Abstract: Database tables which are to be loaded with large data objects are defined with a special logging attribute that causes the associated database management system to suspend recovery logging for the databases so defined, but to continue with logging control information, such as space management changes. During a two-phase commit operation for a database transaction in a distributed system, at each database all modified data pages are written to disk before the end of the phase 1 commit, if the pages have not been previously written. This and other write operations are monitored for errors. If any of the changed data pages cannot be written to disk successfully before the end the phase 1 commit operation, then the transaction is rolled back at all databases.

Abstract: Database tables which are to be loaded with large data objects (LOBs) are defined with a special logging attribute value. This attribute value causes the database management system to suspend recovery logging for the databases so defined, but to continue with the logging of control information, such as space management changes. Certain control information recovery log entries have a special status indicator. For LOBs, this status indicator is set to cause the associated LOB entry to be marked as invalid when the log entry is reapplied, for example, during a recovery operation from a media failure. Rather than invalidating the entire table, the database management system will only prevent access to the entries which have been invalidated during the recovery process.

Abstract: A method, apparatus, and article of manufacture for accessing a row in a database. In accordance with the present invention, the database is stored on a data storage device connected to a computer. An identification number is generated for a region, wherein the identification number associated with the region reflects row movement in the region. The identification number is updated when there is row movement in the region. When accessing a row in the region, whether to perform a direct row access is determined based on the identification number.

Abstract: The present invention discloses a method, apparatus, and article of manufacture for generating a row identification number within a computer. In accordance with the present invention, the row identification number is associated with a row in a database. The database is stored on a data storage device connected to a computer. A unique row identification number is created by using a computer-dependent timestamp. The unique row identification number is manipulated so that the row identification number is quasi-random.

Abstract: A method, apparatus, and article of manufacture for a computer implemented technique for deferring large object access with intermediate results. A query is executed in a database stored on a data storage device connected to a computer. A control structure representing an expression in the query is generated. An intermediate result is generated by retrieving data for the query that is not represented by the control structure. Then, a result table is built using the processed intermediate result and the control structure.

Abstract: Two methods for resolving locking contention for pseudo-deadlocked transactions without rolling back or aborting any of the deadlocked transactions are provided. In one method, one or more shared lock requests from deadlocked transactions are granted ahead of at least one exclusive lock request from a deadlocked transaction. In another method, all shared lock requests from deadlocked transactions are granted ahead of all exclusive lock requests from deadlocked transactions.

Abstract: A two-pass method for relocating a set of linked control blocks stored away on a persistent medium after a first pass and then rewritten into internal memory of a computing facility during second and subsequent passes each time an application to which the control blocks are bound is executed. The first pass involves path following and coloring pointers affected by the relocation, mapping discontiguously located blocks into a linear address space, changing affected control blocks to location offsets, and writing out the linked control blocks to DASD store. Upon the second pass, virtual addresses are substituted for the offsets upon rewriting of the control blocks to internal memory.