly until it returns no tuple.

  15. Improve tuplesort.c to support variable merge order. The original coding