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: The disclosure and claims herein are directed to efficient journaling for recovery of a database index by journaling zones of a page. A journal mechanism maintains a page zone bit map that includes a bit for a plurality of zones in each page to indicate which zones have had their unchanged image journaled before being changed since a last sync point update. The page zone bit map has a bit for each zone in each page so that the status of each zone can be tracked separately. Tracking the smaller zones of the pages makes the process more efficient both at run time and during recovery by reducing the period of time for memory deposits and reducing the amount of total redundant/recovery data sent to disk for larger pages.

Abstract: The disclosure and claims herein are directed to efficient journaling for recovery of a database index by journaling zones of a page. A journal mechanism maintains a page zone bit map that includes a bit for a plurality of zones in each page to indicate which zones have had their unchanged image journaled before being changed since a last sync point update. The page zone bit map has a bit for each zone in each page so that the status of each zone can be tracked separately. Tracking the smaller zones of the pages makes the process more efficient both at run time and during recovery by reducing the period of time for memory deposits and reducing the amount of total redundant/recovery data sent to disk for larger pages.

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 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 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: The disclosure and claims herein are directed to efficient journaling for recovery of a database index by journaling zones of a page. A journal mechanism maintains a page zone bit map that includes a bit for a plurality of zones in each page to indicate which zones have had their unchanged image journaled before being changed since a last sync point update. The page zone bit map has a bit for each zone in each page so that the status of each zone can be tracked separately. Tracking the smaller zones of the pages makes the process more efficient both at run time and during recovery by reducing the period of time for memory deposits and reducing the amount of total redundant/recovery data sent to disk for larger pages.

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 method, apparatus, system, and signal-bearing medium that in an embodiment determine, after a restore of a version of an object, where to begin applying changes from a change log to the object based on an identification in the saved version of the object. When a save command for an object is received, an identification of the change log entry associated with the save command is stored in the saved version of the object. Changes to the object then continue to be logged to the change log. After the saved version of the object is restored, the identification in the saved version of the object is used to find the change log entry at which to start applying changes from the change log to the object. In this way, the point in the change log at which to start applying changes to the object may be determined based on the saved version of the object. In an embodiment, this allows the object to continue to be accessed while the save operation is performed.

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 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 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: An index recovery mechanism recovers all indexes that were journaled and may be fully recovered during IPL. In addition, the index recovery mechanism performs a first stage of processing for any index that was journaled but cannot be fully recovered during IPL. The first stage processing includes storing index recovery data for an index during IPL. Once IPL is complete, the index recovery mechanism performs a second stage of processing by reading the index recovery data that was stored during IPL, and completing recovery of the index. By performing this two-stage index recovery, the first stage during IPL and the second stage post-IPL, indexes that cannot be fully recovered during IPL can still be journaled and recovered.

Abstract: An apparatus and method includes a database journal that records journal entries. Each journal entry includes a validation value that is computed from the data and metadata for the record before it is changed. In this manner, journal entries may be applied with confidence to a record in a database. This is especially useful when minimized data journal entries are used. If the validation value of the journal entry matches the validation value computed from the data and metadata of the record that the journal entry is to be applied to, then the record before applying the journal entry is identical to the record in the original database, and the journal data may be applied to the database record. If the validation value of the journal entry does not match the validation value computed from the data and metadata of the record that the journal entry is to be applied to, the record is not the same as in the original database when the journal entry was generated.

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, awaiting 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.

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.

Abstract: An apparatus, program product and method manage a queue through the use of element-based journaling to record changes made to logical elements in a queue. In contrast to convention memory-based journaling, where any changes to the memory representing an element in a queue are journaled, only those operations that affect the logical ordering and/or placement of an element on a queue, or the logical contents of such an element, are journaled. Memory management operations such as pointer manipulation operations that modify pointers or other memory management data, but do not otherwise modify the actual elements in a queue or their relative ordering, need not be journaled. As a consequence, the storage and processing overhead associated with journaling may be substantially reduced, thereby substantially reducing the overhead associated with maintenance and recovery of a queue.

Abstract: An apparatus and method includes a database journal that records journal entries. Each journal entry includes a validation value that is computed from the data and metadata for the record before it is changed. In this manner, journal entries may be applied with confidence to a record in a database. This is especially useful when minimized data journal entries are used. If the validation value of the journal entry matches the validation value computed from the data and metadata of the record that the journal entry is to be applied to, then the record before applying the journal entry is identical to the record in the original database, and the journal data may be applied to the database record. If the validation value of the journal entry does not match the validation value computed from the data and metadata of the record that the journal entry is to be applied to, the record is not the same as in the original database when the journal entry was generated.