Horton

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

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: 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: 2018-01-19T12:52:26Z
Lists: pgsql-hackers 
On Thu, Jan 18, 2018 at 2:05 PM, Peter Geoghegan <pg@bowt.ie> wrote:
> Review of your patch:
>
> * SerializedReindexState could use some comments. At least a one liner
> stating its basic purpose.

Added a comment.

> * The "System index reindexing support" comment block could do with a
> passing acknowledgement of the fact that this is serialized for
> parallel workers.

Done.

> * Maybe the "Serialize reindex state" comment within
> InitializeParallelDSM() should instead say something like "Serialize
> indexes-pending-reindex state".

That would require corresponding changes in a bunch of other places,
possibly including the function names.  I think it's better to keep
the function names shorter and the comments matching the function
names, so I did not make this change.

> Other than that, looks good to me. It's a simple patch with a clear purpose.

Committed.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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