LEARN. PRACTICE. GROW.Concept and mechanism
The Azure SQL family offers different levels of control and responsibility. An operating-system access requirement can lead to SQL Server on a VM with additional patching and availability management. PaaS reduces platform work but requires compatibility validation. Elastic pools share resources across databases; sizing depends on aggregate demand, especially when peaks coincide. Serverless with pausing can save idle compute, but resumption must match the required first-request experience.
Guided application
Separate lag-tolerant queries from those confirming a recent write. Read replicas should not be treated as instantly identical state in every session. For already-replicated logical errors, assess historical recovery and reconciliation of later valid changes. In a private design, confirm DNS, connectivity, and disabling the public path; a private endpoint alone does not complete isolation.
Four databases need 60 units simultaneously. With 30 headroom units, 270 units are needed, not merely one database’s peak.
Common pitfalls
Treating pooling as infinite capacity; using failover as data undo; selecting migration without checking OS dependencies.
Related topics: Storage and data integration · Continuity and demonstrated recovery
Choose guarantees per flow, including how to correct invalid state.
Reference: Azure SQL service comparison · AZ-305 objectives 2026-04-17