作业帮oracle试题怎么做,解释可不可以详细一点.
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oracle试题怎么做,解释可不可以详细一点.
In your Oracle 10g database ,you have scheduled a job to update the optimizer statistics at 05:00 pm
every Friday.The job has successfully completed.Which three pieces of information would you check to
confirm that the statistics have been collected?(Choose three.)
A.average row size
B.last analyzed date
C.size of table in bytes
D.size of table in database blocks
E.number of free blocks in the free list
F.number of extents present in the table
In your Oracle 10g database ,you have scheduled a job to update the optimizer statistics at 05:00 pm
every Friday.The job has successfully completed.Which three pieces of information would you check to
confirm that the statistics have been collected?(Choose three.)
A.average row size
B.last analyzed date
C.size of table in bytes
D.size of table in database blocks
E.number of free blocks in the free list
F.number of extents present in the table
B、C、D,数据库的统计信息是为让数据库产生更优的执行计划,更新统计信息包含了B、C、D三个选择的内容,特别是last analyzed date最容易反映出来信息有没有更新.