Contrary to some of the sibling responses, my experience with pgvector specifically (with hundreds of millions or billions of vectors) is that the workload is q

Contrary to some of the sibling responses, my experience with pgvector specifically (with hundreds of millions or billions of vectors) is that the workload is quite different from your typical web-app workload, enough so that you really want them on separate databases. For example, you have to be really careful about how vacuum/autovacuum interacts with pgvector’s HNSW indices if you’re frequently updating data; you have to be aware that the tables and indices are huge and take up a ton of memory, which can have knock-on performance implications for other systems; etc.