Using the Indexed Sequential Access Method

This topic covers the following subtopics.

Topic
Using the Basic Indexed Sequential Access Method (BISAM)
Using the Queued Indexed Sequential Access Method (QISAM)
Processing ISAM Data Sets
Organizing Data Sets
Creating an ISAM Data Set
Allocating Space
Calculating Space Requirements
Retrieving and Updating
Adding Records
Maintaining an Indexed Sequential Data Set

Note: z/OS no longer supports indexed sequential (ISAM) data sets. Before migrating to z/OS V1R7, convert your indexed sequential data sets to key sequenced data sets (KSDS). To ease the task of converting programs from ISAM to VSAM, consider using the ISAM interface for VSAM. See Using ISAM Programs with VSAM Data Sets. The ISAM interface requires 24-bit addressing.

This topic is written as if you were using ISAM to access real ISAM data sets. Some parts of this topic describe functions that the system no longer supports. Using ISAM Programs with VSAM Data Sets clarifies this topic.