This post is how the database born in small business, today is impossible managed big data whit simple SQL Basic , this information and database is the year 2007
SQL is common find stores procedures https://en.wikipedia.org/wiki/Stored_procedure
for check proc i find this query
A small database (<10 GB) is possible work whit SQLEXPRES, this is a database
Whit a POS installer , only modify the SYSDBINFO, and creatre a login for user psa.
Another project to practice in MySQL is http://blog.xcero.xyz/site/
Is a Online Store , this connection if in PHP and try to practice how to show item description and price