PL/I supports workstation VSAM sequential, keyed, and direct data sets. These correspond to PL/I consecutive, indexed, and relative data set organizations, respectively.
Both sequential and keyed access are possible with all three types of data sets. With keyed data sets, the key, which is part of the logical record, is used for keyed access; keyed access is possible for direct data sets using relative record numbers. Keyed access is also possible for sequential data sets using the sequential record value as a key.
All workstation VSAM data sets are stored on direct-access storage devices. The physical organization of workstation VSAM data sets differs from those used by other access methods.