How Can I Store Only Time Values (Without Dates) in Oracle Databases?

Storing Time Only Without Date in Oracle Databases

When dealing with large datasets, it is beneficial to optimize data storage to minimize space and enhance processing efficiency. In Oracle databases, storing time-related data often involves using the DATE data type, which includes both date and time components. However, there are scenarios where you may need to store only time, without the date.

Storing Time Using INTERVAL DAY TO SECOND

Oracle provides the INTERVAL DAY TO SECOND data type, which allows you to store time intervals without the date component. This data type can be particularly useful when you need to store time information independently, such as in your example.

Advantages of Using INTERVAL DAY TO SECOND

Using INTERVAL DAY TO SECOND has several advantages:

• Tailored for Time Storage: It is specifically designed for storing time intervals, making it a suitable choice for your use case.

Creating an Interval Day to Second Column

To create a column of type INTERVAL DAY TO SECOND, you can use the following syntax:

CREATE TABLE t1 (time_of_day INTERVAL DAY(0) TO SECOND(0));

Inserting Time Values

To insert time values into the INTERVAL DAY TO SECOND column, you can use the TO_DSINTERVAL function:

INSERT INTO t1 VALUES (TO_DSINTERVAL('0 23:59:59'));

Example Usage

To demonstrate the usage of the INTERVAL DAY TO SECOND data type, you can run the following query:

SELECT DATE '2009-05-13' + time_of_day
FROM t1;

This query will add the time stored in the time_of_day column to the date '2009-05-13' to give you the combined date and time value.

Space Considerations

While INTERVAL DAY TO SECOND is suitable for storing time-only data, it is important to note that it does not necessarily save disk space compared to using the DATE data type. The actual space usage will depend on the specific implementation and data distribution.

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