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Re: [HACKERS] Runtime Partition Pruning

David Rowley <david.rowley@2ndquadrant.com>

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From: David Rowley <david.rowley@2ndquadrant.com>
To: Beena Emerson <memissemerson@gmail.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Robert Haas <robertmhaas@gmail.com>, amul sul <sulamul@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Dilip Kumar <dilipbalaut@gmail.com>
Date: 2017-12-27T03:06:44Z
Lists: pgsql-hackers

Attachments

Hi,

Please find attached my 4th version this patch.

This is now based on v17 of Amit's faster partition pruning patch [1].
It also now includes Beena's tests which I've done some mostly
cosmetic changes to.

I've also fixed a few bugs, one in a case where I was not properly
handling zero matching partitions in nodeAppend.c.

Another change I've made is to now perform the partition pruning at
run-time using a new memory context that's reset each time we
redetermine the matching partitions. This was required since we're
calling a planner function which might not be too careful about
pfreeing memory it allocates. A test case I was running before making
this change ended out failing to palloc memory due to OOM.

I've not done anything about reducing the cost of the Append path when
runtime pruning is enabled. I'm still thinking over the best way to
handle that.

[1] https://www.postgresql.org/message-id/58c3e20a-a964-4fdb-4e7d-bd833e9bead1@lab.ntt.co.jp

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Initialize ExprStates once in run-time partition pruning

  2. Add bms_prev_member function

  3. Support partition pruning at execution time

  4. Document partprune.c a little better

  5. Fix crash in pg_replication_slot_advance

  6. Add parallel-aware hash joins.

  7. Fix typo.

  8. Allow --with-bonjour to work with non-macOS implementations of Bonjour.

  9. Mention need for --no-inc-recursive in rsync command