ADQL simplified

From: Martin Hill <mchill-at-dial.pipex.com>
Date: Fri, 16 Jan 2004 17:23:22 +0000


I'm working on a simpler ADQL that is less verbose and so easier for humans and tools to process. However I wanted to check first, is there a particular reason   why values are so fully (and somewhat redundantly) specified? eg <Value><NumberLiteral><IntNum><Value>3</Value...etc? Was it just to specify the values fully?

As far as I can tell, specifying type (ie integer, string or real) offers no extra checking in practice, as we can't tell what types the columns are that are being compared with (and it would be hard to validate anyway). Also, it doesn't match the way that numbers are used in the Region schema. And we lose this information when we convert backwards and forwards to the SQL-like string format - or is this no longer considered important?

Similarly with the functions - we have eg <Function><AggregateFunction><SUM> rather than just <Function><SUM> (or indeed <SUM>)

Would anyone have any objections to removing these redundant nested tags? Or point out which wrong end of the stick I'm holding?

Cheers,

Martin

-- 
Software Engineer
AstroGrid @ ROE
Tel: +44 7901 55 24 66
www.astrogrid.org
Received on 2004-01-16Z18:24:01