摘要： 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... 阅读全文

摘要： Round-trip time when running "select 1 from dual" (includes network time but not connect time) on this database. SolutionIf this is high, contact your network administrator to understand network lat... 阅读全文

摘要： 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... 阅读全文

摘要： 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. SolutionReduce the degree of ... 阅读全文

摘要： 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. SolutionReduce the degree of parallelism in the q... 阅读全文

摘要： 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... 阅读全文

摘要： A session waits on this event when it has requested a mutex for a cursor object in exclusive mode but must wait because it is busy. The mutex is busy because either the mutex is being held in exclusiv... 阅读全文

摘要： A session waits on this event when it wants to update a shared mutex pin and another session is currently in the process of updating a shared mutex pin for the same cursor object. This wait event shou... 阅读全文

摘要： A session waits on this event when requesting a mutex for sharable operations related to pins (such as executing a cursor), but the mutex cannot be granted because it is being held exclusively by anot... 阅读全文

摘要： Wait occurs when a session attempts to access a block in memory, is denied and must wait until the buffer becomes available. This event happens because a buffer is either being read into the buffer ca... 阅读全文