Non-VSAM data sets are collections of fixed-length or variable-length records, grouped into blocks. To access non-VSAM data sets, use BSAM, QSAM, or BPAM. There are several types of non-VSAM data sets:

Sequential data set (PS)

Contains records that are stored in physical order. New records are appended to the end of the data set. You can specify a sequential data set in extended format.

Partitioned data set (PDS)

Contains a directory of sequentially organized members, each of which can contain a program or data. After opening the data set, you can retrieve any individual member without searching the entire data set.

Partitioned data set extended (PDSE)

Contains an indexed, expandable directory of sequentially organized members, each of which can contain a program or data. You can use a PDSE instead of a PDS. The main advantage of using a PDSE over a PDS is that a PDSE automatically reuses space within the data set.