Horton

Re: pgsql: Add parallel-aware hash joins.

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Thomas Munro <thomas.munro@enterprisedb.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2018-01-24T20:18:26Z
Lists: pgsql-hackers 
Andres Freund wrote:

> Besides larger groups, starting the next test(s) earlier, another way to
> gain pretty large improvements would be a test schedule feature that
> allowed to stat dependencies between tests. So instead of manually
> grouping the schedule, have 'numerology' state that it depends on int2,
> int4, int8, float4, float8, which means it can actually be started
> earlier than it currently can in many cases.

Yeah, I proposed this a decade ago but never had the wits to write the
code.

It would be very useful for running tests standalone, too -- much as I
dislike 'make installcheck' taking half a minute, I dislike much more
having to take 5 minutes each time to figure out that create_table
depends on box, polygon, create_function, yadda yadda.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Update obsolete sentence in README.parallel.

  2. Rewrite ConditionVariableBroadcast() to avoid live-lock.

  3. Tweak parallel hash join test case in hopes of improving stability.

  4. Rename pg_rewind's copy_file_range() to avoid conflict with new linux syscall.

  5. Fix some minor errors in new PHJ code.

  6. Fix EXPLAIN ANALYZE output for Parallel Hash.

  7. Fix rare assertion failure in parallel hash join.

  8. Cancel CV sleep during subtransaction abort.

  9. Add parallel-aware hash joins.

  10. Fix EXPLAIN ANALYZE of hash join when the leader doesn't participate.

  11. Add some regression tests that exercise hash join code.