Oracle Automated Shared Memory Management is a new feature introduced in Oracle 10g Databases. In 10g you specify SGA_TARGET instead of the older methods of setting the initialization parameters such as SHARED_POOL_SIZE, DB_CACHE_SIZE. This allows for Automatic Database Performance tuning in Oracle Databases

Oracle 10g provides a multitude of new features that allow better performance monitoring and management. The content below give you a high level overview of the Performance Management Features and we will cover each of them in detail in the coming weeks

Introduction of Oracle Table Compression since Oracle 9i has allowed the compression of Tables, Partitions and Materialized views. This feature targeted at OLAP and Warehousing applications allows for drastic reduction in disk space and memory requirements when used appropriately.

The Oracle 10g Database introduces a new component called Active Session History (ASH) which can be used to identify blocker and waiter session identities and their associated transaction identifiers and SQL for a specified duration of the report. This data for the sample session activity in the instance is provided by V$ACTIVE_SESSION_HISTORY view. A circular buffer in the SGA contains the sampled data of the active sessions. All sessions that are connected to the db and are waiting for an non-idle class event is considered an active session. This includes any session that was running on the CPU at the time of sampling. Sampling is done every second and contains a lot of useful information for Oracle Performance Tuning