So, installing Moodle with MySQL is simple enough, and works really well. However, what if you need to scale beyond the capabilities of MySQL? Is Postgres the next best thing? What about others - Mongo, Oracle, etc.
What about clustering MySQL databases... anyone tried that with Moodle? Any hints and tips on building huge sites? I am looking at a potential 100K users for a set up, and wondering whether to break this into smaller sections, use multiple Moodle installations or whether to see if one large and powerful database can cope,