Horton

Re: [HACKERS] Runtime Partition Pruning

Beena Emerson <memissemerson@gmail.com>

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From: Beena Emerson <memissemerson@gmail.com>
To: David Rowley <david.rowley@2ndquadrant.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: 2017-12-19T08:54:26Z
Lists: pgsql-hackers

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Hello,

On Mon, Dec 18, 2017 at 4:03 PM, David Rowley
<david.rowley@2ndquadrant.com> wrote:
>
>> We could do something similar here using a similar code structure.  Maybe,
>> add a ExecSetupPartitionRuntimePruning() in execPartition.c (mimicking
>> ExecSetupPartitionTupleRouting), that accepts AppendState node.
>> Furthermore, it might be a good idea to have something similar to
>> ExecFindPartition(), say, ExecGetPartitions().  That is, we have new
>> functions for run-time pruning that are counterparts to corresponding
>> functions for tuple routing.
>
> Seems to me in this case we're better to build this structure during
> planning and save it with the plan so that it can be used over and
> over, rather than building it again and again each time the plan is
> executed. Likely a common use case for run-time pruning is when the
> plan is going to be used multiple times with different parameters, so
> we really don't want to repeat any work that we don't have to here.
>

I agree. It would be better to avoid building the structure during execution.
PFA the updated patch.

--

Beena Emerson

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

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