This Locking and Blocking Quiz asks whether an update waits when it changes a different row than an open transaction. The answer depends on the index. A two-window test on SQL Server 2025 shows the wait, the lock that causes it, and two ways to remove it.
What Is In the Plan Cache and How to Look
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.