Migrated from AWS RDS to CockroachDB for a financial app - what broke

We moved our transaction reporting system from AWS RDS (Postgres) to CockroachDB last quarter. The sales pitch was all about horizontal scaling and high availability, which we really needed.

But wow, we hit some unexpected snags. Our basic reporting queries, which were fine on RDS, suddenly timed out. The biggest issue was with a daily summary view that uses `GROUP BY` on a date field – it just wouldn't finish. Support said our schema wasn't "optimized for distributed joins" and we needed to rework our indexes completely. It felt like we traded one set of problems for another. Has anyone else gone through this? I'm starting to wonder if we should have just scaled the RDS instance up instead.