Row and Page Compression in Azure SQL

Microsoft SQL Server, Azure SQL Database, and Azure SQL Managed Instance offer row and page compression for rowstore tables and indexes. This feature not only conserves storage space but also enhances the performance of I/O-heavy workloads. It achieves this by reducing the number of pages required to store data, which in turn minimizes the number of pages that queries must retrieve from disk. However, it's important to note that data compression necessitates additional CPU resources on the database server for the compression and decompression processes as data is transferred to and from the application. In this session, we'll delve into the process of how Azure SQL implements data compression through the column descriptor format. We will also explore the impact of compression on overall system performance and learn about side effects such as page splits etc. so that you can decide whether compression improves the performance of your database.