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.
About this task
Log records are retrieved by Db2 through the following events:
- A log record is requested using its RBA.
- Db2 searches
for the log record in the following locations in the order in which
they are presented:
- The log buffers.
- The active logs. The bootstrap data set registers which log RBAs apply to each active or archive log data set. If the record is in an active log, Db2 dynamically acquires a buffer, reads one or more CIs, and returns one record for each request.
- The archive logs. Db2 determines which archive volume contains the CIs, dynamically allocates the archive volume, acquires a buffer, and reads the CIs.