Sequential processing only: HSAM

HSAM is a hierarchic access method that can handle only sequential processing. You can retrieve data from HSAM databases, but you cannot update any of the data. The z/OS® access methods that HSAM can use are QSAM and BSAM.

HSAM is ideal for the following situations:

You are using the database to collect (but not update) data or statistics.
You only plan to process the data sequentially.

HSAM characteristics

HSAM stores database records in the sequence in which you submit them. You can only process records and dependent segments sequentially, which means the order in which you have loaded them. HSAM stores dependent segments in hierarchic sequence.

An overview of how HSAM works

This topic contains Diagnosis, Modification, and Tuning information.

HSAM databases are very simple databases. The data is stored in hierarchic sequence, one segment after the other, and no pointers or indexes are used.