PgDog vs ShardingSphere-Proxy

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.

ShardingSphere-Proxy is a self-hosted database proxy that gives clients a database server interface over a binary protocol. Its listed client protocols are MySQL, PostgreSQL, openGauss, and Firebird. It distributes storage and computing across underlying databases through sharding, and provides distributed transactions with a hybrid XA and BASE engine. Read/write splitting balances reads using SQL semantics and awareness of database topology. Other capabilities include migration with sharding, federated queries, transparent encryption, and data masking.

You can deploy it from a binary distribution, as a Docker image, or with Helm. The binary requires Java JRE 8 or higher; Docker needs no additional dependency. For a MySQL backend, the Proxy ext-lib directory needs mysql-connector-j-8.4.0.jar. The project is free at free. Support for system databases and tables such as information_schema and pg_catalog is limited, and some graphical database clients may show errors.