Re: [SQL] Case Preservation disregarding case

-----Original Message-----
From: Stephan Szabo [mailto:sszabo@megazone.bigpanda.com]
Sent: Tuesday, October 31, 2006 10:23 AM
To: Chuck McDevitt
Cc: Tom Lane; beau hargis; pgsql-sql@postgresql.org;
pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] [SQL] Case Preservation disregarding case

On Tue, 31 Oct 2006, Chuck McDevitt wrote:

> We treated quoted identifiers as case-specific, as the spec requires.
>
> In the catalog, we stored TWO columns... The column name with case
> converted as appropriate (as PostgreSQL already does), used for
looking
> up the attribute,
> And a second column, which was the column name with the case exactly
as
> entered by the user.

Wouldn't using that second column's value tend to often violate 5.2SR10
(at least that's the reference item in SQL92)? AFAICT, that rule
basically
says that the regular identifier is equivalent to the case-folded one
for
purposes of information and definition schema and similar purposes which
seems like it would be intended to include things like column labeling
for
output. There's a little bit of flexibility there on both similar
purposes
and equivalence, though.


Equivalent, yes.  But I can interpret that clause it mean I can show
either the case folded or non-case-folded value in the information
schema, as they are equivalent.

Anyway, we have many things that are "enhancements" beyond the spec, and
this could also be considered an enhancement.