Which DBMS?
1A. If MS SQL, they have tools which can both predict the execution plan and tools which monitor active servers.
1B. If MySQL/MariaDB, InnoDB or MyISAM?
Are you joining on indexes/PKs?
Yep MS SQL. Where can I find these tools and what are they called?
I'll need to check on Tuesday (as its not my code) but I dont think so. Would this slows things down?