I have a Django app that uses a locally hosted Piwik/Matomo instance for analytics. People recommend PostgreSQL for Python based apps, but I could only find documentation for setting up Matomo on MySQL and its derivatives. I tried running them on their separate recommended/required databases, but both sites are hosted on a single bottom tier VPS with low memory, and with two databases running it makes the memory situation worse. I know I can just switch Django to MySQL, but I’ve also noticed that MySQL uses more memory than PostgreSQL, so that’s what I’d ideally like to use for everything. Memory is the biggest limiting factor of my dirt cheap little server, so is it possible to switch Matomo to PostgreSQL in order to save some of those resources?
Matomo does only support MySQL (and MariaDB) and will do so for probably a very long time. Supporting PostgreSQL would mean rewriting (and even more importantly optimizing for it) a large part of Matomo which no one of the core team will be working on in the foreseeable future.
I don’t think either of MySQL and PostgreSQL use more memory and you can configure MySQL to exactly use as much memory as you want it to use.