Statistics histograms explained through steps, RANGE_ROWS, EQ_ROWS, and DBCC SHOW_STATISTICS help connect data shape to plan estimates.
SQL Server Execution Plan Quiz: One Table, Two Operators
One table reference can produce Nested Loops, a Key Lookup and parallel operators in an execution plan. A controlled SQL example makes the work visible and shows why MAXDOP is a ceiling rather than a promise of parallel execution.
Star Schema Queries and How SQL Server Runs Them
Star schema queries join a large fact table to focused dimensions; learn bitmap filters, columnstore, and indexes that support the real workload.
Force a Plan With Query Store: Undo a Bad Plan in Minutes
Force a plan with Query Store when a query turns slow after a plan change. This post builds a regression, finds both plans in Query Store, forces the good one, measures what forcing costs and shows when to unforce.
When Auto Update Statistics Is Not Enough
Auto update statistics can miss important data patterns; inspect thresholds, ascending keys, sampling, and targeted update schedules.
Indexed View Quiz: The Table and Clustered Index Confusion
An indexed view and its base table can each own a clustered index because they are separate objects. Inspect both owners in a SQL example and see why a view index does not give its base table a second clustered index.
Finding the Nearest Location With a Spatial Index
A nearest location query in SQL Server needs TOP, STDistance in WHERE and ORDER BY, matching SRIDs, and a checked spatial plan.