Managing the log and the bootstrap data set

The DB2® log registers data changes and significant events as they occur. The bootstrap data set (BSDS) contains information about the data sets that contain the log. You can perform a variety of tasks to ensure that DB2 logging satisfies the needs of your environment.

About this task

DB2 writes each log record to a disk data set called the active log. When the active log is full, DB2 copies its contents to a disk or tape data set called the archive log. That process is called offloading.

  • How database changes are made
    Before you can fully understand how logging works, you need to be familiar with how database changes are made to ensure consistency.
  • How DB2 retrieves log records
    Normal DB2 operation and recovery tasks rely on the availability of log records. DB2 retrieves log records from different sources, depending on the situation.
  • Managing the log
    You can control and monitor log activity by using several DB2 commands and a utility.
  • What to do when RBA or LRSN limits are reached
    Before a DB2 subsystem or data sharing group reaches the end of the log RBA or LRSN range, you must reset the log RBA value. The process that you use to reset the log RBA value depends on whether the DB2 subsystem is the member of a data sharing group or in a non-data sharing environment.
  • Canceling and restarting an offload
    If the offload task remains stalled, the active logs eventually become full and DB2 stops database update activity.
  • Displaying the status of an offload
    You can use the DISPLAY LOG command to view information about the current active log data sets and status of the offload task.
  • Discarding archive log records
    You must keep enough log records to recover units of work and databases.
  • Locating archive log data sets
    To ensure that you can recover your data in the event of a failure, you need to locate archive log data sets.
  • Management of the bootstrap data set
    The bootstrap data set (BSDS) is a VSAM key-sequenced data set that contains information about the log data sets and the records that those data sets include. The BSDS also contains information about buffer pool attributes.
Parent topic: Operation and recovery

Related information

Reading log records