num_log_span - Number log span configuration parameter
This parameter specifies whether there is a limit to how many log files one transaction can span, and what that limit is.
- Configuration type
- Parameter type
- Configurable online
- Configurable by member in a Db2® pureScale® environment
- Propagation class
- Default [range]
- 0 [0 - 65 535]
- Unit of measure
If the value is not 0, this parameter indicates the number of active log files that one active transaction is allowed to span.
If the value is set to 0, there is no limit to how many log files one single transaction can span.
If an application violates the num_log_span configuration, the application is forced to disconnect from the database and the transaction is rolled back.
This parameter, along with the max_log configuration parameter, can be useful when enabling infinite active logspace. If infinite logging is on (that is, if logsecond is set to -1) then transactions are not restricted to the upper limit of the number of log files (logprimary + logsecond). When the value of logprimary is reached, Db2 starts to archive the active logs, rather than failing the transaction. This can cause problems if, for example, an application contains a long running transaction that is left uncommitted. If this occurs, the active logspace continues to grow, possibly leading to poor crash recovery performance. To prevent this, you can specify values for one or both of the max_log or num_log_span configuration parameters.
- ARCHIVE LOG
- BACKUP DATABASE
- RESTORE DATABASE
- ROLLFORWARD DATABASE