Re: ALTER TABLE ADD COLUMN fast default

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Andres Freund <andres(at)anarazel(dot)de>
Cc: Petr Jelinek <petr(dot)jelinek(at)2ndquadrant(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Andrew Dunstan <andrew(dot)dunstan(at)2ndquadrant(dot)com>, Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com>, David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: ALTER TABLE ADD COLUMN fast default
Date: 2018-02-20 18:07:30
Message-ID: 10938.1519150050@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

... btw, I've not read this patch in any detail, but the recent thread
about toast tables for system catalogs prompts me to wonder what happens
if a "fast default" value is large enough to require out-of-line toasting.

I can easily think of problems that will ensue if we try to support that
case, because right now the toast mechanisms assume that OOL toasted
values can only be referenced from the associated table.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Patrick Krecker 2018-02-20 18:09:16 Re: Option to ensure monotonic timestamps
Previous Message Andres Freund 2018-02-20 17:51:51 Re: Option to ensure monotonic timestamps