COLUMNSTORE INDEX
COLUMNSTORE INDEX is a SQL statement in the Indexes category. Columnstore indexes store data column-wise instead of row-wise. Excellent for data warehouse/analytics queries. The syntax is CREATE NONCLUSTERED COLUMNSTORE INDEX idx_name ON table (columns);. It returns columnstore index. A typical example: CREATE TABLE sales_facts ( product_id INT, sale_date DATE, amount DECIMAL(10,2), region VARCHAR(50) ); -- Add columnstore index for analytics: CREATE NONCLUSTERED COLUMNSTORE INDEX cs_sales ON sales_facts (product_id, sale_date, amount, region); -- Queries that benefit: SELECT region, SUM(amount) AS total_sales FROM sales_facts WHERE sale_date BETWEEN '2026-01-01' AND '2026-06-01' GROUP BY region; -- Columnstore: only reads region, amount, sale_date columns -- vs Rowstore: reads entire rows -- Compression: columnstore compresses better (5-10x)… A close relative is CREATE INDEX, which creates an index on one or more columns to speed up query performance. A close relative is DROP INDEX, which removes an existing index from a table. A close relative is COMPOSITE INDEX, which an index on multiple columns. Column order matters — queries use leftmost prefix.