Michael W. Blasgen – Communications of the ACM

Research and Advances Oct 1 1981

System R, an experimental database system, was constructed to demonstrate that the usability advantages of the relational data model can be realized in a system with the complete function and high performance required for everyday production use. This paper describes the three principal phases of the System R project and discusses some of the lessons learned from System R about the design of relational systems and database systems in general.

Computing Applications

Author Archives

Research and Advances Nov 1 1977

An encoding method for multifield sorting and indexing

Sequences of character strings with an order relation imposed between sequences are considered. An encoding scheme is described which produces a single, order-preserving string from a sequence of strings. The original sequence can be recovered from the encoded string, and one sequence of strings precedes another if and only if the encoding of the first precedes the encoding of the second. The strings may be variable length, without a maximum length restriction, and no symbols need be reserved for control purposes. Hence any symbol may occur in any string. The scheme is useful for multifield sorting, multifield indexing, and other applications where ordering on more than one field is important.

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