单选题Why can setting too low a value for the FAST_START_MTTR_TARGET parameter reduce your overall database performance？（）A Data blocks have to be written more frequently by DBWR. B Redo blocks have to be written more frequently by LGWR. C You need to substa

第1题：

You can control instance recover performance by setting parameters to define targets for（）

• A、The size of the redo buffer in SGA. 
• B、The instance that will perform recovery in Real Application Cluster database. 
• C、The number of blocks to be read during instance recovery, or the time needed to complete instance recovery. 
• D、The number of passes through the redo logs made by the recovery process to identify blocks needing recovery.

第2题：

In the instance of the PROD database， the checkpoint （CKPT） process runs after every minute. A database user updates the rows of the ORDERS table. Because of the configuration， the CKPT process gets initiated before the user commits the transaction. What would happen to the modified blocks when the CKPT process is started？（）

• A、The modified blocks would be written to the data files.
• B、The modified blocks would be written to the temp files.
• C、The modified blocks would be written to the control file.
• D、The modified blocks would be written to the redo log files.
• E、The modified blocks would be written to the archived redo log files.
• F、The modified blocks would be retained in the database buffer cache.

第3题：

第4题：

Why can setting too low a value for the FAST_START_MTTR_TARGET parameter reduce your overall database performance？（）

• A、Data blocks have to be written more frequently by DBWR. 
• B、Redo blocks have to be written more frequently by LGWR. 
• C、You need to substantially increase the size of your database buffer cache to hold the additional checkpoint records. 
• D、You need to substantially increase the size of your redo buffer cache to hold the additional checkpoint records.

第5题：

You have a range-partitioned table in your database. Each partition in the table contains the sales data for a quarter.  The partition related to the current quarter is modified frequently and other partitions undergo fewer data manipulations. The preferences for the table are set to their default values. You collect statistics for the table using the following command in regular intervals： SQL> EXECUTE  DBMS_STATS.GATHER_TABLE_STATS（’SH’，’SALES’，GRANULARITY=>’GLOBAL’）；   You need statistics to be collected more quickly.  What can you do to achieve this？（）

• A、 Set DYNAMIC_SAMPLING to level 4
• B、 Set the STATISTICS_LEVEL parameter to BASIC
• C、 Set the INCREMENTAL value to TRUE for the partition table
• D、 Increase the value of STALE_PERCENT for the partition table

第6题：

You work as a database administrator for Supportcenter.cn. You are using Recovery Manager （RMAN） to perform backups in your databases. Which four backup operations can be performed using RMAN？（）

• A、A backup of the target database when it is mounted
• B、A backup of online redo log files when the database is open
• C、A backup of only used data blocks in the file beingbeingbackup up
• D、A backup of online， read/write data files when the database is open
• E、A backup of only those data blocks that have changed since a previous backup
• F、A backup of online， read/write data files when the database is in the NOMOUNT state.

第7题：

You are working on the 24X7 database with high transaction volume， to ensure faster instance recovery on your database you set the FAST_START_MTTR_TARGET initialization parameter to a very low value. What effect it will have on the database？（）

• A、The database performance would be enhanced.
• B、The redo log files would be get filled more frequently.
• C、The overall database performance would be degraded.
• D、The mean time to recover （MTTR） would be increased.

第8题：

Which  statements are true about checkpointing（）

• A、The checkpoint frequency decreases with the smaller redo log file size.
• B、It ensures that all committed data is written to the data files during normal shutdown.
• C、The frequent full checkpoint in a database can cause the overall degradation of the database performance.
• D、It prompts the Checkpoint （CKPT） process to write data to the data files and redo information to the onlineredo log files

第9题：

Which two statements are true regarding the database in ARCHIVELOG mode？（）

• A、You have to shut down the database to perform the backups.
• B、Archiving information is written to the data files and redo log files.
• C、You can perform complete database backups without closing the database.
• D、Online redo log files have to be multiplexed before putting the database in ARCHIVELOG mode.
• E、All the previous database backups become invalid after you configure the database to ARCHIVELOG mode.

第10题：

Which two statements are true about checkpointing（）

• A、The checkpoint frequency decreases with the smaller redo log file size.
• B、It ensures that all committed data is written to the data files during normal shutdown.
• C、The frequent full checkpoint in a database can cause the overall degradation of the database performance.
• D、It prompts the Checkpoint （CKPT） process to write data to the data files and redo information to the online redo log files.