How does Oracle retrieve the length of a field value?

To obtain the length of a field value, you can use the LENGTH function in Oracle. This function takes a string as a parameter and returns the length of that string. For example:

SELECT LENGTH(column_name) AS column_length
FROM table_name;

In this example, the length of the values in column_name from table_name will be returned. You can replace the table and column names as needed.