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efJicient storage hierorchies generally involves the repeated running of " typical " program address traces through a simulated storage system while various hierarchy design parameters are djusted. This paper describes a new and eficient method of determining, in one pass of an address trace, performance measures for a large class of demand-paged,(More)
Deterministic testing of SQL database systems is human intensive and cannot adequately cover the SQL input domain. A system (RAGS), was built to stochastically generate valid SQL statements 1 million times faster than a human and execute them. Good test coverage for commercial SQL database systems is very hard. The input domain, all SQL statements, from any(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)
The working-set concept is extended for programs that reference segments of different sizes. The generalized working-set policy (GWS) keeps as its resident set those segments whose retention costs do not exceed their retrieval costs. The GWS is a model for the entire class of demand-fetching memory policies that satisfy a resident-set inclusion property. A(More)
This paper describes the architecture of a proposed document composition system named JANUS, which is intended to provide support for authors of complex documents containing mixtures of text, line art, and tone art. The JANUS system is highly interactive, providing authors with immediate feedback and direct electronic control over page layouts, using a(More)