Largest size for Datacom database files
Article ID: 93149
Updated On:
Products
Issue/Introduction
What is the largest or maximum file allocation size for a data or index area in Datacom?
Environment
Component : Datacom/AD
Component : Datacom/DB
Resolution
When allocating files using the legacy EXCP method, each application database file is a standard sequential (PS) file, subject to the same rules as any other PS file.
As a DSNTYPE=BASIC type file, it is limited to 16 extents per volume, and no more than 65535 tracks on one volume. This file can be allocated on as many as 59 volumes if needed. If more than 65535 tracks are needed on a volume, allocating the file with DSNTYPE=LARGE will allow up to 16,777,215 tracks on a single volume.
Datacom does not support Extended Format files, but using DSNTYPE=LARGE should meet most application needs.
Additional Information
For more information about file allocations and limits, please see the IBM DFSMS Using Data Sets manual:
- For z/OS 3.1, https://www.ibm.com/docs/en/zos/3.1.0?topic=dfsms-zos-using-data-sets
- For z/OS 2.5, https://www.ibm.com/docs/en/zos/2.5.0?topic=dfsms-zos-using-data-sets
- For z/OS 2.4, https://www.ibm.com/docs/en/zos/2.4.0?topic=dfsms-zos-using-data-sets
- For z/OS 2.3, https://www.ibm.com/docs/en/zos/2.3.0?topic=dfsms-zos-using-data-sets
- For z/OS 2.2, https://www.ibm.com/docs/en/zos/2.2.0?topic=dfsms-zos-using-data-sets
- For z/OS 2.1, https://www.ibm.com/docs/en/zos/2.1.0?topic=dfsms-zos-using-data-sets
Also see the Datacom documentation section Datacom Database Limits Quick Reference.
As always, please contact Broadcom support for Datacom if you have further questions.
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