James is a big data and data warehousing technology specialist at Microsoft. He is a thought leader in the use and application of Big Data technologies, including MPP solutions involving hybrid technologies of relational data, Hadoop, and private and public cloud. Previously he was an independent consultant working as a Data Warehouse/Business Intelligence architect and developer. He is a prior SQL Server MVP with over 30 years of IT experience. James is a popular blogger (JamesSerra.com) and speaker, having presented at dozens of PASS events including the PASS Business Analytics conference and the PASS Summit. He is the author of the book “Reporting with Microsoft SQL Server 2012”. He received a Bachelor of Science degree in Computer Engineering from the University of Nevada-Las Vegas.
In SQL Server 2012, a new feature was added called Columnstore Indexes that resulted in huge query performance improvements. In SQL Server 2014, there have been two major improvements on this feature:
Clustered: They have enhanced the columnstore to be a pure columnar store, so indexing is no longer required. The In-Memory ColumnStore for data warehousing is implemented as a clustered columnstore index (or CCI) on a table. The data in a CCI is grouped and stored for every column in the table. Unlike the non-clustered columnstore index, the CCI is the data – there is no other underlying data structure
Updatable: You are able to insert, update, and delete data in an existing ColumnStore. Note that a columnstore index is impossible to update “in-place” due to its highly compressed structure, so “deltastores” are used. The same solution was done for v2 of PDW
Note you will still be able to create a non-clustered columnstore index which is not updatable. A table with a clustered columnstore index cannot have any type of nonclustered index.
CREATE COLUMNSTORE INDEX (Transact-SQL)
SQL SERVER 2014 – Columnstore Index Enhancement – Part 1
Clustered Columnstore Indexes – part 1 (“Intro”)
Updatable columnstore index, sp_spaceused and sys.partitions
SQL SERVER CLUSTERED COLUMNSTORE INDEXES AT TECHED 2013
Video What’s New for Columnstore Indexes and Batch Mode Processing
Enhancements to SQL Server Column Stores
What’s New for Columnstore Indexes in SQL Server 2014
ColumnStore Archival Compression–SQL Server 2014
New Enhanced Column Store Index in SQL Server 2014 – Part 1