The Oracle PL/SQL TIMESTAMP WITH LOCAL TIME ZONE data type is used to store date and time information along with the corresponding time zone offset. This data type is particularly useful when dealing with applications that operate in multiple time zones.
Here are some key points about the TIMESTAMP WITH LOCAL TIME ZONE data type:
Precision: This data type allows for storing fractional seconds, providing a high level of precision in time measurements.
Time Zone Information: Unlike the TIMESTAMP data type, which doesn’t store time zone information, TIMESTAMP WITH LOCAL TIME ZONE includes information about the time zone where the timestamp was recorded. This is crucial for applications that need to handle time zone conversions and daylight saving time changes.
Local Time Zone: The “LOCAL” in the data type name refers to the fact that it automatically adjusts the timestamp to the local time zone of the database session. When you insert a timestamp into a column of this data type, Oracle converts it to the session time zone for storage.
Automatic Time Zone Adjustments: When retrieving data from a TIMESTAMP WITH LOCAL TIME ZONE column, Oracle automatically adjusts the timestamp to the time zone of the querying session. This ensures consistency and accuracy when working with timestamps across different time zones.
CREATE TABLE event_schedule ( event_name VARCHAR2(50), event_timestamp TIMESTAMP WITH LOCAL TIME ZONE ); INSERT INTO event_schedule VALUES ('Meeting', TIMESTAMP '2023-11-17 09:00:00 America/New_York'); SELECT * FROM event_schedule;
In this example, the timestamp is associated with the ‘America/New_York’ time zone, and Oracle automatically adjusts it to the local time zone of the session when queried.
Using TIMESTAMP WITH LOCAL TIME ZONE can simplify the handling of time zone information in your PL/SQL code, as it abstracts much of the complexity associated with time zone conversions. However, it’s crucial to be aware of the session time zone settings to ensure accurate and meaningful results.