Mainframe: Check Points in DB2

DB2 Primary Key
DB2 Primary Key

Mainframe programmers do not aware about there is checkpoints concept in DB2. Many guys assume that CHECKPOINT concepts is present only in IMS DB.

Let us see, which option in DB2 stores checkpoints. There is a “CHEKFREQ=” option. This option stores how many check points db2 has taken or as time duration.

  • DB2 checkpoints are controlled using DSNZPARM and CHKFREQ. The CHKFREQ parameter is the number of minutes between checkpoints for a value of 1 to 60 or the number of log records written between DB2 checkpoints for a value of 200 to 16,000,000.
  • The default value is 500,000. You may need different settings for this parameter depending on your workload. For example, you may want it higher during batch processing.
  • CHKFREQ is a hard parameter to set because it requires a bounce of the DB2 subsystem to take effect. Use the SET LOG CHKTIME command to dynamically set the CHKFREQ parameter.

Online CICS programs-During online processing, DB2 should checkpoint about every 5 through 10 minutes.


Author: Srini

Experienced software developer. Skills in Development, Coding, Testing and Debugging. Good Data analytic skills (Data Warehousing and BI). Also skills in Mainframe.