OCP 1Z0 052 188

188.  You  receive  complaints  from  users  regarding  the  high  waiting  time  for  their  transactions.  On 
investigation,  you  find  that  some  users  are  not  committing  their  transactions  though  they  are  not 
performing any activity for a long time. As a result, SQL statements need to wait for row-level locks.  
Which two actions could you take to prevent this locking problem in the future? (Choose two.) 
A.Decrease the IDLE_TIME resource limit in the profile assigned to the blocking users. 
B.Use Database Resource Manager to automatically log out sessions that block others and are idle. 
C.Set the limit in the profile of blocking users to control the number of blocks to be accessed in a session. 
D.Decrease the maximum number of interested transaction list (ITL) slots for the segments on which the 
blocking user performs the transaction. 
Answer: AB   

A  直接通过profile参数让非活动用户 超时退出

http://docs.oracle.com/cd/E11882_01/server.112/e41084/statements_6010.htm#SQLRF54286
IDLE_TIME Specify the permitted periods of continuous inactive time during a session, expressed in minutes. Long-running queries and other operations are not subject to this limit.

SQL> SELECT resource_name  2    FROM dba_profiles  3   WHERE profile = 'DEFAULT'  4     AND resource_name = 'IDLE_TIME';RESOURCE_NAME--------------------------------IDLE_TIME1 row selected

http://docs.oracle.com/cd/E11882_01/server.112/e25494/dbrm.htm#ADMIN11841

About Oracle Database Resource Manager

Oracle Database Resource Manager (the Resource Manager) enables you to manage multiple workloads within a database that are contending for system and database resources.

C D  限制资源只会让等待更长