Sub operators ?
Date: 21 Sep 2006 03:15:40 -0700
Message-ID: <1158833740.749321.112280_at_e3g2000cwe.googlegroups.com>
A problem on which I hope having some feedback (Hostile and offtopic people can go fuck themselves from now on)...All others are welcome...
First, suppose relation R-1 extracting values from domain DoR1 and restricting values to produce domain DoR2. Suppose only one operator applies to DoR1 and DoR2 relvalues: JOIN.
Second, consider relations R-2 and R-3 being subject to 1:N cardinality with R-1. Based on above definition only JOIN are *possible* operators with any other relation R-N.
The problem arises in the fact that all R-2 and R-3 FK's define all a separate predicate with each new JOIN. Such predicate maybe expressed by *passive form verbs* such as
(R-(2)) takenby (R-1)) --> R-(2)) JOIN (R-1) --> produces X-Tuple
set
(R-(3)) drivenby (R-1)) --> R-(3)) JOIN (R-1) --> produces Y-Tuple
set
As JOIN is the only operator, what can be said of operators (takenby, drivenby)? How could these be better characterized in their relationship to the prime operator in this case JOIN?
Has anybody thought of such problem... Received on Thu Sep 21 2006 - 12:15:40 CEST