Horton

Re: WIP: [[Parallel] Shared] Hash

David Steele <david@pgmasters.net>

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From: David Steele <david@pgmasters.net>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Rafia Sabih <rafia.sabih@enterprisedb.com>, Peter Geoghegan <pg@bowt.ie>, Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2017-03-28T15:51:56Z
Lists: pgsql-hackers 
Hi Thomas,

On 3/28/17 1:41 AM, Rafia Sabih wrote:
> On Mon, Mar 27, 2017 at 12:20 PM, Thomas Munro
>>
>> I thought this last point about Windows might be fatal to my design,
>> but it seems that Windows since at least version 2000 has support for
>> Unixoid unlinkability via the special flag FILE_SHARE_DELETE.

<...>

>
> Please find the attached file for the explain analyse output of these
> queries on head as well as patch.
> Would be working on analysing the performance of this patch on 300 scale factor.

I have marked this submission "Waiting for Author".  A new patch is 
needed to address Andres' comments and you should have a look at Rafia's 
results.

Thanks,
-- 
-David
david@pgmasters.net

Commits

  1. Add shared tuplestores.

  2. Remove BufFile's isTemp flag.

  3. Provide DSM segment to ExecXXXInitializeWorker functions.

  4. Optimize joins when the inner relation can be proven unique.

  5. Fix failure to use clamp_row_est() for parallel joins.

  6. Document lack of validation when attaching foreign partitions.

  7. Fix inclusions of c.h from .h files.

  8. Fix inclusions of postgres_fe.h from .h files.

  9. Bring plpgsql into line with header inclusion policy.

  10. Document intentional violations of header inclusion policy.

  11. Shut down Gather's children before shutting down Gather itself.

  12. btree: Support parallel index scans.

  13. Add explicit ORDER BY to a few tests that exercise hash-join code.

  14. Revise hash join code so that we can increase the number of batches

  15. Rewrite hash join to use simple linked lists instead of a