Received: from golem.jpl.nasa.gov (root@hectic-2.jpl.nasa.gov [128.149.68.204]) by hub.org (8.8.8/8.7.5) with ESMTP id VAA01310 for ; Tue, 19 May 1998 21:03:38 -0400 (EDT) Received: from alumni.caltech.edu (localhost [127.0.0.1]) by golem.jpl.nasa.gov (8.8.5/8.8.5) with ESMTP id BAA14472; Wed, 20 May 1998 01:07:58 GMT Sender: tgl@mythos.jpl.nasa.gov Message-ID: <35622CED.9B435442@alumni.caltech.edu> Date: Wed, 20 May 1998 01:07:57 +0000 From: "Thomas G. Lockhart" Organization: Caltech/JPL X-Mailer: Mozilla 4.03 [en] (X11; I; Linux 2.0.30 i686) MIME-Version: 1.0 To: Bruce Momjian CC: Tom Lane , Postgres Hackers List Subject: Re: [DOCS] Re: FE/BE protocol revision patch References: <199805191813.OAA20499@candle.pha.pa.us> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit > > 1. Implement addition of atttypmod field to RowDescriptor messages. > > The client-side code is there but ifdef'd out. I have no idea > > what to change on the backend side. The field should be sent > > only if protocol >= 2.0, of course. Hmm. I was hoping to do something in the backend to allow data types like numeric(p,s) which take multiple qualifying arguments (in this case, precision and scale). One possibility was to shoehorn both fields into the existing atttypmod 16-bit field. Seems like atttypmod is now being used for things outside of the backend, but I'm not sure how to support these other uses with these other possible data types. A better general approach to the type qualifier problem might be to define a variable-length data type which specifies column characteristics, and then pass that around. For character strings, it would have one field, and for numeric() and decimal() it would have two. Comments? Ideas?? - Tom