I finally decided to create a video on that topic on my SQL in Sixty Seconds Channel. I will create more videos on the topic Wait Stats for Performance.
Waits Since Restart: A Wait Stats Query With Uptime Rates
Waits since restart show where a SQL Server spends its waiting time. One query ranks the real waits, removes the idle ones, and adds the average wait, the signal share and a rate per hour of uptime. A table maps the common waits to the area to check next.
COUNT(*), COUNT(column) and COUNT(DISTINCT): Basics That Trip People
Why do two counts of the same table disagree? Five tiny demos show NULL, blank text, LEFT JOIN placeholders, bigint and join multiplication.
SQL SERVER – Find Untrusted Foreign Key
An Untrusted Foreign key has not validated all existing rows. A customer bulk-load history prompted this inventory.
RESOURCE_SEMAPHORE vs THREADPOOL: Two Waits, Two Fixes
RESOURCE_SEMAPHORE vs THREADPOOL tells you whether a task waits for memory or for a worker thread. This post reads both counters and checks for live waits. A demo shows how an index shrinks a memory grant from 38,216 KB to zero.
Index Build Speed: Which Rebuild Settings Change the Time
Index build speed depends on rebuild or reorganize, MAXDOP, ONLINE, SORT_IN_TEMPDB and the recovery model. This post times each choice on a million row table and measures the log under each recovery model. It shows which one changes the clock and which changes only the log.
Forwarded Records, Multiple Backup and SSMS – SQL in Sixty Seconds – Feb 2021
This month’s SQL in Sixty Seconds topics were Forwarded Records, Multiple Backup and SSMS. Here are the videos released in Feb 2021.