Re: Use of the term "hierarchy"

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)
.

Relevant Pages

  • Re: Use of the term "hierarchy"
    ... Scope is a good thing. ... It seems the whole point of an invented table-column-oriented query is to ... Kenneth Downs ...
    (comp.databases.theory)
  • Re: Use of the term "hierarchy"
    ... Kenneth Downs wrote: ... > It seems the whole point of an invented table-column-oriented query is to ... > search in a wider scope, ... but this example puts a different light on it. ...
    (comp.databases.theory)