Compare a good and a bad plan in Query Store using runtime history, SSMS Compare Showplan, estimates, joins, grants, and parallelism.
How to Disable Batch Mode in SQL Server? – Interview Question of the Week #252
My immediate reaction was why would you disable batch mode in SQL Server when it is really is an awesome feature for performance
Missing Index Suggestions: Three Checks Before You Create One
Review missing index suggestions against existing indexes, key order, and INCLUDE size before adding extra write overhead.
ABORT_QUERY_EXECUTION: Stopping a Runaway Query With a Query Store Hint
ABORT_QUERY_EXECUTION is a SQL Server 2025 Query Store hint that makes one known bad query fail before it uses any CPU. This post sets the hint, shows the exact error the caller gets, lists and clears the hint, and covers the traps: exact text, SET options and queries already running.
Sequence Project and Segment: How Window Functions Show Up in a Plan
A window function leaves Segment and Sequence Project operators in a query plan, and a Sort in front of them. This post tests ROW_NUMBER and a running total on SQL Server 2025, shows the batch mode Window Aggregate that replaces them, and removes the Sort with an index.
The Filter Operator: When SQL Server Reads Everything and Keeps a Few Rows
The Filter operator keeps a few rows after the plan has read and sorted many more. This post shows one on SQL Server 2025 with the actual plan and the logical reads, then rewrites the query so it seeks instead and reads about a fifth as many pages.
Capture Query Plans With Extended Events: A Safe, Scoped Session
To capture query plans without guessing, use an Extended Events session scoped to one database and a duration threshold. This post builds one on SQL Server 2025, reads the captured actual plan, and measures why plan capture must be switched on briefly and then off.