An explicit journaling option on the ckpdb command causes the checkpoint to be taken offline and with an exclusive lock on the database.

The first time journaling is turned on in a particular database, you must checkpoint the database with journaling enabled (ckpdb +j dbname). Doing so ensures that the checkpoint is taken offline.

Once you have enabled journaling by checkpointing offline with the +j option, you can maintain the “journaling on” status and take online checkpoints by not subsequently setting the +j option when you take a checkpoint. Online checkpoints permit users to continue using the database while the checkpoint is being taken.

After you have enabled journaling for the database by checkpointing offline with the +j option, you can take an offline checkpoint to start journaling of tables for which journaling is enabled after the next checkpoint.