Taming the Space Beast: Effective Strategies for Managing Unused Space in SQL Server

Several factors can contribute to unused space in your tables:

Scenario 1: Bulk Loading

-- Insert 1000 rows at once
INSERT INTO MyTable VALUES ('value1', 10), ('value2', 20), ...;

-- Delete some rows later
DELETE FROM MyTable WHERE id < 500;

This scenario might leave unused space even after deleting rows, as the extents used for the initial 1000 rows remain allocated.

Scenario 2: Index Rebuild

CREATE INDEX MyIndex ON MyTable(id);
-- Rebuild the index later
ALTER INDEX MyIndex ON MyTable REBUILD;

Rebuilding the index might not reclaim the space occupied by the previous version, leading to unused space.

Remember, the best approach depends on your specific situation and the root cause of the unused space. It's crucial to analyze the cause to determine the most efficient solution for your database.