Abstract: A system for data base management using memory devices holding a database containing tables of data occupying extents. A database engine reviews each query to determine an extents list of extents containing the data needed by that said query. A query monitor then re-orders the extents lists so that extents are retrieved and stored in a buffer cache for more efficient use when executing the queries. The database engine retrieves needed extents from the memory devices, as ordered in the extents lists, and stores those extents in the buffer cache. The database engine then executes one or more queries on the data in the extents in the buffer cache to determine respective results.

Abstract: A tool and method for integrating manual instructions of a database query plan with a database optimizer. The tool may be in the form of an editor to receive manual instructions associated with selection of database objects such as tables and operations associated with the objects. The editor may consult with the database optimizer prior to submitting query plan execution instructions. The consultation may result in the optimizer providing alternatively available selections to the editor and/or a cost estimate for selected operations and/or automatic selection of operators to complete a plan that has been partially constructed or edited manually. Following completion of the query plan, the editor may submit the query plan to the optimizer for execution and/or save the plan for use in future execution(s) of the query.

Abstract: A data processing implemented method and system and article of manufacture are provided for determining compatibility between a primary instance and a standby instance, the primary instance being characterized by a first log position indicator and a primary log chain fingerprint (FP-P) and the secondary instance being characterized by a second log position indicator and a secondary log chain fingerprint (FP-S); the FP-P and the FP-S each uniquely identifying a prescribed history of an associated data processing system.

Abstract: A log-shipping data replication system employs a primary server coupled to a standby server. In operation, the primary server concurrently flushes log data at the primary server and transmits the same log data from the primary server to the standby server. The primary server further transmits at least one buffer flush boundary indication to the standby server indicating the flushing status of the log data at the primary server. The standby server processes the log data as a function of receiving the log data from the primary server, and/or receiving the at least one buffer flush boundary indication from the primary server.

Abstract: A system for limiting the amount of time for a database server to perform a crash recovery process. A maximum recovery time for the database server to perform the crash recovery process is specified. An estimated recovery time for the crash recovery process that is less than the maximum recovery time is calculated, based on at least one of a deterministic analysis of cost accumulation during prior instances of the crash recovery process or an empirical analysis of cost accumulation during regular transaction processing in the database server. The crash recovery process is then conformed to the estimated recovery time.

Abstract: A method and system are provided for providing a consistent reintegration of a failed primary instance as a new secondary instance with implementation of truncation of log records. Upon failure of a primary instance, a secondary instance may be reassigned as the new primary instance. Prior to reintegration, any portion of the database log of the failed primary that is after the log position of the new primary instance may be truncated, followed by a comparison of the log positions of both the new primary instance and the new secondary instance. In limited circumstances, the truncation of the log data generated by the failed primary instance after the point of failure is possible, and supports reintegration of the failed primary as a new secondary instance with limited overhead.

Abstract: Sending log records from a first system instance's log buffer to a second system instance is disclosed. Both instances may be instances of a database system. A method may create a log record within the buffer. The record contains actual log information, such as descriptions of transactions. A flag corresponding to the record is set in memory other than the buffer. The flag indicates whether the record has been sent to the second instance, and/or whether the second instance has received the record. The method may further embed non-log information within a simulated log record having a format identical to the log record's format. The non-log information, which may not include actual transactions to be committed, is embedded in a body section of the simulated record. At least one otherwise unused bit of a metadata section of the simulated record is set, indicating that the simulated record is simulated.

Abstract: A system for data base management using memory devices holding a database containing tables of data occupying extents. A database engine reviews each query to determine an extents list of extents containing the data needed by that said query. A query monitor then re-orders the extents lists so that extents are retreived and stored in a buffer cache for more efficient use when executing the queries. The database engine retreives needed extents from the memory devices, as ordered in the extents lists, and stores those extents in the buffer cache. The database engine then executes one or more queries on the data in the extents in the buffer cache to determine respective results.