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.
C,E
I also think that, the correct answer should be C, E
I think that the correct is B and F.
B because “Second to the maximum precision” – Only TIMESTAMP contains fractional seconds!!!
VARCHAR is variable-length.
CHAR is fixed length.
If your content is a fixed size, you’ll get better performance with CHAR.