Horton

Re: Avoid FK validations for no-rewrite ALTER TABLE ALTER TYPE

Noah Misch <noah@leadboat.com>

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From: Noah Misch <noah@leadboat.com>
To: Alvaro Herrera <alvherre@commandprompt.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2012-01-26T03:39:56Z
Lists: pgsql-hackers

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Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Damage control for yesterday's CheckIndexCompatible changes.

Attachments

On Wed, Jan 25, 2012 at 11:17:27AM -0300, Alvaro Herrera wrote:
> 
> Excerpts from Noah Misch's message of dom ene 22 02:05:31 -0300 2012:
> 
> > Thanks.  I've attached a new version fixing this problem.
> 
> Looks good to me.  Can you please clarify this bit?
> 
> 			 * Since we elsewhere require that all collations share the same
> 			 * notion of equality, don't compare collation here.
> 
> Since I'm not familiar with this code, it's difficult for me to figure
> out where this "elsewhere" is, and what does "same notion of equality"
> mean.

Good questions.  See the comment in front of ri_GenerateQualCollation(), the
comment in process_ordered_aggregate_single() at nodeAgg.c:605, the larger
comment in add_sort_column(), and the two XXX comments in
relation_has_unique_index_for().  We should probably document that assumption
in xindex.sgml to keep type implementors apprised.

"Same notion of equality" just means that "a COLLATE x = b COLLATE y" has the
same value for every x, y.

In any event, the patch needed a rebase, so I've attached it rebased and with
that comment edited to reference ri_GenerateQualCollation(), that being the
most-relevant source for the assumption in question.

Thanks for reviewing,
nm