[多选]

You work as a database administrator for Certkiller .com. Users in the Certkiller PROD database complain about the slow response when accessing the database. In the Active Session Waiting： Configuration page you find that the majority of the wait time is for the redo log buffer.Further investigation using the Run Queue graph and operating system tools reveals that the redo log files are on the same disks， and that the disk I/O for the redo log files is the reason for the performance degradation. 
Which two actions would you take to gain performance？（）

Examine the following command:ALTER SYSTEM SET enable_ddl_logging=FALSE;Which statement is true?（） None of the data definition language (DDL) statements are logged in the trace file.。 Only DDL commands that resulted in errors are logged in the alert log file.。 A new log.xml file that contains the DDL statements is created, and the DDL command details are removed from the alert log file.。 Only DDL commands that resulted in the creation of new database files are logged.。 有氧耐力训练 MustInherit修饰符用于"抽象类"。 竞争性拮抗剂具有下列特点（） 使激动药量效曲线平行右移。 使激动剂的最大效应降低。 竞争性拮抗作用是可逆的。 拮抗参数pA2越大，拮抗作用越强。 与受体有高度亲和力，无内在活性。 Your database operates in ARCHIVELOG mode. User-managed consistent backups are performed every  Sunday night. On Tuesday， client A drops a table at 8：00 a.m. as follows：  SQL> DROP TABLE cust_ord PURGE；  Table dropped.  Client B executes a query at 9：00 a.m. on the same table as follows：  SQL> SELECT * FROM cust_ord；  SELECT * FROM cust_ord  *ERROR at line 1：ORA-00942： table or view does not exist  Client B needs the dropped table and reports the problem to you.With reference to this scenario， which action should you take？（）  retrieve the table by using the flashback feature。  restore all the data files from last Sunday’s backup and then perform a time-based recovery。  restore all the data files from last Sunday’s backup and then perform a log sequence recovery。  restore all the data files from last Sunday’s backup and then perform a cancel-based recovery。  restore from last Sunday’s backup only data files that belong to the tablespace in which the table was stored and then perform a complete recovery。

You work as a database administrator for Certkiller .com. Users in the Certkiller PROD database complain about the slow response when accessing the database. In the Active Session Waiting： Configuration page you find that the majority of the wait time is for the redo log buffer.Further investigation using the Run Queue graph and operating system tools reveals that the redo log files are on the same disks， and that the disk I/O for the redo log files is the reason for the performance degradation. 
Which two actions would you take to gain performance？（）