How do you find outdated statistics? The honest answer is that ‘outdated’ is subjective. I explain why, and how I look at statistics instead.
SQL SERVER – The NOLOCK Question – Notes from the Field #117
NOLOCK is one of the most abused hints I see. In Notes from the Field #117, Stuart Ainsworth explains when Nolock makes sense and why overusing it is risky.
SQL SERVER – Three Simple Guidelines for System Maintenance – Notes from the Field #098
Notes from the Field #098: three simple guidelines for system maintenance. Automate what you can, document the rest, and always validate.
SQL SERVER – Basic Statistics Maintenance – Notes from the Field #083
Statistics help the SQL Server engine pick an optimal plan. This Notes from the Field episode covers the basics of statistics maintenance every DBA should know.
SQL SERVER – Reading Statistics IO Data
I start every tuning exercise with Statistics IO. Here is how to read its output: scan count, logical reads, physical reads and read-ahead reads per table.
SQL SERVER – What is Filtered Statistics?
Filtered statistics, added in SQL Server 2008, help the optimizer estimate rows when data is correlated. Here is a small demo with Employee and Sales tables.
Cardinality Estimation and Performance: SQL in Sixty Seconds #072
Cardinality estimation and performance depend on each other: the optimizer guesses a row count, and that guess picks the plan and sets the reads. This post tests one query under the old and the new estimator on SQL Server 2025, shows where the new guess wins and where it loses, and explains how to switch estimators with the smallest possible change.