On 2013-01-13 12:44:44 -0500, Tom Lane wrote: > Hannu Krosing <ha...@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.
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. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
