Which two statements are true about the database buffer cache? (Choose two.)
A.
A buffer can be written to by many processes at the same time.
B.
A buffer containing a block that is identical to the block on disk is called free buffer.
C.
A buffer containing a block that is being accessed by a process is called dirty buffer.
D.
A buffer available to be overwritten with a different database block at any time is called a dirty buffer.
E.
A buffer can contain a different version of a block that is available in a different buffer of the same cache.