11. IntroductionCypress was motivated by the need for database management facilities in Cedar. Its goals are (1)convenience, making it easy to build new database applications in Cedar, and (2) reasonableperformance for a wide class of applications. If you are unsure whether an application you have inmind is appropriate, talk to someone who has built one. You should also consult others to see whatauxiliary documentation and folklore is available.The conceptual data structure provided by a database system, analogous to the Mesa type system, iscalled a data model. The data model specifies how data may be structured and accessed; thus thedata model is what you need to know in order to use the system. The Cypress data modeldescribed herein includes features that are accepted in some form in a number of models in theliterature, particularly those that seemed most useful for database applications we envision in CSL.The data model is described conceptually in Section 2. In Section 3 we describe the Cedar interfaceto Cypress: DB.mesa. Finally, Section 4 provides a simple example of Cypress use. We cover onlythe abstract model and the DB interface, not its implementation or rationale. The reader interestedin these should consult CSL Report 83-4. A set of formal axioms for the model can also be foundthere.Clients interested in tools for examining or modifying databases, either as an end-user or fordebugging an application program, should consult the database tools documentation:[Indigo]Documentation> SquirrelDoc.tioga, .press.HYfp \Tq XxpS VD= TM QO O2 K&< Ir pK GbD E-M B#A ?T <F : X 8R 6K 2p^ 0; F .; -=:K TIMESROMAN  TIMESROMAN  TIMESROMAN jj/OCypressDoc1.bravoCattellJune 15, 1983 9:44 AM