Virtual Storage Access Method. Access Method Interface between application program and Operating System Facilitates data access VSAM Most widely used access method on IBM mainframes Designed to operate in a virtual storage environment Handles all I/O requests to Operating System
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
ICF - The relationships among the master catalog, user catalogs, and data sets
Records are grouped together in control intervals, and control intervals are grouped together in control areas
The structure of a control interval – for fixed length records 10 bytes is reserved for Control Information
Match your record size to valid sizes for control intervals – that will maximize storage efficiency
Need to Insert record 6047
Need to insert record 6046 ??
VSAM will split the control area if needed
Records are always kept in physical sequence
Access Method Services