Heimdall Database Proxy vs PgBouncer

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.

PgBouncer is a self-hosted connection pooler for PostgreSQL. It reuses server connections to lessen the performance cost of opening new ones, and offers session, transaction, and statement pooling. Statement pooling does not allow multi-statement transactions. PgBouncer can send connections to databases on different hosts, but it has no built-in multi-host load balancing or failover detection; DNS round-robin, external TCP load balancers, DNS changes, or external tools are described as alternatives. It can track protocol-level prepared statements in transaction and statement modes when max_prepared_statements is non-zero. Authentication options include client certificates, SCRAM-SHA-256, LDAP, PAM, and HBA-based configuration. The features page lists default memory needs of 2 kB per connection. PgBouncer is free, with source releases and references to native packages and RPM and Debian repositories. It runs on Linux and Windows; MinGW is the documented supported Windows build environment. Building requires Libevent 2.0 or later, pkg-config, and a C11-capable compiler; TLS support also requires OpenSSL.