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One of the main new features associated with Exadata systems is that I/O can be offloaded to storage servers rather than be done on the database server. Each of the storage servers may get a piece of ...

The term "seconds in wait" means the number of seconds that a SQL Statement, Database User, etc. was waiting on an event. It is possible that the total number of "seconds in wait" exceeds the total am...

Round-trip time when running "select 1 from dual" (includes network time but not connect time) on this database. Solution If this is high, contact your network administrator to un...

Shareable SQL uses bind variables rather than literal values. If an application makes use of literal (unshared) SQL then this can severely limit scalability and throughput. The cost of parsing a new S...

Contention caused by communication between parallel query processes. Solutions Decrease the degree of parallelism for the queries Tune the parallel_execution_message_size paramete...

Occurs when a parallel slave is waiting for data from another slave. Investigate why the other slaves are not sending data fast enough. This is normally considered an idle event, but can cause excessi...

Occurs when a parallel slave is waiting to be told what to do. This is normally considered an idle event, but can cause excessive CPU in some cases. Solution Reduce the degree of ...

Occurs when the query coordinator is waiting for a response from a parallel slave. This is normally considered an idle event, but can cause excessive CPU in some cases. Solution R...

The library cache (a component of the shared pool) stores the executable (parsed or compiled) form of recently referenced SQL and PL/SQL code. Oracle tries to reuse this code. If the code has been exe...

To change an init.ora parameter, follow these steps. Open the file called init<database_name>.ora. For example, if the database is called oraprod, then the file would be called initoraprod.ora. ...