About circular, linear, and archive logging

One of three logging styles can be selected for all logged databases: circular, linear, or archive. When you enable circular-style logging, the transaction log extents are reused as the size limit of the log file is reached. The reuse saves resources, but limits your recovery options. Transaction log extents are not backed up by database agent when circular-style logging is enabled. Therefore, you can only recover logged Lotus Notes databases to the point in time when the transaction log extents were overwritten.

When you enable linear-style logging, the transaction log extents function the same as for circular-style logging, with one exception. With circular-style logging, the size of the transaction log extents are predefined and limited. For linear-style logging, the size of the transaction log extents is user defined and limited in size only by the amount of mass storage available.

When you enable archive-style logging, transaction log extents are generated as needed and are limited in number only by the capacity of your mass storage. Archive-style transaction log extents must be backed up, unlike circular-style and linear-style transaction log extents, which cannot be backed up. They can be used as the incremental backup for all logged databases. Backups of the archive-style transaction log extents ensure that the transaction log extents are marked as available to be recycled. These backups also prevent your mass storage from filling up. Unlike circular-style and linear-style logging, archive-style logging does not limit the point in time to which a database can be recovered. With archive-style logging enabled, a logged database can be recovered to any point in time. This time can be any time between when the database itself was last backed up to the current time.