The Optimization Of VSAM File Performance

Because of its advantage in computing capability, usability, security and other expanded functions, the mainframe holds the market with advanced server. That is the reason why multinational banks, insurance agencies and telecommunication companies preferred to use it. But due to the expensive purchasing cost and some problems with the research and development environment only a number of people can access and make use of mainframe. This makes mainframe a mysterious thing.Virtual Storage Access Method (VSAM), being the most important file storage access method used in mainframe, performs well than any other access method. VSAM is a kind of file which use the virtual storage access method, it belongs the second phase of the development of data management technology. Take the bank operation for instance, the data is huge, and need to read or write a great deal of VASM files everyday, each file has millions of records, so the speed of reading and writing the VSAM file is related to the performance of the whole system. According to this, it is necessary to research the VSAM file and optimize its performance.In this thesis, I will be explaining what is VSAM, its basic knowledge, including the structure of VSAM file, several kind of VSAM files, the principle of VSAM file, the space allocation of VSAM dataset and the principle of allocation. According to the practical project, do some research on the VSAM configuration attributes, introducing the application environment, the basic operationdesign testing program, compare testing result and even provide some advices on how to optimize its performance.