Implementation of procedures in a database programming language

This thesis documents the design and implementation of procedures in a database programming language. The purpose of this thesis is to integrate procedure facilities into an existing relational database system.A relation is defined over a set of attributes. Given the values of a subset of attributes as input, a selection operation looks up the relation and outputs the values of the remaining attributes. Our proposed procedure construct supports this concept: a procedure is defined over a set of parameters, and the procedure can be invoked with different subsets of input parameters. This is accomplished by allowing procedures to have a sequence of blocks within the procedure body. Each block abstracts a sequence of actions which requires a subset of parameters as input. Users can select different blocks to be activated by supplying different subsets of input parameters. While a relation can be selected with any subset of input attributes, a procedure can only be invoked with defined subsets of parameters.Our proposed procedures also support the usual properties of procedural abstraction: encapsulation and parameterization. A procedure declaration defines the procedure name, formal parameters, and the body. Procedure invocation is through the use of a stand-alone procedure call statement which specifies the procedure name and a list of actual parameters. Before a procedure is activated, the formal parameters within the procedure body are replaced by the corresponding actual parameters. Moreover, a procedure can be printed, shown, deleted, called by itself or other procedures, and passed as a parameter