I'm running a MySQL database with tens of tables in remote server. To monitor the data, I write a small program to query to database via VPN connection every 10 seconds. Each query is a union of 20+ select sub-queries from 20 different tables with the same structure. A server program receives data from external sources and writes thousands of records each second to a table I don't query.
What's the impact of my queries to the database? What if I query every second? Do they slow down the whole database notably or slow down the writing of the table I don't query?
Since the remote database is working in a production system, it is not allowed to stop working. Do my queries create any risk that might shut down the whole database?