A parallel plan can show threads with zero rows, and that is normal. This post reads the per-thread row counters of two real plans on SQL Server 2025 and shows where the empty threads come from. It also says when an empty thread points to a real problem.
USE HINT: Switching Off One Optimizer Rule Without Trace Flags
Apply USE HINT to one query, inspect supported names, compare optimizer behavior, and manage Query Store hints with a clear removal plan.
Top 1 and Index Scan: A Scan That Stops After One Row
Top 1 and index scan can sit in the same plan, and the scan still reads only a few pages. This post runs six queries on a table of 100,000 rows and reads their logical reads. It shows why TOP 1 reads three pages in one case and every page in another.
Cached Data Per Object in Memory: Read the Buffer Pool
Cached data per object tells you which tables and indexes fill the buffer pool. This post builds two demo tables, empties their cache and reads part of the data. A query then lists the pages, megabytes and share of each index in memory. It also explains why the view is costly on a big server.
Disable Adaptive Join for One Query or a Whole Database
To disable adaptive join for one query, add a USE HINT to it. This post also shows a Query Store hint for code you cannot edit and the database setting that switches the feature off for everything. Each switch is tested on a small demo database and checked in the plan.
Enable Adaptive Join in SQL Server: Why It Does Not Appear
To enable adaptive join in SQL Server, the compatibility level, the database setting and the query must all agree. This post builds a demo database and probes the plan under each condition. It also corrects older advice whose statements switch the feature off.
Adaptive Threshold Rows: How an Adaptive Join Chooses
Adaptive threshold rows is the row count at which an adaptive join switches from nested loops to a hash join. This post runs two queries on WideWorldImporters, reads each threshold from the cached plan, and shows which branch ran. The first query stays below its threshold and the second goes above it.