Columnstore Indexes

The columnstore index is the standard for storing and querying large data warehousing fact tables. It uses column-based data storage and query processing to achieve up to 10x query performance gains in your data warehouse over traditional row-oriented storage, and up to 10x data compression over the uncompressed data size

A _columnstore index _is a technology for storing, retrieving and managing data by using a columnar data format, called a columnstore.

Columnstore indexes

• Are stored in memory
• Store data by column instead of by row
• Use compression to optimize memory usage and performace

Columnstore indexes can be clustered or non-clustered

• Clustered columnstore indexes include all columns
• Only one clustered columnstore index per table