From: | Kevin Grittner <kgrittn(at)ymail(dot)com> |
---|---|
To: | Stephen Frost <sfrost(at)snowman(dot)net>, Andres Freund <andres(at)2ndquadrant(dot)com> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Hannu Krosing <hannu(at)2ndquadrant(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: record identical operator |
Date: | 2013-09-18 16:12:29 |
Message-ID: | 1379520749.20027.YahooMailNeo@web162904.mail.bf1.yahoo.com |
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Lists: | pgsql-hackers |
Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> making an SQL operator for 'are these really the same bytes' to
> deal with what is essentially implementation detail is _very_
> grotty.
We already have some such operators, although Andres argues that
comparing to that isn't fair because we at least know it is a
string of characters; we're just ignoring character boundaries and
collations. Some of the operators use for the existing byte
comparison opclasses are:
~<~ ~<=~ ~>=~ ~>~
Go ahead and try them out with existing text values. Andres has
said that he has seen these used in production systems.
= and <> aren't listed above even though they do a byte-for-byte
comparison because, well, I guess because we have chosen to treat
two UTF8 strings which produce the same set of glyphs using
different bytes as unequal. :-/
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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