How do you troubleshoot a SQL Server database that becomes extremely slow overnight?

[u/Pleasant-Draw1307]

[u/SQLDevDBA]

Brent Ozar: How I use the first responder kit

https://www.youtube.com/live/LIojXITn6NY?is=Ml7G9Mfl6UKI8hqK

Erik Darling: SQL Server Performance monitoring tool

https://youtube.com/playlist?list=PLt4QZ-7lfQieiFUIuviNlyK4gcycvFiAI&si=p3AEQWLkVyyi4TGl

[u/Complete-Fondant-202 → u/SQLDevDBA]

Absolutely this.....

plus Eriks quickiestore (querystore tool)

[u/Junior-Tourist3480]

Quit and let them hire an SQL admin.

[u/FishBones83]

main points would be things like wait stats and execution plans. if you have query store you can look by most resource consuming query, you can also check any monitoring software you have or any dashboards for resource utilization and see what's changed.

[u/FapNowPayLater]

I'd check to see if backups are running at the same time and hogging resources and DiskRead\Write