SQL Server Data Compression - Basics for Beginners


Data compression in SQL Server is a valuable technique for optimizing storage and improving query performance. In this beginner's guide, we'll explore the basics of data compression, its benefits, and provide sample code snippets to help you get started with implementing data compression in SQL Server.


Why Use Data Compression?

Data compression offers several advantages:


  • Storage Reduction: Compressed data occupies less space, leading to reduced storage costs.
  • Improved I/O Performance: Smaller data sizes result in faster I/O operations, enhancing query performance.
  • Backup and Restore Efficiency: Compressed backups and restores are quicker and require less storage.

Types of Data Compression

SQL Server supports two types of data compression:


  • Row-Level Compression: Compresses data at the row level, suitable for tables with varying data.
  • Page-Level Compression: Compresses data at the page level, beneficial for homogeneous data and tables.

Enabling Data Compression

Let's enable data compression for a table named "MyTable" using page-level compression:


-- Enable page-level compression
USE MyDatabase;
ALTER TABLE dbo.MyTable
REBUILD PARTITION = ALL
WITH (DATA_COMPRESSION = PAGE);

Monitoring Data Compression

You can monitor the status of data compression for tables using the following query:


-- Check compression status
SELECT t.name AS TableName, p.data_compression_desc
FROM sys.tables AS t
INNER JOIN sys.partitions AS p ON t.object_id = p.object_id;

What's Next?

As you become more familiar with SQL Server data compression basics, explore advanced topics like row-level compression, index compression, and best practices for determining which tables and indexes benefit the most from compression.