On 2013-01-13 12:44:44 -0500, Tom Lane wrote:
> Hannu Krosing <hannu(at)2ndQuadrant(dot)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.
FWIW *I* (but others might) don't plan to support that case for now, it
just seems to be too messy for far too little benefit.
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
In response to
pgsql-hackers by date
|Next:||From: Andres Freund||Date: 2013-01-13 18:07:33|
|Subject: Re: [PATCH] unified frontend support for pg_malloc et al
and palloc/pfree mulation (was xlogreader-v4)|
|Previous:||From: Markus Wanner||Date: 2013-01-13 18:02:46|
|Subject: Re: Re: logical changeset generation v3 - comparison to
Postgres-R change set format|