How does Oracle determine if a field is not empty?

In Oracle, you can use the following method to check if a field is empty:

1. Check for NULL using the condition IS NULL.
2. Retrieve all rows from the table where the specified column does not have a value.
3. Check for the condition of IS NOT NULL.
4. Retrieve all records from the table where the specified column is not empty.
5. Use the LENGTH function to determine if the field length is 0.
6. Choose everything from the table where the length of the column is equal to zero.
7. Use the NVL function to determine if a field is empty (for character type fields).
8. Retrieve all rows from the table where the column value is equal to a blank space if the column value is null.
9. Use the COALESCE function to check if a field is empty (for any type of field).
10. Choose all records from the table where the column value is null or empty.

Please choose the appropriate method based on specific needs for evaluation.