Horton

Re: ALTER TABLE ADD COLUMN fast default

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Thomas Munro <thomas.munro@enterprisedb.com>, David Rowley <david.rowley@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-02-20T06:42:58Z
Lists: pgsql-hackers 
Hi,

On 2018-02-17 00:23:40 +0100, Tomas Vondra wrote:
> Anyway, I consider the performance to be OK. But perhaps Andres could
> comment on this too, as he requested the benchmarks.

My performance concerns were less about CREATE TABLE related things than
about analytics workloads or such, where deforming is the primary
bottleneck.  I think it should be ok, but doing a before/after tpc-h of
scale 5-10 or so wouldn't be a bad thing to verify.

Greetings,

Andres Freund

Commits

  1. Clean up treatment of missing default and CHECK-constraint records.

  2. Fast ALTER TABLE ADD COLUMN with a non-NULL default

  3. Fix application of identity values in some cases