单项选择题
A.The ALTER TABLE command modifies the column successfully.
B.The DDL operation gets higher priority and transaction for user a is rolled back.
C.The ALTER TABLE command waits indefinitely until user a ends the transaction.
D.The ALTER TABLE command fails after waiting for 60 seconds due to the resource being busy.
单项选择题 Automatic Shared Memory Management is disabled for your database instance. You realize that thereare cases of SQL statements performing poorly because of repeated parsing activity， resulting indegradation of performance. What would be your next step to improve performance？ （）
单项选择题 View Exhibit1 and Exhibit2 to examine the current memory allocation and parameter settings，respectively. Why are advisors not available for the shared pool and the buffer cache()
单项选择题 View the Exhibit to examine the output produced by the following query at three different times sincethe database instance started and has experienced workloads of different capacities： SQL> SELECT substr（component， 0， 10） COMP， current_size CS，user_specified_size USFROM v$memory_dynamic_componentsWHERE current_size!=0； What do you infer from this（）
