When RUNTIMESTATISTICS is turned on for a connection, Derby maintains information about the execution plan for each statement executed within the connection (except for COMMIT) until the attribute is turned off.
This can help in benchmarking queries.
This is a description of result set nodes, whether an index was used, what the join order was, how many rows qualified at each node, and how much time was spent in each node. This information can help you determine whether you need to add indexes or rewrite queries.
The exact details presented, as well as the format of presentation, can change.