Abstract: A minimized journaling mechanism stores minimized journal data in a format that allows for display and outputting the journal data in human-readable form. When a change to a record occurs, instead of writing only the changed bytes, all of the bytes in each field that changed are written to the journal, along with all of the bytes in each field selected to be always journaled. A default object is created with default data in all of the fields. When the journal entry needs to be output in human-readable form, the default object is read, and the minimized journal entry is then overlaid on the default object. The result is an object that contains default data in all non-selected fields that were not changed, with the journal data in all fields and that did change and in all fields that were selected to always be journaled.

Abstract: A database manager selectively caches journal entries for certain database changes based on dynamic selection criteria. Preferably, a journal disk drive is provided for storing changes to the database. Database change entries are sequentially cached in a main memory journal buffer, a waiting journal write. When a buffer is filled, its buffer contents are written to the journal disk. However, certain change operations will cause the contents of the buffer to be written to the journal disk immediately, before filling the buffer. Certain database change entries selectively cause the buffer to be written, depending on dynamic selection criteria. Preferably, these selection criteria take into account both the estimated time to recover in the event of a system crash and the current level of activity on the system. Generally, the busier the system, the more data will be cached, and vice versa.