Let me give an overview of one of multi join Ad hoc query with couple of where condition, which I got received to improve the run time speed. I got a statement from a developer that one of code is running long time, more than 15+ hours, which usually runs in less than a minute. I have asked them how a less than minute code will run more than 15 hours, they said no changes made, I am sure they are lying and it is a Ad-hoc, I cannot trace the DDL changes. I started doing basic check and it is an eight table join with group by and order…