1z0-071 Oracle Database 12c SQL 第46题 字符串类型和时间类型

Q46.  You are designing the structure of a table in which two columns have the specifications:

COMPONENT_ID – must be able to contain a maximum of 12 alphanumeric characters and uniquely identify the row

EXECUTION_DATETIME – contains Century, Year, Month, Day, Hour, Minute, Second to the maximum precision and is used for calculations and comparisons between components.

Which two options define the data types that satisfy these requirements most efficiently?

A. The EXECUTION_DATETIME must be of INTERVAL DAY TO SECOND data type.

B. The EXECUTION_DATETIME must be of TIMESTAMP data type.

C. The EXECUTION_DATETIME must be of DATE data type.

D. The COMPONENT_ID must be of ROWID data type.

E. The COMPONENT_ID must be of VARCHAR2 data type.

F. The COMPONENT_ID column must be of CHAR data type.

Correct Answer: CE

Component_id isn’t necessarily always going to 12 bytes, if it is shorter you are not being “efficient”.