Heimdall Database Proxy vs PgDoorman

Heimdall Database Proxy is a data access layer between an application and its database, routing, caching, and securing SQL queries. It can send reads to replicas and writes to primary databases, with replication-lag detection to support consistency. Frequently used queries can be cached with automatic expiry and invalidation rules to reduce database load and latency. Connection pooling can reduce front-side to back-side connections by up to a 1000:1 ratio. The proxy provides live SQL visibility, bottleneck identification, and auto-tuning recommendations, and can run as a transparent sidecar on-premise or in the cloud. Supported databases include MySQL, PostgreSQL, Amazon RDS, Oracle, SQL Server, MariaDB, DB2, Greenplum, and Redshift. Listed cloud integrations include AWS, Azure, Oracle, Google Cloud, and Redis. Active Directory integration supports authentication and authorization. Enterprise Plus includes data masking, GDPR auditing, and honey-tokens. A free Greenplum Community Edition is available for Greenplum use, with pooling, LDAP synchronization for one server, and SQL performance analytics. The AWS Marketplace listing offers a free 30-day trial; technical support for the Community Edition requires an Enterprise upgrade.

PgDoorman is a free, open-source, self-hosted PostgreSQL connection pooler written in Rust. It is described as a drop-in replacement for PgBouncer and Odyssey, and supports PostgreSQL 10 and newer on Linux or macOS. Listed capabilities include connection pooling, load balancing, and automatic failover; query routing is not supported. The pool coordinator enforces per-database connection caps and can reclaim idle capacity from pools with spare connections. Patroni-assisted fallback can direct new connections to another live cluster member during a switchover. Monitoring includes a Prometheus endpoint and an optional local diagnostic console for pool, latency, error, query, log, CPU, and memory information. Authentication includes MD5 or SCRAM passthrough, auth_query, PAM, JWT, Talos JWT, and pg_hba.conf rules. TLS is supported for client and backend connections. It can be built from source, installed from packages, or downloaded as a binary.