Abstract: Database change test system that includes an SQL performance analyzer (SPA) to efficiently test execute workload set of queries on a production or test database management system (DBMS) and report to a user the impact of database changes, is provided. Techniques are described that limit the resource consumption of test execution of workload set of queries, especially to enable such test execution on a production DBMS. A method and apparatus for storing in persistent storage query test profile that specifies query test restrictions and execution plan parameters, which indicate how to generate execution plan operators for query execution plans; storing a workload set of queries in persistent storage; establishing a session with a database management systems; retrieving the query test profile; configuring the session according to the test profile; receiving user input requesting to execute the workload set; and executing the queries according to the query test profile, is also provided.

Abstract: Systems, methods, and other embodiments associated with continuous capture of replayable workload for a database are described. In one embodiment, a method includes capturing workload units being executed on a production database and storing the captured workload units in a circular workload buffer. The circular workload buffer is configured to write newest captured workload units over oldest workload units in the workload buffer when the workload buffer becomes full. The method includes, in response to detecting an event, exporting contents of the workload buffer to offline memory. The exporting includes at least one I/O operation. In one embodiment, an advisor feature guides set up of the continuous capture feature by providing historical workload data and making recommendations regarding an amount of memory that should be allocated to the workload buffer.

Abstract: High-risk database statements are identified. A DBMS performs a series of experiments by generating sets of statistics describing data over which particular database statements run. The DBMS submits each of these sets of statistics to a query optimizer, which returns information for an execution plan that the optimizer would use to implement the statements given the submitted set of data statistics. If the DBMS determines that the optimizer changes the established execution plan for the database statements for any of the submitted sets of statistics, the DBMS performs one or more actions to mitigate the risk of changing execution plans, such as automatically tuning the database statements or the entire workload, and/or sending information about the database statements to a database administrator. Techniques are also described for calculating diagnostic values based on the results of such experiments, which quantify the sensitivity of the execution plans to changes in data statistics.

Abstract: Systems, methods, and other embodiments associated with continuous capture of replayable workload for a database are described. In one embodiment, a method includes capturing workload units being executed on a production database and storing the captured workload units in a circular workload buffer. The circular workload buffer is configured to write newest captured workload units over oldest workload units in the workload buffer when the workload buffer becomes full. The method includes, in response to detecting an event, exporting contents of the workload buffer to offline memory. The exporting includes at least one I/O operation. In one embodiment, an advisor feature guides set up of the continuous capture feature by providing historical workload data and making recommendations regarding an amount of memory that should be allocated to the workload buffer.

Abstract: Database change test system that includes an SQL performance analyzer (SPA) to efficiently test execute workload set of queries on a production or test database management system (DBMS) and report to a user the impact of database changes, is provided. Techniques are described that limit the resource consumption of test execution of workload set of queries, especially to enable such test execution on a production DBMS. A method and apparatus for storing in persistent storage query test profile that specifies query test restrictions and execution plan parameters, which indicate how to generate execution plan operators for query execution plans; storing a workload set of queries in persistent storage; establishing a session with a database management systems; retrieving the query test profile; configuring the session according to the test profile; receiving user input requesting to execute the workload set; and executing the queries according to the query test profile, is also provided.

Abstract: High-risk database statements are identified. A DBMS performs a series of experiments by generating sets of statistics describing data over which particular database statements run. The DBMS submits each of these sets of statistics to a query optimizer, which returns information for an execution plan that the optimizer would use to implement the statements given the submitted set of data statistics. If the DBMS determines that the optimizer changes the established execution plan for the database statements for any of the submitted sets of statistics, the DBMS performs one or more actions to mitigate the risk of changing execution plans, such as automatically tuning the database statements or the entire workload, and/or sending information about the database statements to a database administrator. Techniques are also described for calculating diagnostic values based on the results of such experiments, which quantify the sensitivity of the execution plans to changes in data statistics.