Example of a well-organized database

Keeping your databases well-organized is more important to the processing of OSAM sequential buffering (SB) than selecting the right number of SB buffer sets.

When the databases SB processes are well organized, you note elapsed time improvements. This is because your programs process IMS database segments and records, and they do not process DASD blocks directly. Processing a well-organized database in logical-record sequence results in an I/O reference pattern that accesses most DASD blocks in physical sequence. SB can take advantage of these sequential I/O patterns by issuing many sequential reads. Extensive use of sequential reads considerably reduces the elapsed time for your job.