How Data Types and Query Tuning Can Improve Application Performance
One of the easier ways to improve the performance of your SQL Server and Azure SQL database queries is to ensure you choose the right data types for your data, and the data types in your application’s code match the ones in your stored procedures and queries. Choosing the right data type conserves space, because doing something like choosing a variable character type for data of fixed, regular length like a phone number or national ID number is wasteful.