Answer to your last 3 questions : - Replace MySQL with MariaDB (hopefully your tables are InnoDB and the transition will be "relatively" seamless). You can con

Answer to your last 3 questions : - Replace MySQL with MariaDB (hopefully your tables are InnoDB and the transition will be "relatively" seamless). You can continue using the rest of your app as-is. - Yes. There are many by the simple fact that a lot of people are unaware of what they're really doing and what impact certain indexes, queries and even to some extent, compile-time options will introduce. - Schema is everything for an RDBMS. If people just take the time to calmly and carefully consider what it is they're trying to do and what options they'll truly need vs. just guessing what future "growth" would be like, they will have fewer actual (rather than imagined) growing pains later. Of course, most of these problems could be mitigated if new projects started off with Postgres or MariaDB, if they're taking the RDBMS route.