That per-second counter on your dashboard is probably a running total. Here is how to turn it into a real rate with two samples.
Approximate Percentiles With APPROX_PERCENTILE_CONT
Use APPROX_PERCENTILE_CONT for large response-time summaries, compare exact percentiles, and interpret the documented rank error bound.
Finding Schedule Clashes: Overlapping Sessions per Attendee
An attendee says two sessions run at the same time. Here is how to find every overlapping pair once, and why touching is not a clash.
Finding Queries That Spill With total_spills in Query Stats
Rank total_spills and recent counters, inspect plans, compare Query Store tempdb use, and investigate estimates before increasing grants.
Find Database File Latency – SQL in Sixty Seconds #198
Lots of people asked me to create a video on my earlier blog post SQL SERVER – Script to List Database File Latency. Here is the video.
MySQL Configuration Changes: Track What Changed and When
MySQL configuration changes explain many sudden slowdowns. See how innodb_read_ahead_threshold works, what MySQL 8.0 records about a change and how to keep your own history.
Database File Latency: Read and Write Stalls per IO
Database file latency is the stall time per read or write. This post divides the IO stall columns by the call counts for every file, explains the zero queued columns and says when a number is worth acting on.