Which two approaches should you implement?

Your application uses Cloud SQL for MySQL. Your users run reports on data that relies on near-real time; however, the additional analytics caused excessive load on the primary database. You created a read replica for the analytics workloads, but now your users are complaining about the lag in data changes and that their reports are still slow. You need to improve the report performance and shorten the lag in data replication without making changes to the current reports.

Which two approaches should you implement? (Choose two.)
A . Create secondary indexes on the replica.
B . Create additional read replicas, and partition your analytics users to use different read replicas.
C . Disable replication on the read replica, and set the flag for parallel replication on the read replica.
Re-enable replication and optimize performance by setting flags on the primary instance.
D . Disable replication on the primary instance, and set the flag for parallel replication on the primary instance. Re-enable replication and optimize performance by setting flags on the read replica.
E . Move your analytics workloads to BigQuery, and set up a streaming pipeline to move data and update BigQuery.

Answer: B, C

Explanation:

Replication lag and slow report performance. E is eliminated because using BigQuery would mean changes to the current reports. Report slowness could be the result of poor indexing or just too much read load (or both!). Since excessive load is mentioned in the question, creating additional read replicas and spreading the analytics workload around makes B correct and eliminates A as a way to speed up reporting. That leaves the replication problem. Cloud SQL enables single threaded replication by default, so it stands to reason enabling parallel replication would help the lag. To do that you disable replication on the replica (not the primary), set flags on the replica and optionally set flags on the primary instance to optimize performance for parallel replication. That makes C correct and D incorrect. https://cloud.google.com/sql/docs/mysql/replication/manage-replicas#configuring-parallel-replication