Horton

Re: Problem with default partition pruning

Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>

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From: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
To: hosoya.yuzuko@lab.ntt.co.jp
Cc: Langote_Amit_f8@lab.ntt.co.jp, thibaut.madelaine@dalibo.com, imai.yoshikazu@jp.fujitsu.com, pgsql-hackers@lists.postgresql.org
Date: 2019-04-09T01:33:17Z
Lists: pgsql-hackers 
Sigh..

At Tue, 09 Apr 2019 10:28:48 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> wrote in <20190409.102848.252476604.horiguchi.kyotaro@lab.ntt.co.jp>
> As the second thought. Partition constraint is not constraint
> expression so that's fair to apply partqual ignoring
> constraint_exclusion. The variable is set false to skip useless
> expression evaluation on all partitions, but partqual should be
> evaluated just once.  Sorry for my confusion.
> 
> So still it is wrong that the new code is added in
> gen_partprune_steps_internal.

So still it is wrong that the new code is added at the beginning
of the loop on clauses in gen_partprune_steps_internal.

>                               If partqual results true and the
> clause is long, the partqual is evaluated uselessly at every
> recursion.
> 
> Maybe we should do that when we find that the current clause
> doesn't match part attributes. Specifically just after the for
> loop "for (i = 0 ; i < part_scheme->partnattrs; i++)".

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. Don't constraint-exclude partitioned tables as much

  2. Apply constraint exclusion more generally in partitioning

  3. Improve pruning of a default partition

  4. Doc: Fix event trigger firing table

  5. Remove obsolete nbtree insertion comment.