Robert A. Yost

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This article presents and discusses the computation and communication model used by R*, a prototype distributed database management system. An R* computation consists of a tree of processes connected by virtual circuit communication paths. The process management and communication protocols used by R* enable the system to provide reliable, distributed(More)
System R supports a high-level relational user language called SQL which may be used by ad hoc users at terminals or as an embedded data sublanguage in PL/I or COBOL. Host-language programs with embedded SQL statements are processed by the System R precompiler which replaces the SQL statements by calls to a machine-language access module. The precompilation(More)
0018-8670/99/$5.00 © 1999 IBM IBM SYSTEMS JOURNAL, VOL38, NOS 2&3, 1999 BLASGEN ETAL. System R is an experimental data base management system that was designed to be unusually easy to use. System R supports a high-level relational user language called SQL, which may be used by ad hoc users at terminals or by programmers as an imbedded data sublanguage in(More)
R* is an experimental prototype distributed database management system. The computation needed to perform a sequence of multisite user transactions in R* is structured as a <italic>tree</italic> of processes communicating over virtual circuit communication links. Distributed computation can be supported by providing a server process per site which performs(More)
Throughout the history of information storage in computers, one of the most readily observable trends has been the focus on data independence. C.J. Date [27] defined data independence as "immunity of applications to change in storage structure and access strategy." Modern database systems offer data independence by providing a high-level user interface(More)
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