Sync between databases

For example between search and main db.

When introducing another database, they need to be synced somehow
Easiest: write to both in app code (what if it fails and also makes it slower.)
Better to stream changes to other db. Queues. But if it's only like 10 a day, not worth it
Then you need to check for drifts over time

Depends how fast you need them synced, ie a daily dump could be enough or if you need to write to both straight away.