Abstract: In a distributed database system, at least one of the databases operates as a transaction manager and provides transparent commit coordination between an application program and other connected databases. The transaction manager incorporates a commit alteration procedure which enables selection of either a single phase commit protocol or a two phase commit protocol with respect to each database, during operation of the distributed system. The transaction manager establishes a commit protocol for each connected database; responds to a command from an application program by overriding a commit protocol previously established for a selected database and establishes another commit protocol for the selected database; performs a transaction and utilizes the another commit protocol in connection with the transaction; and upon completion of the transaction as evidenced by a successful commit action, enables establishment of another commit protocol.

Abstract: A system for managing database connections between concurrent user applications and a plurality of databases in a database processing system. This method minimizes the number of connections made to a database by allowing such connections to be shared by multiple applications. The concept of a shared versus exclusive connection is introduced and, depending on the user application, a connection manager automatically routes a database access request through either an existing shared connection or an exclusive connection. A single database access object is introduced that includes two types of methods for connecting to a specified database in two different simultaneous paths. First, a shared connection through a catalog server process is made to process schema query requests for definition retrieval. Secondly, another connection is made to retrieve and manipulate data from the database responsive to SQL execution requests.