Abstract: A method, system, and computer program product for transmitting a redo stream from a database to one or more distributed database systems, upon which applications that process the redo stream are implemented, and which maintains the data dictionaries by replicating the multiple versions of the schema objects to data dictionaries in the distributed database systems. A method of maintaining a multi-version data dictionary includes generating a logical redo stream, inserting procedure calls to be used to populate the multi-version data dictionary into the generated logical redo stream, transmitting the logical redo stream to the multi-version data dictionary, and executing the procedure calls at the multi-version data dictionary to populate the multi-version data dictionary.

Abstract: Schema evolution involves defining flavored object groups. Specifically, related collections of replicated tables and other database objects, which are defined as belonging to an object group, are given different “flavors.” A flavor describes different subsets of the objects and even different subsets of the columns in the master tables. In one embodiment, when one site in a distributed database system propagates changes to a replicated database object, the current flavor for the site is also transmitted, so that the destination site can make the necessary adjustments in the uploaded changes by dropping the values for obsolete columns and using default values for new columns.

Abstract: A method for applying changes to a standby system is described in which multiple apply tasks or “slaves” are scheduled to changes from redo logs, especially those changes in large transactions, in parallel and as soon as they are encountered in the logs. To foster data convergence, a partial ordering may be imposed on the transactions so that those transactions that actually depend on others are forced to wait on the transactions they are dependent upon commit. To foster read consistency, synchronization points may be periodically established, at which points a read consistent state of the standby database system can be obtained-all without adversely impact the throughput of the system.

Abstract: A method, system, and computer program product for transmitting a redo stream from a database to one or more distributed database systems, upon which applications that process the redo stream are implemented, and which maintains the data dictionaries by replicating the multiple versions of the schema objects to data dictionaries in the distributed database systems. A method of maintaining a multi-version data dictionary comprises the steps of generating a logical redo stream, inserting procedure calls to be used to populate the multi-version data dictionary into the generated logical redo stream, transmitting the logical redo stream to the multi-version data dictionary, and executing the procedure calls at the multi-version data dictionary to populate the multi-version data dictionary.

Abstract: Replication for front office automation involves the use of snapshots that are instantiated on laptops, in which refreshing the snapshots is driven from a master site with a high-performance protocol. All of the necessary snapshot metadata for performing the snapshot refreshes is stored at the master site, so that the laptop only needs to send a single refresh request. In response to the refresh request, the master site reconciles the differences between the master tables and the laptop's snapshots and transmits the differences to the laptop, reducing the necessary network traffic for updating a snapshot to a single round trip.

Abstract: Replication for front office automation involves the use of snapshots that are instantiated on laptops, in which refreshing the snapshots is driven from a master site with a high-performance protocol. All of the necessary snapshot metadata for performing the snapshot refreshes is stored at the master site, so that the laptop only needs to send a single refresh request. In response to the refresh request, the master site reconciles the differences between the master tables and the laptop's snapshots and transmits the differences to the laptop, reducing the necessary network traffic for updating a snapshot to a single round trip.

Abstract: Schema evolution involves defining flavored object groups. Specifically, related collections of replicated tables and other database objects, which are defined as belonging to an object group, are given different “flavors.” A flavor describes different subsets of the objects and even different subsets of the columns in the master tables. In one embodiment, when one site in a distributed database system propagates changes to a replicated database object, the current flavor for the site is also transmitted, so that the destination site can make the necessary adjustments in the uploaded changes by dropping the values for obsolete columns and using default values for new columns.