Abstract: A method for maintaining a memory replica of a primary computer system to be used by an alternate computer system is provided. Provided are detecting changes performed on a memory device of the primary computer system by software executed on the primary computer system. Also provided is monitoring at least one memory controller of the primary computer system; triggering, based on the monitoring, a snapshot creation procedure, the snapshot creation procedure comprising creating a memory snapshot that comprises the detected changes.

Abstract: A computer-implemented method for seamlessly performing a maintenance operation on a stateful system includes mapping a network address of the stateful system to a primary server that uses a primary database to respond to incoming data requests. In response to receiving a maintenance request, the primary database is replicated to a secondary database of a secondary server. The secondary server is updated according to the maintenance request. The method further includes caching, in a replay buffer of the primary server, incoming data requests during the replicating. After the replicating, the data requests from the replay buffer are executed by the secondary server. Write operations to the primary server are disabled during the replicating, and the network address of the stateful system is mapped to the secondary server. Subsequently, the primary server is updated and reinstated by mapping the network address, and enabling the write operations.

Abstract: Methods and systems for generating database statistics. Table statistics in a metadata catalog of a source database system are observed, statistics generation costs utilizing a target database system are estimated, and source statistics generation costs utilizing a source database system are estimated. The statistics generation costs are compared and statistics generation queries by the target database system are triggered in response to the statistics generation costs utilizing the target database system having a predefined relationship with the source statistics generation costs utilizing the source database system. The statistics generation queries are performed by the target database system in response to the triggering by the source database system. The generated statistics are sent from the target database system to the source database system, the table statistics in a metadata catalog are updated based on the generated statistics, and the updated table statistics are used to optimize a query plan.

Abstract: A computer-implemented method for seamlessly performing a maintenance operation on a stateful system includes mapping a network address of the stateful system to a primary server that uses a primary database to respond to incoming data requests. In response to receiving a maintenance request, the primary database is replicated to a secondary database of a secondary server. The secondary server is updated according to the maintenance request. The method further includes caching, in a replay buffer of the primary server, incoming data requests during the replicating. After the replicating, the data requests from the replay buffer are executed by the secondary server. Write operations to the primary server are disabled during the replicating, and the network address of the stateful system is mapped to the secondary server. Subsequently, the primary server is updated and reinstated by mapping the network address, and enabling the write operations.

Abstract: Methods and systems for generating database statistics. Table statistics in a metadata catalog of a source database system are observed, statistics generation costs utilizing a target database system are estimated, and source statistics generation costs utilizing a source database system are estimated. The statistics generation costs are compared and statistics generation queries by the target database system are triggered in response to the statistics generation costs utilizing the target database system having a predefined relationship with the source statistics generation costs utilizing the source database system. The statistics generation queries are performed by the target database system in response to the triggering by the source database system. The generated statistics are sent from the target database system to the source database system, the table statistics in a metadata catalog are updated based on the generated statistics, and the updated table statistics are used to optimize a query plan.

Abstract: A method for maintaining a memory replica of a primary computer system to be used by an alternate computer system is provided. Provided are detecting changes performed on a memory device of the primary computer system by software executed on the primary computer system. Also provided is monitoring at least one memory controller of the primary computer system; triggering, based on the monitoring, a snapshot creation procedure, the snapshot creation procedure comprising creating a memory snapshot that comprises the detected changes.

Abstract: A method for a continuous mutual extended processor self-test is provided. The method is implemented by a system including a plurality of cores. The system sets an operating condition for the continuous mutual extended processor self-test. An assist processor of the plurality of cores executes a test program that implements the continuous mutual extended processor self-test on a core under test of the plurality of cores. The system determines a pattern and a response during the test program execution and repeats the test program until the test program has finished or failed.

Abstract: A method for a continuous mutual extended processor self-test is provided. The method is implemented by a system including a plurality of cores. The system sets an operating condition for the continuous mutual extended processor self-test. An assist processor of the plurality of cores executes a test program that implements the continuous mutual extended processor self-test on a core under test of the plurality of cores. The system determines a pattern and a response during the test program execution and repeats the test program until the test program has finished or failed.