OS threads by scheduler shows how many Windows threads each SQL Server scheduler owns. This post joins the scheduler, worker and thread views and counts them per CPU. It compares the counts with the server totals and explains the hidden schedulers that a careless query counts as CPUs.
rows_sampled: Checking How Much Data Your Statistics Saw
A fresh statistic can still come from a small sample. Compare rows with rows_sampled and see how a sample misjudges a rare value.
OS Thread of a Session: Map Session ID to Windows Thread ID
To find the OS thread of a session, join sys.dm_os_tasks to sys.dm_os_threads on the worker address. This post reads the map for your own session and for every user session. It explains why idle sessions have no row, why parallel queries have several, and how to follow a thread in Performance Monitor.
sys.dm_exec_valid_use_hints: Every USE HINT Your Server Knows
sys.dm_exec_valid_use_hints lists every USE HINT name that your SQL Server accepts. This post groups the 35 names on SQL Server 2025 and shows the compile error for a misspelled hint. It applies two hints and reads the plan to prove each one worked, then compares USE HINT with QUERYTRACEON.
JDBC and sendStringParametersAsUnicode: The Hidden Index Scan
Diagnose sendStringParametersAsUnicode conversions, align JDBC parameters with varchar indexes, and preserve required Unicode data.
Threads With Zero Rows in a Parallel Plan, Measured
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.