IBM Mainframe Forum

Hi All,

What is meant by BDAM datasets? where we will be using that What is the difference between BDAM and VSAM datasets. Any idea please

Basic Direct Access Method allows you to read or write a block of data anywhere in the file -- you do not have to read the previous data as with a sequential file. The equivalent VSAM format is RRDS. A BDAM file is completely unstructured, unlike the VSAM file which has a structure superimposed upon it. The BDAM file is typically used with a hash to determine which block to read (or write), is preformatted so every block is available for use, and is rarely used these days (although some vendor programs still use BDAM files).