Re: Functions returning sets - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Functions returning sets
Date
Msg-id 7636.990319449@sss.pgh.pa.us
Whole thread Raw
In response to Re: Functions returning sets  (Don Baccus <dhogaza@pacifier.com>)
Responses Re: Functions returning sets  (Don Baccus <dhogaza@pacifier.com>)
List pgsql-hackers
Don Baccus <dhogaza@pacifier.com> writes:
> What's so hard about writing "IN" rather than "=" ???

Even more to the point, if we did adopt such a (crazy IMHO)
interpretation of '=', what makes anyone think that it'd be
any more efficient than IN?

AFAICT, mlw is hoping that redefining '=' would magically avoid the
performance problems with IN, but my bet is it'd be just the same.

What we need to do is teach the system how to handle WHERE ... IN ...
as a form of join.  Changing semantics of operators isn't necessary
nor helpful.
        regards, tom lane


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