Data replication from prod to read replicate in Azure SQL MI

Question

I am in middle of finalizing database for our company. Though I have gone through multiple readings but there are couple of questions which i am still confused at. We are planning to go ahead with Azure SQL MI (Business Critical) approach

1. My understanding is that BC Tier comes with read replica, is it true?

2. How does the replication happens between a prod instance and read replica, does this need to be manually managed or gets auto-taken care of by azure platform.

3. The plan is to use read replica for all the reporting use-caess. Is this correct approach?

4. What if there is data that needs to be imported from different data sources (could be sql, could be something else). Should those be inserted in prod instance and will get replicated to read replica? (this data is only needed for reporting)

Thanks

Answer 1

Please find the responses below:

1. Yes Read scale-out is always enabled in the Business Critical service tier of Managed Instance. We can however disable it based on need.
2. Changes made on primary are replicated to read-only replicas asynchronously, however this is taken care by azure and there is no manual intervention needed.
3. Read-replicas are very well suited for reporting purpose, this way some workload can be taken out from primary replica as well. However as mentioned that the sync between primary and read-replica is asynchronous you might not see the real time data. Latency between the primary replica and read-only replicas varies in the range from tens of milliseconds to single-digit seconds. However, there is no fixed upper bound on data propagation latency.
4. Yes any new data has to first be populated on primary or prod instance and then only it will be propagated or synced to read-replicas.

Referenced Article: Use read-only replicas to offload read-only query workloads