Message-ID: <3C4E0EB1.1E3687FD@mascari.com>
Date: Tue, 22 Jan 2002 20:15:29 -0500
From: Mike Mascari <mascarm@mascari.com>
MIME-Version: 1.0
To: pgsql-hackers@postgresql.org
Subject: Re: RFD: schemas and different kinds of Postgres objects
References: <Pine.LNX.4.30.0201221824360.686-100000@peter.localdomain>
	<29436.1011744140@sss.pgh.pa.us>
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Tom Lane wrote:
> 
> I'm particularly troubled by the idea of trying to apply this "any"
> lookup concept to resolution of overloaded operators and functions.
> Suppose I have a reference func(type1,type2) that I'm trying to resolve,
> and I have an inexact match (one requiring coercion) in my own schema.
> Do I look to the "any" schema to see if there are better matches?
> If so, what happens if the "any" schema contains multiple possibilities
> with identical signatures (presumably created by different users)?  ISTM
> this will positively guarantee a resolution failure, since there's no
> way for the resolver to prefer one over another.  Thus, by creating
> a "func(foo,bar)" function --- quite legally --- JRandomLuser might
> break other people's formerly working queries that use other functions
> named func.  Although it's possible for this to happen now, it'll be
> a lot more surprising if JRandomLuser thinks that his functions live
> in his own private schema namespace.
>

So, in a nutshell, the price we pay for function overloading is the
inability to have schema-specific functions. Right? Possibly why Oracle
doesn't allow function overloading? As a user, I'd much rather have
schema-specific functions than only global. I'm not downplaying the
value of function overloading, but if I had the choice (which I guess I
can't/won't), I'd choose schema-specific functions over function
overloading...

Mike Mascari
mascarm@mascari.com