Null Values - A Whole Lot about Nothing

Storing null values is an important feature of any database. Knowing if data is stored is an essential operation to quickly sort and retrieve data. Providing your application function to pass nothing or no information is key to many workflows where partial or incomplete transactions should be persisted. Let's take a look into how to best leverage null values to optimize or database.

The Silent Players

Why should we care about storing nothing?  Knowing that nothing has been stored for a particular column or field is just as important as understanding the value if something was stored. Thinking about how your database will handle null values should be defined when you first build your data model as well as when you are designing your queries to interact with the data. Additionally, nulls are key to understanding if data can be used for analytics or AI development.

All Upside

There are so many good things from using null values properly. This way databases can efficiently hold data that is empty or partial information to accurately reflect a business process. Nulls can provide the following: 

- Query performance improvements: Null values provide database professionals with the flexibility to index columns efficiently. This allows for faster search operations, as nulls are indexed separately, contributing to improved query performance.

- Better data quality: By utilizing null values, database professionals can avoid the introduction of misleading information. Nulls serve as clear indicators of missing data, preventing misinterpretation, and ensuring that decisions based on the database are made with a comprehensive understanding of the available information.

- Enforce referential integrity: Null values provide a controlled way to delete or update records without violating referential integrity constraints. Instead of forcing cascading updates or deletions, nulls permit a level of flexibility, allowing for the maintenance of relationships without compromising the integrity of the database.

Not all Nulls are Equal

The biggest issue that can arise with null usage is not setting them correctly. Sometimes team can insert 'NA', '   ', 'BLANK', or other strings to indicate an empty value. This will have serious consequences on data quality and database performance. As one of these examples is still a string - so it takes up storage and must be read explicitly by queries when searched. The largest mistake people make with numeric numbers is treating a value of zero as NULL - because these values are not the same.

Null numeric values of zero can skew computations and lead to misinterpretation in reporting. For example, a contract valued as NULL is a contract where the price has yet to be determined or is in negotiation. Whereas a contract with a value of zero means a contract is being completed free of charge or not for a monetary value. If both of these scenarios, were stored with a value of zero - you could see how that would lead to misinterpretation.

In conclusion, leveraging nulls strategically empowers technical teams to build robust and efficient database systems that not only store and retrieve data effectively but also maintain the integrity of relationships between tables. By embracing null values as valuable contributors to the database ecosystem, we can harness them to create more resilient and adaptable systems.

By Ellie Najewicz