Horton

Re: Declarative partitioning - another take

Amit Langote <langote_amit_f8@lab.ntt.co.jp>

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From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Amit Langote <amitlangote09@gmail.com>, Dmitry Ivanov <d.ivanov@postgrespro.ru>, Michael Paquier <michael.paquier@gmail.com>, Andres Freund <andres@anarazel.de>, Erik Rijkers <er@xs4all.nl>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Pg Hackers <pgsql-hackers@postgresql.org>, pgsql-hackers-owner@postgresql.org
Date: 2017-02-03T02:31:26Z
Lists: pgsql-hackers 
On 2017/01/31 6:42, Peter Eisentraut wrote:
> On 1/25/17 12:54 AM, Ashutosh Bapat wrote:
>> The documentation available at
>> https://www.postgresql.org/docs/devel/static/sql-createtable.html,
>> does not make it clear that the lower bound of a range partition is
>> always inclusive and the higher one is exclusive. I think a note in
>> section " PARTITION OF parent_table FOR VALUES partition_bound_spec"
>> would be helpful.
> 
> Hmm.  I see the practical use of that, but I think this is going to be a
> source of endless confusion.  Can we make that a bit clearer in the
> syntax, for example by using additional keywords (INCLUSIVE/EXCLUSIVE)?

The decision not to make that configurable with INCLUSIVE/EXCLUSIVE syntax
was deliberate.  To summarize, we can start with a default configuration
catering to most practical cases (that is, inclusive lower and exclusive
upper bounds) and documenting so (not done yet, which I will post a doc
patch today for).  If it turns out that there is some demand for making
that configurable, we can later add the code to handle that internally
plus the syntax.  But *starting* with that syntax means we have to
potentially needlessly carry the code to handle seldom used cases that
could not be made as efficient as it is now with all lower bounds being
inclusive and upper bounds exclusive.

Thanks,
Amit

[1]
https://www.postgresql.org/message-id/CA%2BTgmoZou4ApEvC_nfhOxsi5G4SoD_evwNaiYn60ZcJ4XB_-QQ%40mail.gmail.com

Commits

  1. Fix typo.

  2. Document trigger-firing behavior for inheritance/partitioning.

  3. Fire per-statement triggers on partitioned tables.

  4. Set ecxt_scantuple correctly for tuple routing.

  5. Fix interaction of partitioned tables with BulkInsertState.

  6. Avoid core dump for empty prepared statement in an aborted transaction.

  7. Fix some problems in check_new_partition_bound().

  8. Remove unnecessary arguments from partitioning functions.

  9. Fix reporting of constraint violations for table partitioning.

  10. Fix tuple routing in cases where tuple descriptors don't match.

  11. Invalid parent's relcache after CREATE TABLE .. PARTITION OF.

  12. Doc: improve documentation about inheritance.