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 method and system are provided for maintaining a database index version. The database index includes a secondary node affiliated with each leaf node of the index. The secondary node stores version information for each leaf node. A pointer in a header section of the leaf node connects the leaf node to the secondary node. In addition, a status list is maintained to identify each transaction. At such time as a scan of a database index is conducted and an index item is returned, a computation is conducted using the transaction identifiers in the secondary node, the delete flag in the leaf node, and the status list contents for the scanning transaction. The computation and associated logic will determine whether to accept or reject an item. The method results in returning a correct version of the item as existed at the time of start of the scanning transaction.

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: A method for crash recovery in a data base management system (DBMS). A plurality of pages of data are loaded sequentially as a block from a fast recovery log into a bufferpool, wherein these pages have respectively been pre-stored into the fast recovery log to construct the block. A plurality of logical operations are then applied from a logical log to the pages in the bufferpool to return the DBMS to a transactionally consistent state.

Abstract: A system, computer usable medium and computer-based method for improved data sharing within a cluster of nodes having a database management system. The method defines a virtual replicated table as being useable in a hybrid of a shared-cache and shared-nothing architecture. The virtual replicated table is a physically single table sharable among a plurality of cluster nodes for data read operations and not sharable with other cluster nodes for data modification operations. Default owner node is assigned for each virtual replicated table to ensure the page validity and provide requested pages to the requesting node.

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.