Inspect the SQL Server plan cache, identify single-use plans and memory use, and understand what optimize for ad hoc workloads changes.
Why SQL Server Has No Result Cache: Buffer Pool and Plan Cache
A second run is faster, but SQL Server did not remember your answer. A tiny demo shows what really gets reused: pages and plans.
POC Index: Supporting Window Functions Without a Sort
Is a Sort slowing down your running totals? Build an index in partition, order, covering order and watch the Sort disappear from the plan.
Spotting tempdb Contention
Spot tempdb contention through PAGELATCH waits and allocation pages, then review file layout and current server settings before changing files.
Growing varchar Updates: How Longer Values Split Pages
A varchar column costs almost nothing while it is empty and a lot once people fill it in. Here is the page count before and after, and what a rebuild recovers.
How to Read a SQL Server Execution Plan
An execution plan is SQL Server showing its working. Read it inside out, learn the six operators you actually meet, ignore the cost percentages, and compare estimated rows with actual rows instead.
Stop Chasing Every Seek: When a Table Scan Is the Right Plan
A Clustered Index Scan is not always the problem. Count the reads for a seek with lookups, a scan and the optimizer’s own pick, then see when the seek really wins.