Most of these are way better and I didn’t quite bring down production. I am a neophyte DB user (working in Finance, not IT.). I once wrote a query to try and a

Most of these are way better and I didn’t quite bring down production. I am a neophyte DB user (working in Finance, not IT.). I once wrote a query to try and abstract a simple table of about 8 years of dates by calendar month, fiscal month, holiday, etc (fiscal was different than calendar.). I ran a fairly open query in our oracle 12 dB. I waited about 20 mins and had no results so I figured I’d let it run overnight after I left for the day. When I got in the next morning, it was still running and people were having issues with getting their sales data and much of the sales reports didn’t run overnight. A few hours later I got an email from a DB admin I worked with closely on custom pulls and she was like wtf. Apparently the way I wrote the query I really killed the performance of the database and it broke lots on of processes. My badge of honor from that situation is the email from the DB admin that was the forward of a long email trail of the IT folks trying to figure out what happened with the subject “Nasty Query”. I saved it and occasionally share it with people.