Optimizations have been performed t

Optimizations have been performed to ensure that the capture of data is performed efficiently to minimize overhead. One example of these optimizations is in the SQL statement capture. It maintains deltas of the data for SQL statements between snapshots. These let the Oracle Database capture only statements that have significantly impacted the load of the system since the previous snapshot in an efficient manner, rather than having to capture all statements that had performed above a threshold level of work since they first appeared in the system.AWR forms the foundation for all self-management functionality of Oracle Database. It is the source of information that gives the Oracle Database an historical perspective on how it is being used and enables it to make decisions that are accurate and specifically tailored for each environment.