| Roy,
I am not an expert on Oracle and its particular (peculiar?) variant of
SQL, so my remarks may not be as helpful as others' might be. However,
I'll give you what I have available.
Note 11.11 in the DSRI conference (COOOKIE::DSRI) analyzes DSRI against
Codd's 12 rules. At the end of that note, there is an analysis of how, in
DSRI, to simulate those operations that are not specifically provided
(e.g., outer join). That may be of a *little* use to you.
I do not believe that VAX SQL currently implements the MINUS (the next
SQL standard will call it "DIFFERENCE") operator.
I believe that VAX SQL currently implements UNION.
In standard SQL, a join of any sort, including a cross product (CROSS), is
indicated simply by listing multiple tables in the FROM clause--the
keyword CROSS is not required and is at most a noise word (unless Oracle
has some clever new definition for the word or syntax for the feature).
OUTER JOIN is not yet, I believe, implemented in VAX SQL. However, it can
be simulated (DSRI 11.11) using UNIONs.
I do not believe that VAX SQL currently implements INTERSECT.
I can't imagine why Oracle would have a specific keyword for NON-EQUIJOIN,
but you can rest assured that VAX SQL can easily accomplish them by simply
using an operator other than "=" in the WHERE clause predicates.
Perhaps a VAX SQL maven can fill in the holes that I left.
Good luck,
Jim
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