Final answer:
The Universal Postal Union (UPU) Code is commonly used as a race code to search all records in a database.
Step-by-step explanation:
The race code that is best used in the inquiry to search all records would depend on the specific system or database being used. However, a commonly used race code is the Universal Postal Union (UPU) Code, which is a two-letter code that represents different races. For example, 'AS' represents Asian, 'BL' represents Black, and 'WH' represents White.
Using a race code can help standardize and organize data in a database, allowing for easier searching and analysis. It is important to note that the use of race codes should be done carefully and with sensitivity, as race is a complex and sensitive topic that requires respectful handling.