Dynamic log allocation

Dynamic log allocation prevents log files from filling and hanging the system during long transaction rollbacks. The only time that this feature becomes active is when the next log file contains an open transaction. (A transaction is long if it is not committed or rolled back when it reaches the long-transaction high-watermark.)

The database server automatically (dynamically) allocates a log file after the current log file when the next log file contains an open transaction. You can use dynamic log allocation for the following actions:
  • Add a log file while the system is active
  • Insert a log file after the current log file
  • Immediately access new log files even if the root dbspace is not backed up
The best way to test dynamic log allocation is to produce a transaction that spans all the log files and then use onstat -l to check for newly added log files. For more information, see Allocate logical log files.
Important: You still must back up log files to prevent them from filling. If the log files fill, the system hangs until you perform a backup.

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