Horton

Re: Optimise default partition scanning while adding new partition

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Jeevan Ladhe <jeevan.ladhe@enterprisedb.com>, PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2017-09-15T15:59:18Z
Lists: pgsql-hackers 
On Fri, Sep 15, 2017 at 2:00 AM, Amit Langote
<Langote_Amit_f8@lab.ntt.co.jp> wrote:
> I wonder if we should call check_default_allows_bound() from
> ATExecAttachPartition(), too, instead of validating updated default
> partition constraint using ValidatePartitionConstraints()?  That is, call
> the latter only to validate the partition constraint of the table being
> attached and call check_default_allows_bound() to validate the updated
> default partition constraint.  That way, INFO/ERROR messages related to
> default partition constraint are consistent across the board.

I believe the intended advantage of the current system is that if you
specify multiple operations in a single ALTER TABLE command, you only
do one scan rather than having a second scan per operation.  If that's
currently working, we probably don't want to make it stop working.

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

Commits

  1. Synchronize error messages.

  2. On CREATE TABLE, consider skipping validation of subpartitions.

  3. On attach, consider skipping validation of subpartitions individually.

  4. Improve error message when skipping scan of default partition.

  5. Allow a partitioned table to have a default partition.