The KILL command terminates a connection thread by ID along with the related active query, if there is one. Then, to identify queries for deletion, you need to see processes on the server - and the SHOW PROCESSLIST command will be a fine solution. It's not an elegant way to fix database issues, but rather an effective last resort tool. There are 4 major reasons for that:

• If a long-running query holds other transactions from executing your more relevant query
• If a large number of faulty queries block viable queries
• If there are orphan processes after a client was disconnected from a server
• 'Too many connections' message

None of these scenarios are great, so before executing KILL, make sure other solutions have been tried. But once you know the KILL method is necessary, you will have a few different options. But in this particular guide, we will focus on the more 'intuitive' way of showing and killing faulty queries using simple commands. You should keep in mind that KILL has two modifiers - CONNECTION and QUERY. KILL CONNECTION is essentially the same as KILL, while KILL QUERY terminates only the query for the specified connection ID and leaves the connection itself intact.

Read in full: https://www.devart.com/dbforge/mysql/studio/show-running-queries-in-processlist.html