HeliosProxy vs SPQR

HeliosProxy is a self-hosted, programmable PostgreSQL data-plane for routing connections, handling failover, replaying traffic, and supporting database upgrades. It provides session, transaction, and statement pooling, with multiplexing up to 100:1. Routing can account for replica lag, workload type, and failing backends through circuit breaking. Cache options include local memory, Redis-backed storage, and semantic tiers, with invalidation when writes occur. Transaction Replay can move sessions to a new primary and optionally replay reads or transactions when conditions permit, although prepared statements, temporary tables, open cursors, advisory locks, and extended-protocol SET statements are not restored. A WebAssembly plugin runtime offers five hook points, Ed25519 verification, and OCI distribution. The admin console includes topology, plugin, chaos, shadow-execution, and traffic-replay panels. Authentication supports JWT, OAuth 2.0, LDAP, and API keys. HeliosProxy works with PostgreSQL 12+ and compatible databases, and deployment documentation covers Docker, Kubernetes, and standalone setups. It is open source under Apache 2.0 and costs nothing.

SPQR is a self-hosted query router for horizontally scaling PostgreSQL through sharding. It can extract a sharding key from a query and route it to the relevant key range and shard when possible; keys can use one column or several. Queries can also specify a key or shard in a SQL comment. Applications connect using the PostgreSQL protocol, and the router and coordinator provide administrative consoles accessible through psql. SPQR supports one-phase and two-phase commit strategies; two-phase commit provides atomicity across shards and requires max_prepared_transactions greater than zero on each shard. The system can move data between shards to balance workload, and the project describes reducing transferred ranges to limit locking impact. Its documentation includes Docker and configuration-file deployment instructions. SPQR is free and distributed under the PostgreSQL Global Development Group License. The FAQ cautions that it is not suited to complex cross-shard queries, transactions modifying multiple shards or OLAP workloads, and reports a roughly 10–30% performance drop versus vanilla PostgreSQL depending on workload.