463.Which of the following datatypes store time-zone information in the database?
A. TIMESTAMP
B. DATE
C. TIMESTAMP WITH TIME ZONE
D. TIMESTAMP WITH LOCAL TIME ZONE
E. DATETIME
Answer: C
答案解析:
参考:http://docs.oracle.com/cd/E11882_01/server.112/e41084/sql_elements001.htm#SQLRF00205
TIMESTAMP
WITH
TIME
ZONE
is a variant of TIMESTAMP
that includes a time zone region name or a time zone offset in its value. The time zone offset is the difference (in hours and minutes) between local time and UTC (Coordinated Universal Time—formerly Greenwich Mean Time). This data type is useful for preserving local time zone information.
Specify the TIMESTAMP
WITH
TIME
ZONE
data type as follows:
where fractional_seconds_precision
optionally specifies the number of digits Oracle stores in the fractional part of the SECOND
datetime field. When you create a column of this data type, the value can be a number in the range 0 to 9. The default is 6.
Oracle time zone data is derived from the public domain information available at http://www.iana.org/time-zones/
. Oracle time zone data may not reflect the most recent data available at this site.
TIMESTAMP
WITH
LOCAL
TIME
ZONE
is another variant of TIMESTAMP
that is sensitive to time zone information. It differs from TIMESTAMP
WITH
TIME
ZONE
in that data stored in the database is normalized to the database time zone, and the time zone information is not stored as part of the column data. When a user retrieves the data, Oracle returns it in the user's local session time zone. This data type is useful for date information that is always to be displayed in the time zone of the client system in a two-tier application.
Specify the TIMESTAMP
WITH
LOCAL
TIME
ZONE
data type as follows:
where fractional_seconds_precision
optionally specifies the number of digits Oracle stores in the fractional part of the SECOND
datetime field. When you create a column of this data type, the value can be a number in the range 0 to 9. The default is 6.
Oracle time zone data is derived from the public domain information available at http://www.iana.org/time-zones/
. Oracle time zone data may not reflect the most recent data available at this site.