Chapter 12 Distributed Database Management Systems

Distributed Database Management Systems 418 Discussion Focus Discuss the possible data request scenarios in a distributed database environment. 1. Single request accessing a single remote database. (See Figure D12.1.) Figure D12.1 Single Request to Single Remote DBMS REQUEST The most primitive and least effective of the distributed database scenarios is based on a single SQL statement (a "request" or "unit of work") is directed to a single remote DBMS. (Such a request is known as a remote request.). We suggest that you remind the student of the distinction between a request and a transaction:  A request uses a single SQL statement to request data.  A transaction is a collection of two or more SQL statements