Out of pure boredom and tired of all these Chat websites selling my data and with ChatGPT's new update on ads - I decided enough was enough and created my own Chat application for privacy. Like every other architect, I searched for a good database and eventually gave up on specialized ones for chat because they were either too expensive to host or too complex to deal with. So, I simply just used PostgreSQL. My chat app has basic RAG, not ground breaking or anything - but the most important feature I made was ability to add different chat models into one group chat. So, when you ask for opinions on something - you are not relying on just a single model and you can get a multi-model view of all the possible answers. Each model can have its own unique prompt within the group chat. So basically, a join table.

Months passed by since this application was developed (a simple Phoenix/Elixir backend), and yesterday I was casually checking my database to see how many rows it had - about 500,000+ roughly. I didn't notice a single hint of the volume the Postgres was handling, granted - I'm the only user, but there's always a lot going on - RAG, mostly that requires searching of the database for context before multiple agents send you a response (and respond amongst themselves). Absolutely zero performance degradation.

I'm convinced that Postgres is a killer database that doesn't get the attention it deserves over the others (for chat). Already managing some high traffic websites (with over 500M+ requests) with no issues, so I am extremely unsurprised that it works really well for chat apps at scale too.