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Re: Re: logical changeset generation v3 - comparison to Postgres-R change set format

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Hannu Krosing <hannu@2ndQuadrant.com>
Cc: Noah Misch <noah@leadboat.com>, Markus Wanner <markus@bluegap.ch>, Andres Freund <andres@anarazel.de>, pgsql-hackers@postgresql.org
Date: 2013-01-13T17:44:44Z
Lists: pgsql-hackers 
Hannu Krosing <hannu@2ndQuadrant.com> writes:
> How do people feel about adding a real sameness operator ?

Just begs the question of "what's sameness?"

In many places we consider a datatype's default btree equality operator
to define sameness, but not all types provide a btree opclass (in
particular, anything that hasn't got a sensible one-dimensional sort
order will not).  And some do but it doesn't represent anything that
anyone would want to consider "sameness" --- IIRC, some of the geometric
types provide btree opclasses that sort by area.  Even for apparently
simple types like float8 there are interesting questions like whether
minus zero is the same as plus zero.

The messiness here is not just due to lack of a notation.

			regards, tom lane

Commits

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

  1. Background worker processes

  2. Rearrange storage of data in xl_running_xacts.

  3. Basic binary heap implementation.

  4. Embedded list interface

  5. Refactor xlog.c to create src/backend/postmaster/startup.c