What Is a Columnstore Indexes in Microsoft SQL Server?
Stores values by column in compressed rowgroups. Batch-mode execution and segment elimination can accelerate analytical scans and aggregates.
How the Columnstore Indexes Algorithm Works
Stores values by column in compressed rowgroups. Batch-mode execution and segment elimination can accelerate analytical scans and aggregates.
When to Use Columnstore Indexes
Large fact tables and queries reading a subset of columns across many rows.
How to Create a Microsoft SQL Server Columnstore Indexes
Review data quality, existing structures, feature support, build time, and deployment requirements before creating an index on a production table.
CREATE NONCLUSTERED COLUMNSTORE INDEX IX_Sales_Columnstore ON dbo.Sales (SaleDate, ProductId, Quantity, Amount);Columnstore Indexes Query Example
This example demonstrates the matching query shape. Check the execution plan to confirm that the engine can use the index.
SELECT ProductId, SUM(Amount) FROM dbo.Sales WHERE SaleDate >= '2026-01-01' GROUP BY ProductId;Queries Supported by Columnstore Indexes
Large fact tables and queries reading a subset of columns across many rows. A similar-looking predicate may not use the same access path; operators, expressions, key order, and data type all matter.
Read Performance, Storage, and Write Costs
Small point lookups may not benefit; rowgroup quality, deletes, and load patterns matter. Indexes reduce some search work but require storage and add maintenance to writes.
Columnstore Indexes Limitations and Common Mistakes
Clustered/nonclustered options and update capabilities vary by server version and edition.
Do not assume that an index being present means the optimizer chose it or that the query became selective.
How to Measure and Tune Columnstore Indexes
Inspect batch mode, rowgroup state, segment elimination, compression, and load behavior.
Compare representative plans and timings before and after, including concurrent writes and realistic data volumes.
Columnstore Indexes Questions
Will the database always use this index?
No. The optimizer weighs selectivity, estimated costs, statistics, cache state, and the amount of data returned.
What should I verify before production?
Confirm version support, query compatibility, write overhead, build/rollback procedures, and index behavior during backup and recovery.
Official Microsoft SQL Server Index Documentation
Check Microsoft Learn: SQL Server Indexes for release-specific requirements and supported operators.