PG requires a lot of expertise to keep running when you get to a billion rows or massive ingest. It can do it, but it doesn't just do it out of box running the defaults.
Hopefully at 1B records, you have a business model that allows you to spend some money on either hardware or talent to solve this problem.
Hopefully at 1B records, you have a business model that allows you to spend some money on either hardware or talent to solve this problem.