Abstract: A mechanism is provided for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, and releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Abstract: A mechanism is provided for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, and releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Abstract: A mechanism for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Abstract: Techniques are disclosed for synchronizing a primary data system with an auxiliary data system that processes data for the primary data system. In one embodiment, how current the primary data system and the auxiliary data system are is determined. Requests sent from the primary data system that were not processed by the auxiliary data system are determined. The requests are resent to the auxiliary data system for processing.

Abstract: A method and system for providing convergence of data copies in asynchronous data replication in a database system, includes: labeling rows, a copy of identification and propagation controls. In applying communicated changes, conflicting changes are identified and resolved. In this manner, convergence of data copies in asynchronous data replication is provided, and processing and storage costs are significantly reduced.

Abstract: A computer readable medium encoded with a computer program for handling transaction messages in asynchronous data replication in a database system is disclosed. The computer program provides a high speed parallel apply of transactional changes to a target node such that the parallel nature of the application of changes does not compromise the integrity of the data. The computer program detects, tracks, and handles dependencies between transaction messages to be applied to the target node. If a transaction message has a dependency on one or more preceding transaction messages whose applications have not yet completed, that transaction message is held until the application completes. In addition, the computer program requires significantly less overhead than conventional approaches.

Abstract: Provided are techniques for partitioning a physical index into one or more physical partitions; assigning each of the one or more physical partitions to a node in a cluster of nodes; for each received document, assigning an assigned-doc-ID comprising an integer document identifier; and, in response to assigning the assigned-doc-ID to a document, determining a cut-off of assignment of new documents to a current virtual-index-epoch comprising a first set of physical partitions and placing the new documents into a new virtual-index-epoch comprising a second set of physical partitions by inserting each new document to a specific one of the physical partitions in the second set using one or more functions that direct the placement based on one of the assigned-doc-id, a field value derived from a set of fields obtained from the document, and a combination of the assigned-doc-id and the field value.

Abstract: Database management systems, methods, and program products that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

Abstract: Database management systems and program products that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

Abstract: Systems, methods and articles of manufacture are disclosed for synchronizing a primary data system with an auxiliary data system that processes data for the primary data system. In one embodiment, how current the primary data system and the auxiliary data system are may be determined. Requests sent from the primary data system that were not processed by the auxiliary data system may be determined. The requests may be resent to the auxiliary data system for processing.

Abstract: An information retrieval system and method are provided for minimizing the number of blocks searched in a cell before recording a new record in the table and determining which block can be assigned if a table has space available to store a new record in the case an additional block should be associated with a cell. Dimensions for a table are identified, and at least one block in the table is associated with a dimension value for each dimension, where each block comprises contiguous storage pages. The block can be further associated with a cell; this associated cell has a unique combination of dimension values comprising an dimension value for each of the dimensions. A unique associated bit list for each dimension value for each dimension has a unique corresponding list entry for each block associated with that dimension value, and a unique associated bit list for each cell has a unique corresponding list entry for each block associated with that cell.

Abstract: A method masking data failures, when a master copy of data is unavailable comprises storing a single master copy of data and a replica copy of the data; writing to the master using a middleware component; and reading from either the master or the replica using the middleware component, when the master copy is unavailable. When the master is unavailable, the writes are stored in a table located in the middleware component as stored write requests, in which the stored write requests comprise UDI's to be made to the master. The reads are also performed from the table and the replica when the master is unavailable. When the master becomes available, the stored write requests are propagated to the master. Thus, the middleware allows the writes to run during times when the master is unavailable.

Abstract: An improved method for providing parallel apply in asynchronous data replication in a database system is disclosed. The improved method and system provides a high speed parallel apply of transactional changes to a target node such that the parallel nature of the application of changes does not compromise the integrity of the data. The method and system detects, tracks, and handles dependencies between transaction messages to be applied to the target node. If a transaction message has a dependency on one or more preceding transaction messages whose applications have not yet completed, that transaction message is held until the application completes. In addition, the method and system requires significantly less overhead than conventional approaches.

Abstract: Database management methods that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

Abstract: Database management systems and program products that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

Abstract: Database management systems, methods, and program products that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

Abstract: A computer readable medium encoded with a computer program for handling transaction messages in asynchronous data replication in a database system is disclosed. The computer program provides a high speed parallel apply of transactional changes to a target node such that the parallel nature of the application of changes does not compromise the integrity of the data. The computer program detects, tracks, and handles dependencies between transaction messages to be applied to the target node. If a transaction message has a dependency on one or more preceding transaction messages whose applications have not yet completed, that transaction message is held until the application completes. In addition, the computer program requires significantly less overhead than conventional approaches.

Abstract: An automatic initial data load to a new table copy concurrently with active replication to existing table copies in an asynchronous replication group includes: initiating a data load of the new table copy; creating spill queue(s) at the new table copy; loading the data from a source table copy to the new table copy, where changes for the active table copies are applied during the loading, but changes to the new table copy are stored in a spill storage area; applying the changes in the spill storage area to the new table copy after the loading of the data is done; and removing the spill storage area after the changes have been applied to the new table copy. Thus, a new table copy is initialized into the replication group without requiring that replication be suspended at the source or any of the existing table copies during the initializing process.

Abstract: A system and method of lightweight asynchronous data replication that avoids the need for any persistent store at the replication source or communication channel, and is independent of the underlying data formats, wherein the method of data replication comprises replicating deltas from a source, embedding replication tracking information in the replicated deltas, wherein the tracking information comprises a timestamp and a sequence number, and applying deltas at a target. The tracking information is used to ensure that each delta is applied exactly once. In the event of a crash in the system, the target analyzes the tracking information to determine which deltas have been applied, and requests retransmission of replicated data from the source starting from the earliest unapplied delta. The source and target are treated as only delta producers and consumers, and as such the invention is applicable to replication between arbitrary data source formats.

Abstract: An improved method and system for preserving data constraints during parallel apply in asynchronous transaction replication in a database system have been disclosed. The method and system preserves secondary unique constraints and referential integrity constraints, while also allowing a high degree of parallelism in the application of asynchronous replication transactions. The method and system also detects and resolves ordering problems introduced by referential integrity cascade deletes, and allows the parallel initial loading of parent and child tables of a referential integrity constraint.