DYNAMIC_LOGS configuration parameter

Use the DYNAMIC_LOGS configuration parameter to allow logical logs to be dynamically added when necessary to prevent transaction blocking.

onconfig.std value
0 = Turn off dynamic-log allocation.

1 = Set off the “log file required” alarm and pause to allow manual addition of a logical-log file. You can add a log file immediately after the current log file or to the end of the log file list.

2 = Turn on dynamic-log allocation. When the database server dynamically adds a log file, it sets off the “dynamically added log file” alarm.

takes effect
For HDR: when the database server is shut down and restarted
For Enterprise Replication: when Enterprise Replication is started
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.


If DYNAMIC_LOGS is 2, the database server automatically allocates a new log file when the next active log file contains an open transaction. Dynamic-log allocation prevents long transaction rollbacks from blocking transactions.

If you want to choose the size and location of the new logical-log file, set DYNAMIC_LOGS to 1. Use the onparams -a command with the size (-s), location (-d dbspace), and -i options to add a log file after the current log file.

If the value of the DYNAMIC_LOGS configuration parameter is 0 and transaction blocking occurs, shut down the database server, set DYNAMIC_LOGS to 1 or 2, and then restart the database server.
Important: If you are using Enterprise Replication with dynamic log allocation, set LTXEHWM to no higher than 70.

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