Abstract: A latent auxiliary database structure constructed for executing a query is automatically saved for reuse in subsequent query execution instances. The latent auxiliary database structure is not maintained concurrently with changes to records in the database tables. If a query execution strategy is subsequently invoked which uses the latent auxiliary database structure, a determination is made dynamically whether to update the previously saved latent structure from database changes recorded in one or more change logs, or to rebuild the latent structure from scratch. Where the cost of updating from the change log is deemed less than the cost of a rebuild from scratch, the previously saved latent structure is updated from the log.

Abstract: Nodes in a query execution data structure have monitor and dump methods defined. The monitor method enables the collection of information from the node. The dump method outputs the monitored information from each node. A monitor and debug mechanism of the preferred embodiments includes a graphical user interface that allows a user to graphically examine a query execution tree, to enable monitoring of the nodes on a node-by-node basis, and to view information dumped from the query execution data structure as the query is executed or after the query is executed. The result is a powerful tool that allows efficiently monitoring and debugging a query implemented in an object oriented query execution data structure.