Transactions in Redis - Read operations in another database

Question

We are trying to implement caching for our multi-tenant application. We are planning to create new Redis DB for each tenant.

We have one scenario where we need to use Redis Transactions. While going through this post https://redis.io/topics/transactions, we found that

All the commands in a transaction are serialized and executed sequentially. It can never happen that a request issued by another client is served in the middle of the execution of a Redis transaction. This guarantees that the commands are executed as a single isolated operation.

Is this read blocking will only apply to database level or at full instance level?

Answer 1

The guarantee you quoted applies to the instance, not the database. A command for DB 2 will not run in the middle of a transaction for DB 1.

You can find more information about multiple databases (including an argument by the creator of Redis against using them at all) in this question.