CUUG内部OCP题库解析-053-文档6

CUUG内部OCP题库解析-053-文档6题库新特点：oracle 11g版本的ocp 053认证考试是所有这几科里数量最多的考试了，cuug整理了近期的053考题，并进行了讲解。下面的题是（053考试-第6个文档）里的一些考题。其他题找相关文档，或者在群里讨论101-5267-481Administrator CUUG内部OCP题库解析-052-文档2 7/17/1951.To control the execution of a server process when it is receiving badpackets from a potentially malicious client, you set theSEC_PROTOCOL_ERROR_FURTHER_ACTION initialization parameter asfollows:SQL> ALTER SYSTEM SET SEC_PROTOCOL_ERROR_FURTHER_ACTION= Drop,10;What is the significance of this setting?A. It terminates the client connection after 10 bad packets and the client cannotreconnect to the same instance.B. It terminates the client connection after 10 bad packets but the client can stillreconnect, and attempt the same operation again.C. It terminates the client connection 10 seconds after receiving a bad packetand the client cannot reconnect to the same instance.D. It terminates the client connection after receiving a bad packet and the clientcan reconnect to the same instance after 10 minutes.Answer: BB,在发现有10个坏包后终止客户端连接，但客户端仍然可以重新连接，并再 次尝试同样的操作。SEC_PROTOCOL_ERROR_FURTHER_ACTION specifies the further execution of aserver process when receiving bad packets from a possibly malicious client.Values:CONTINUEThe server process continues execution. The database server may be subject to aDenial of Service (DoS) if bad packets continue to be sent by a malicious client.(DELAY,integer)The client experiences a delay of integer seconds before the server process accepts thenext request from the same client connection. Malicious clients are prevented fromexcessive consumption of server resources while legitimate clients experience adegradation in performance but can continue to function.(DROP,integer)The server forcefully terminates the client connection after integer cumulative badpackets. The server protects itself at the expense of the client (for example, a clienttransaction may be lost). The client may reconnect and attempt the same operation.52.You have the following requirements in relation to the detection of blockcorruption for your database instance:Check for logical self-consistency of data blocks when modified in memory.Checksums are calculated before and after the block change.Checks are performed for the lost writes to the physical standby database.Which method would help you perform the above checks automatically?A. Set the DB_SECUREFILE parameter to PERMITTED.B. Set the DB_ULTRA_SAFE parameter to DATA_ONLY.C. Set the DB_BLOCK_CHECKSUM parameter to TYPICAL.D. Set the DB_LOST_WRITE_PROTECT parameter to TYPICAL.Answer: BDB_ULTRA_SAFE sets the default values for other parameters that control protection levels.简单点，DB_ULTRA_SAFE参数整合了DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM, 和 DB_LOST_WRITE_PROTECT三个 参数。DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM这两个参数在上一篇博文中说明过 了。参数DB_BLOCK_CHECKSUM和DB_BLOCK_CHECKING的说明DB_LOST_WRITE_PROTECT参数只有在dg的时候用到，dg需要介质恢复时，系统会完成丢失的写保护。DB_ULTRA_SAFE参数DB_ULTRA_SAFE = OFF | DATA_ONLY | DATA_AND_INDEX ,默认值为OFF。当DB_ULTRA_SAFE 设置为:（1）OFF：When any of DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM,or DB_LOST_WRITE_PROTECT are explicitly set, no changes are made.-不改变这三个参数的值。（2）DATA_ONLY： 三个参数会按照如下方式进行修改：DB_BLOCK_CHECKING will be set to MEDIUM.DB_LOST_WRITE_PROTECT will be set to TYPICAL.DB_BLOCK_CHECKSUM will be set to FULL.（3）DATA_AND_INDEX： 三个参数会按照如下方式进行修改： DB_BLOCK_CHECKING will be set to FULL.DB_LOST_WRITE_PROTECT will be set to TYPICAL.DB_BLOCK_CHECKSUM will be set to FULL.53.You want to use RMAN to create compressed backups.Which statement is true about the compression algorithms that RMANcan use?A. The BZIP2 compression algorithm consumes more CPU resources thanthe ZLIB compression algorithm.B. The ZLIB compression algorithm consumes more CPU resources thanthe BZIP2 compression algorithm.C. The ZLIB compression algorithm provides maximum compression andproduces smaller backups than the BZIP2 compression algorithm.D. Only the BZIP2 compression algorithm can be used to makecompressed backups to disk.Answer: A建议大家可以测试两者的速度和压缩率54.Evaluate the following function code:CREATE FUNCTION get_dept_avg(dept_id NUMBER) RETURN NUMBER RESULT_CACHE RELIES_ON(EMPLOYEES) IS avgsal NUMBER(6); BEGINSELECT AVG(SALARY)INTO avgsal FROM EMPLOYEESWHERE DEPARTMENT_ID = dept_id; RETURN avgsal; END get_dept_avg;Which statement is true regarding the above function?A. The cached result becomes invalid when any structural change is done to the EMPLOYEES table.B. If the function execution results in an unhandled exception, the exception result is also stored in the cache.C. Each time the function is invoked in a different session, the current result in theresult cache gets overwritten.D. If the function is invoked with a different parameter value, the existing result inthe result cache gets overwritten by the latest value.Answer: AEnabling Result-Caching for a FunctionTo make a function result-cached,incl