RE: VOQL sessions in Beijing and DAL-VOQL joint sessions

From: Alex Szalay <szalay-at-jhu.edu>
Date: Fri, 4 May 2007 16:38:18 -0400


http://sqlbible.tar.hu/sqlbible0099.html

on ORACLE -- indeed not strictly verbatim compliant, but by and large has the same functionality. The above links show the translation

--Alex

-----Original Message-----
From: owner-voql-teg-at-eso.org [mailto:owner-voql-teg-at-eso.org] On Behalf Of Doug Tody
Sent: Friday, May 04, 2007 1:52 PM
To: Francois Ochsenbein
Cc: voql-teg-at-ivoa.net
Subject: Re: VOQL sessions in Beijing and DAL-VOQL joint sessions

On Fri, 4 May 2007, Francois Ochsenbein wrote:

> I could try to talk about the metadata requirements -- but the
> information_schema being something existing almost only in SQL server,
> I don't feel it would be wise to insist on this solution.
>
> Cheers, francois

Probably the implementation of information_schema is pretty mixed, although I got the impression that MySQL and PostgreSQL have a pretty good implementation as well, and possibly DB2 and INFORMIX (but not Oracle evidently). And of course SQL Server.

I suggest we consider the issue of an information_schema like approach, and the issue of whether to use the information_schema specification directly, as two separate issues. The key question is what metadata is required to compose non-trivial queries, as opposed to discovery/planning via the registry, where only very limited information is required, and whether these are the same or distinct. I just would hate to see TAP crippled by an approach which can't easily grow to support more sophisticated applications, and efficient execution of complex queries against large tables.

Received on 2007-05-04Z22:43:28