Research On Stored Procedure In DBMS Based On Interpreter

With the deepening society information, national database Shenzhou OSCAR is widely applied in many different industries. In the meanwhile, the users have increasingly high demands to DBMS. Compared to international mainstream DBMS, Shenzhou OSCAR has a long way to go and urgently needs function expansion and upgrade. SP (Stored Procedure) plays an important role in DBMS. Through SP, some application logic can be transferred from customer side to server side. At the same time, the encapsulation of stored procedure achieves modularization, thus the efficiency of application system development is improved.Focusing on the subject of "Shenzhou OSCAR stored procedure", this paper puts forward a realizing method of SP based on interpreter.SP language PLOSCAR realizes the combination of process control sentence with SQL sentence, which not only has the power of SQL language accessing relation database, but also the process of module language. Due to characteristics of stored procedure language, this paper firstly discusses the realization methods. On the basis of OSCAR system achitechture, it sets PLOSCAR design principles and goals and gives the general design of PLOSCAR based on interpreterGenerally speaking, PLOSCAR is made up of two parts, pre-compilation when creation and explanation execution. This article introduces several crucial technologies in PLOSCAR realization. In order to achieve database inner storage of stored procedure, it enriches system tables. It solves the nested scope of PLOSCAR's variables and practical visibility with dynamic and static symbol tables during the process of lexical and syntax analysis. In order to realize loose coupling of modules, different processing method in SQL sentence and module sentence is adopted during compilation and explanation execution period; the realization of function overloading in stored procedure; in order to improve efficiency in execution process, the concept of buffer pool of stored procedure is introduced.Finally, on the basis of realized stored procedure, the performance test is made and it shows that the stored procedure design reaches the goal and the DBMS performance is improved.