Re: XQuery question

> Given meta-data tables that describe relations between tables, and the names
> of two columns in any two tables, determine if a set of JOIN conditions can
> be constructed for a generated SELECT statement.

I see the potential use, but wouldn't that be a very limited graph since according to Date's 6th Ed "Intro to Db Sys" each tuple's attribute is based on a domain and domains are defined as having scalar values, or has this been corrected? If domains have scalar values, wouldn't the number of levels to determine whether two attributes are joinable always be the same?

> ... "describe relations between tables" ...

Since the relational data model (rdm) defines a "relation" as being a set of tuples which is generally conceptualized as a table, the above sentence in rdm-speak would translate to "tables between tables" which is probably not what you meant. What word did rdm formally assign to the word "relation" as used in the above sentence? Surely rdm has a formal word for that very basic and fundamental concept. Received on Mon May 19 2003 - 15:06:22 CEST