Re: Use of the term "hierarchy"

From: Kenneth Downs <knode.wants.this_at_see.sigblock>
Date: Mon, 29 Aug 2005 12:56:36 -0400
Message-Id: <h9rbu2-096.ln1@pluto.downsfam.net>

Marshall Spight wrote:

> Kenneth Downs wrote:

>>
>> It seems the whole point of an invented table-column-oriented query is to
>> search in a wider scope, no?  If you don't want that then narrow the
>> scope:
>>
>> Select *.employee
>>   FROM (table1, table2, table)
>>   WHERE project_start < '2005-11-15'
>>
>> When you have completely disambiguated your query you are back to
>> conventional SQL.

>
> Interesting!
>
> I'm still a bit skittish about the idea of "seach" within
> a schema, but this example puts a different light on it.
>
>

Methinks it is OK if there are determistic rules about what will be returned, and if the server rejects a query it cannot disambiguate. So if three tables have "project_start" in them and also "employee" (assume same name=same thing) then an examination of foreign keys ought to determine when to UNION or JOIN. Perhaps this version:

Select Meta.Table_name,*.employee,*.project_start   WHERE project_start < '2005-11-15;

would return also where the data came from. An EXAMINE function would show the complete query tree.

-- 
Kenneth Downs
Secure Data Software, Inc.
(Ken)nneth@(Sec)ure(Dat)a(.com)

Received on Mon Aug 29 2005 - 11:56:36 CDT