Horton

Re: WIP: [[Parallel] Shared] Hash

Haribabu Kommi <kommi.haribabu@gmail.com>

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From: Haribabu Kommi <kommi.haribabu@gmail.com>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2016-12-02T12:38:31Z
Lists: pgsql-hackers 
On Thu, Nov 3, 2016 at 4:19 PM, Thomas Munro <thomas.munro@enterprisedb.com>
wrote:

> Obviously I'm actively working on developing and stabilising all this.
> Some of the things I'm working on are: work_mem accounting, batch
> increases, rescans and figuring out if the resource management for
> those BufFiles is going to work.  There are quite a lot of edge cases
> some of which I'm still figuring out, but I feel like this approach is
> workable.  At this stage I want to share what I'm doing to see if
> others have feedback, ideas, blood curdling screams of horror, etc.  I
> will have better patches and a set of test queries soon.  Thanks for
> reading.
>
>
This patch doesn't receive any review. Patch is not applying properly to
HEAD.
Moved to next CF with "waiting on author" status.

Regards,
Hari Babu
Fujitsu Australia

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