The default values for checkpoint time and recovery time are sufficient and in most cases do not need to be changed.
The time between checkpoints defaults to 60 minutes.
You can adjust the time between checkpoints when you start your server by changing the -gc and -gr options in the start_iq command or in the dbname.cfg configuration file. The -gc switch specifies the number of minutes for the checkpoint timeout period. The -gr switch specifies the number of minutes for the maximum recovery time. The database engine uses both switches to calculate the checkpoint time.
For details on start_iq database options, see the Utility Guide.