Horton

Re: Partitioning vs ON CONFLICT

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

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From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Peter Geoghegan <pg@bowt.ie>, "Shinoda, Noriyoshi" <noriyoshi.shinoda@hpe.com>, Simon Riggs <simon@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Thom Brown <thom@linux.com>
Date: 2017-08-01T04:26:01Z
Lists: pgsql-hackers 
On 2017/08/01 10:52, Robert Haas wrote:
> On Mon, Apr 3, 2017 at 6:28 AM, Amit Langote
> <Langote_Amit_f8@lab.ntt.co.jp> wrote:
>> Since nowhere has the user asked to ensure unique(b) across partitions by
>> defining the same on parent, this seems just fine.  But one question to
>> ask may be whether that will *always* be the case?  That is, will we take
>> ON CONFLICT DO NOTHING without the conflict target specification to mean
>> checking for conflicts on the individual leaf partition level, even in the
>> future when we may have global constraints?
> 
> No.  We'll take it to mean that there is no conflict with any unique
> constraint we're able to declare.  Currently, that means a
> partition-local unique constraint because that's all there is.  It
> will include any new things added in the future.

So is the latest patch posted upthread to process ON CONFLICT DO NOTHING
using locally-defined unique indexes on leaf partitions something to consider?

Maybe, not until we have cascading index definition working [1]?

Thanks,
Amit

[1]
https://www.postgresql.org/message-id/c8fe4f6b-ff46-aae0-89e3-e936a35f0cfd%40postgrespro.ru

Commits

  1. Revert "Allow ON CONFLICT .. DO NOTHING on a partitioned table."

  2. Allow ON CONFLICT .. DO NOTHING on a partitioned table.