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Re: [HACKERS] Re: [SQL] DISTINCT ON: speak now or forever hold your peace

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Chris Bitmead <chris(at)bitmead(dot)com>
Cc: pgsql-hackers(at)postgreSQL(dot)org, pgsql-sql <pgsql-sql(at)postgreSQL(dot)org>
Subject: Re: [HACKERS] Re: [SQL] DISTINCT ON: speak now or forever hold your peace
Date: 2000-01-26 23:05:08
Message-ID: 19434.948927908@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-sql
Chris Bitmead <chris(at)bitmead(dot)com> writes:
> As long as we're fixing the syntax, I'm wondering if it wouldn't be more
> logical to have DISTINCT ON somewhere later in the syntax.

Well, SELECT DISTINCT is that way because SQL92 says so.  Putting the
DISTINCT ON variant somewhere else might be logically purer, but I think
it'd be confusing.

Also, isn't the reason we have DISTINCT ON at all that it's there to
be compatible with MySQL or someone?  I figured adding parens would be
about the least-surprising variant syntax for a person used to those
other products.

			regards, tom lane

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