Horton

Re: ALTER TABLE ADD COLUMN fast default

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrew Gierth <andrew@tao11.riddles.org.uk>
Cc: Andrew Dunstan <andrew@dunslane.net>, Andres Freund <andres@anarazel.de>, Thomas Munro <thomas.munro@enterprisedb.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2021-04-06T15:01:55Z
Lists: pgsql-hackers 
Andrew Gierth <andrew@tao11.riddles.org.uk> writes:
> This gitlab ticket refers to the same incident:
> https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/6047
> (which actually contains a new relevant fact that hadn't been mentioned
> in the IRC discussion, which is that the problem affected multiple
> tables, not just one.)

Hmm.  If you assume that the problem is either a corrupted index on
pg_attrdef, or some block(s) of pg_attrdef got zeroed out, then it
would be entirely unsurprising for multiple tables to be affected.

I've pushed the v2 patch to HEAD.  Not sure if we want to consider
back-patching.

			regards, tom lane

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