Thanks Dick. The thought is that keeping them in memory rather than in a VSAM file should make the response time smaller. As suggested above, I am exploring the option to load into Common Work Area (CWA) using a PLT-program.
At the same time, I was also exploring of using a VSAM file but defining it as a CICS data table. Should that be an efficient solution ? Because data table is loaded from the source VSAM dataset and CICS file reads would take data from the data table in memory rather than from the DASD.