SPQR review
A focused self-hosted choice for PostgreSQL sharding and distributed transactions.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
SPQR is self-hosted, open-source database proxy software for teams scaling PostgreSQL horizontally through sharding. It sits between applications and PostgreSQL shards, uses the PostgreSQL protocol, and routes queries according to configured sharding rules and key ranges. The product is aimed at developers comfortable with PostgreSQL who want to keep sharding logic out of application code, particularly when databases are well partitioned and workloads are dominated by single-shard OLTP operations.
Its strongest area is the depth of its PostgreSQL sharding workflow. SPQR supports single-column and composite sharding keys, reference tables replicated across shards, and connection pooling in session and transaction modes. Distributed transaction commit strategies include two-phase commit, while data migration and workload balancing support changes across shards. A coordinator provides dynamic configuration, and multiple router instances can share cluster metadata through etcd. Prometheus metrics export adds a path for monitoring the proxy within an existing observability setup.
SPQR fits teams that want an open-source PostgreSQL router with routing, pooling, coordination, migration, and distributed transaction capabilities in one focused system. The self-hosted model gives those teams control over deployment and operations, but it also makes infrastructure management part of the product decision. PostgreSQL is the supported database, with PostgreSQL and etcd forming the stated ecosystem fit. Choose SPQR when horizontal PostgreSQL scaling and shard-aware routing are central requirements. Consider another option if the priority is a multi-database proxy or a broader platform centered on capabilities beyond PostgreSQL sharding and distributed transactions.
SPQR pros and cons
- Where it wins
- Routes PostgreSQL queries using single-column or composite sharding keys
- Supports pooling, reference tables, and distributed transaction strategies
- Adds coordinator-based configuration, migration, balancing, and Prometheus metrics
- Where it doesn't
- Self-hosted deployment requires PostgreSQL infrastructure management
- Designed for PostgreSQL rather than multiple database engines
- Its focus is sharding and routing, not a broad database platform
SPQR fact sheet, pricing and score →
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