Continuous Nocontinuous Causes the LogMiner process to attach to the database and begin extracting records in "near-real" time. When the Continuous qualifier is specified, the RMU Unload After_Journal command extracts records from the online after-image journal files of the database until it is stopped via an external source (for example, Ctrl/y, STOP/ID, $FORCEX, or database shutdown). A database must be explicitly enabled for the Continuous LogMiner feature. To enable the Continuous LogMiner feature, use the RMU Set Logminer command with the Enable and Continuous qualifiers; to disable use of the Continuous LogMiner feature, use the RMU Set Logminer command with the Enable and Nocontinuous qualifiers. The output from the Continuous LogMiner process is a continuous stream of information. The intended use of the Continuous LogMiner feature is to write the changes into an OpenVMS mailbox or pipe, or to call a user-supplied callback routine. Writing output to a disk file is completely functional with the Continuous LogMiner feature, however, no built-in functionality exists to prevent the files from growing indefinitely. It is important that the callback routine or processing of the mailbox be very responsive. If the user-supplied callback routine blocks, or if the mailbox is not being read fast enough and fills, the RMU Unload After_Journal command will stall. The Continuous LogMiner process prevents backing up the after-image journal that it is currently extracting along with all subsequent journals. If the Continuous LogMiner process is blocked from executing for long enough, it is possible that all available journals will fill and will not be backed up. When a database is enabled for the Continuous LogMiner feature, an AIJ "High Water" lock (AIJHWM) is utilized to help coordinate and maintain the current .aij end-of-file location. The lock value block for the AIJHWM lock contains the location of the highest written .aij block. The RMU Unload After_Journal command with the Continuous qualifier polls the AIJHWM lock to determine if data has been written to the .aij file and to find the highest written block. If a database is not enabled for the Continuous LogMiner feature, there is no change in locking behavior; the AIJHWM lock is not maintained and thus the Continuous qualifier of the RMU Unload After_Journal command is not allowed. In order to maintain the .aij end-of-file location lock, processes that write to the after-image journal file must use the lock to serialize writing to the journal. When the Continuous LogMiner feature is not enabled, processes instead coordinate allocating space in the after-image journal file and can write to the file without holding a lock. The Continuous LogMiner process requires that the AIJHWM lock be held during the .aij I/O operation. In some cases, this can reduce overall throughput to the .aij file as it serves to reduce multiple over-lapped I/O write operations by multiple processes. The Save_Metadata and Restore_Metadata qualifiers are incompatible with the Continuous qualifier.