PgDog vs ProxySQL

PgDog is a PostgreSQL connection pooler, load balancer, and database sharder designed to scale databases without application changes. It multiplexes many application connections across fewer PostgreSQL server connections and supports SET, LISTEN/NOTIFY, and advisory locks. Read queries can be distributed across replicas while writes go to the primary, with health checks and failover detection. Sharding keys guide query routing; queries without a key can run across databases in parallel. Cross-shard transactions use PostgreSQL prepared transactions and two-phase commit, with automatic rollback on errors. PgDog can copy data and stream row changes to another database without pausing query traffic. Deployment options include Kubernetes Helm, Docker, AWS ECS Terraform, pre-built binaries, and source. Releases include Linux arm64 and amd64, Apple Silicon Mac, and Debian packages; the macOS binary is unsigned. The project is free and open source under AGPL-3.0, and documentation says internal use does not require sharing source code. Enterprise support includes architecture reviews, a dedicated Slack channel, and an SLA promising a response within 15 minutes.

ProxySQL is a self-hosted Linux database proxy for MySQL, PostgreSQL and related systems. It scales infrastructure without changes to the application stack or database engine, multiplexing more than 100,000 client connections through a few hundred backend connections. Protocol-aware, regex-based routing can send queries to primary servers, replicas or shards, and can route by user, schema or table. The proxy can cache results without application changes, monitor backend health and reroute traffic during failures. Query mirroring duplicates live traffic for analysis and performance testing, while percentage-based balancing supports gradual shifts. A database firewall is intended to protect against SQL injection and runaway queries. Deployment options include Linux packages, Docker and Kubernetes. ProxySQL is GPLv3-licensed open source, released in 2013. The Community plan is free and includes core features, supported platforms and community channels.