A logical read requests a database page through the buffer cache. A customer asked about that measure after my STATISTICS IO video.
SQL SERVER – 3 Different Ways to Set MAXDOP
There are 3 different MAXDOP scopes: instance, database and statement. Readers of my 16-versus-1 demonstration asked where to configure it.
SQL SERVER – PREEMPTIVE Waits and Scheduler Context
Preemptive waits can measure work outside SQL Server cooperative scheduling. A customer asked about their increase during a health check.
Multiple OPTIMIZE FOR Hints in One Query: Value or UNKNOWN
Multiple OPTIMIZE FOR hints in one query are written as one list: each parameter gets its own value or UNKNOWN. This post compiles the same query six ways, reads the compile values and estimated rows from the plan cache, and shows which combinations SQL Server accepts.
Uniquifier: The Hidden Cost of Duplicate Clustered Keys
The uniquifier is a hidden 4-byte value that SQL Server adds to duplicate keys in a non-unique clustered index. This post measures its real cost row by row on SQL Server 2025 and shows it on the page. It also compares it with a unique key you choose yourself.
Scan Count Zero in STATISTICS IO: What the Number Means
Scan count zero in STATISTICS IO is not an error and not a free read. This post runs nine small queries and shows what 0, 1, 2 and 5 mean, why a unique lookup counts as zero, and why logical reads are the number to compare.
Alerting on Long-Running Queries With a SQL Agent Job
Alert on long-running queries with a five-minute SQL Agent job, a deduplicated log, and one Database Mail notice per new request.