Single service comparison

Azure SQL Database is engine-bound to Microsoft SQL Server and T-SQL, so portability hinges on a SQL Server-compatible target. Huawei RDS offers a Microsoft SQL Server engine option for like-for-like T-SQL workloads, while GaussDB is Huawei's own openGauss-based distributed database (PostgreSQL-family) and is not a SQL Server replacement; treat them as addressing different workload variants, not interchangeable targets. Assess whether the application requires SQL Server fidelity or can accept a rewrite to openGauss syntax before choosing.

Scaling and HA models differ materially. Azure SQL Database provides zone-redundant active geo-replication and configurable service objectives without exposing replicas, whereas Huawei RDS for SQL Server uses primary/standby and read replica topologies with manual failover, and GaussDB offers distributed HA with up to 1000+ nodes and city-level RPO=0. Azure's purchasing is vCore/DTU/serverless; Huawei bills instance specs (vCPU/memory), storage, backup, and DRS task usage separately, so TCO must be recomputed against peak load and retention rather than assumed equivalent.

Operational responsibility and ecosystem integration diverge. Azure SQL Database couples to Azure Monitor, Microsoft Entra ID, Defender for SQL, and database-scoped automation; Huawei RDS/GaussDB integrate with Cloud Eye, Database Security Service (DBSS), Data Admin Service (DAS), IAM, and KMS, with a different control-plane API surface and T-SQL feature coverage that is not guaranteed at parity. Validate control plane, data plane, agent, backup/restore, and security equivalence for every workload before cutover, since neither Huawei target positions itself as a drop-in SQL Server clone.

Start with engine and version assessment. If the workload must remain T-SQL, target Huawei RDS for SQL Server and validate version, collation, contained database, T-SQL surface area, and managed-instance feature gaps against the source. If the application can be re-platformed to a distributed PostgreSQL-family database, target GaussDB and use Database Schema Converter UGO for pre-migration evaluation and automated syntax conversion. Pick one target per workload; do not assume dual-target portability.

For data and schema migration, use UGO to assess and convert schema and DRS to perform online heterogeneous migration with full plus incremental capture and minimal downtime. Confirm DRS supports the specific source SQL Server version and target engine in its supported-databases matrix before committing, and plan object filtering, character set mapping, and unsupported-object handling. Application connection strings, drivers, and authentication (for example, Microsoft Entra-backed identities) must be reworked to Huawei IAM and the target engine's client libraries.

Validate with DRS data comparison and workload replay before cutover: run query-level parity tests, backup/restore drills, and failover exercises on the RDS or GaussDB primary/standby topology, and verify RTO/RPO against your SLA. Then perform incremental sync to the cutover point and switch the application with a rollback path retained. Re-establish observability through Cloud Eye and DBSS, since Azure Monitor alerts and Defender for SQL findings do not map automatically.

Recalculate TCO and account for gaps. Azure SQL Database bundles availability, automated backups, and point-in-time restore in the vCore/DTU price; Huawei generally bills RDS/GaussDB instance, storage, backup retention, and DRS task usage separately, with cross-region DR and DBSS as added cost. Re-price for peak load, backup retention, and egress, and document any unsupported Azure-native features (elastic pools, Microsoft Entra authentication, SQL Database Ledger) that must be replaced or dropped.