OCP-1Z0-052-V8 02-12题

分享一下我老师大神的人工智能教程！零基础，通俗易懂！http://blog.youkuaiyun.com/jiangjunshow

也欢迎大家转载本篇文章。分享知识，造福人民，实现我们中华民族伟大复兴！

               

12. Which is the correct description of a pinned buffer in the database buffer cache?

A.The buffer is currently being accessed.

B.The buffer is empty and has not been used.

C.The contents of the buffer have changed and must be flushed to the disk by the DBWn process.

D.The buffer is a candidate for immediate aging out and its contents are synchronized with the block

contents on the disk.

Answer: A

答案解析：

Every buffer has an access mode: pinnedor free(unpinned). A buffer is "pinned" in the cache so that it does not age out of memory while a user session accesses it. Multiple sessions cannot modify a pinned buffer at the same time.

官方参考：http://docs.oracle.com/cd/E11882_01/server.112/e40540/memory.htm#CNCPT1222

           

给我老师的人工智能教程打call！http://blog.youkuaiyun.com/jiangjunshow