What is columnstore index and how is different from clustered and non-clustered

Question

Hi I am confused about columnstore index, what is column store index and how it is different from clustered and non-clustered index..

Answer 1

Clustered Columnstore Index is a new feature in SQL Server 2014. Columnstore index allows data to be stored in a columnar format instead of traditional row-based storage. Column store indexes (Non-clustered) were originally introduced in SQL 2012 to address high query performance under high volume requirements typical of Data warehousing/Reporting.

Major points:

1. It stores data in columnar data structure which aids reads very faster. Stores data in compressed format and hence your total IO cost will be very minimal.
2. Columnstore data structure is the same data structure where data and indexes everything stored, unlike data stored separately and indexes stored separately etc.,
3. It will be very useful for more columns table where you select only limited columns daily, for example if there is ProductSalesFact table, you normally select for this product what is the count of sales, or for this quarter what is the sales etc, Eventhough it has hundreds of columns it access only two required columns.

My blog on columnstore index which provide performance study of 300 million records with columnstore vs rowstore

https://sqlserver101.wordpress.com/2016/01/25/why-clustered-columnstore-index-in-sql-server-2014/

MSDN link for various versions of columnstore and paths:

https://msdn.microsoft.com/en-us/library/dn934994.aspx