Re: Enum proposal / design - Mailing list pgsql-hackers

From Jim C. Nasby
Subject Re: Enum proposal / design
Date
Msg-id 20060816225237.GU21363@pervasive.com
Whole thread Raw
In response to Re: Enum proposal / design  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Wed, Aug 16, 2006 at 04:13:43PM -0400, Tom Lane wrote:
> Tom Dunstan <pgsql@tomd.cc> writes:
> > I thought the runtime one was kinda cute, actually, but you would have 
> > to have duplicate functions for the differently sized types, eg. 
> > enum1_out, enum2_out etc since otherwise you wouldn't know what sized 
> > parameter you were just handed.
> 
> I'm not sure that that matters really.  What you are actually going to
> get handed is a Datum that IIRC is right-justified and zero-padded, so
> very probably one function would work for all stored widths.  The bigger
> issue I think is the surprise factor if a column gets wider over a dump
> and reload.

Actually, if we're going to support variable-width enums, I think it
makes the most sense to just expose that to the user, since they'll be
able to have a chance of figuring out which size would make the most
sense for a given table (unless you want to add logic to look at the
table's layout...)

If we wanted to provide an idiot-proof version that was "unsized", we
could just make that an alias for a 4 or 8 byte enum.
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461


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