Horton

Re: WIP: [[Parallel] Shared] Hash

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Andres Freund <andres@anarazel.de>, Rafia Sabih <rafia.sabih@enterprisedb.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2017-03-27T02:56:59Z
Lists: pgsql-hackers 
On Sun, Mar 26, 2017 at 6:50 PM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> Like you, I also tend to suspect that people would be more likely to
> use RAID type technologies to stripe things like this for both
> bandwidth and space reasons these days.  Tablespaces seem to make more
> sense as a way of separating different classes of storage
> (fast/expensive, slow/cheap etc), not as an IO or space striping
> technique.

I agree.

-- 
Peter Geoghegan

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