Oracle OCP IZ0-053 Q157(DB_BLOCK_CHECKING)
performed?
A. The Oracle database will perform block checking for the index blocks only
B. The Oracle database will not perform block checking for any of the data blocks
C. The Oracle database will perform block checking for the default permanent tablespace only
D. The Oracle database will perform block checking for the data blocks in all user tablespaces
E. The Oracle database will perform block checking for the data blocks in the SYSTEM tablespace only
Answer: E
http://docs.oracle.com/cd/E11882_01/server.112/e40402/initparams048.htm#REFRN10029
DB_BLOCK_CHECKING specifies whether or not Oracle performs block checking for database blocks.
Values:
-
OFF or FALSE
No block checking is performed for blocks in user tablespaces. However, semantic block checking for SYSTEM tablespace blocks is always turned on.
-
LOW
Basic block header checks are performed after block contents change in memory (for example, after UPDATE or INSERT statements, on-disk reads, or inter-instance block transfers in Oracle RAC).
-
MEDIUM
All LOW checks and full semantic checks are performed for all objects except indexes (whose contents can be reconstructed by a drop+rebuild on encountering a corruption).
-
FULL or TRUE
All LOW and MEDIUM checks and full semantic checks are performed for all objects.
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/8520577/viewspace-2055040/ ，如需转载，请注明出处，否则将追究法律责任。
