As you assess vendors offering high availability Postgres solutions, it's essential to understand the depth of their Postgres integration and the impact on your existing infrastructure. Below are the seven critical questions and considerations to guide you through this evaluation.
Understanding the foundation of a vendor’s claims about PostgreSQL compatibility is crucial. The level of integration with the original PostgreSQL code base varies significantly between products, impacting compatibility, support, and potential migration challenges.
Key questions to ask include:
Understanding these aspects will give you insight into the longevity, compatibility, and community support you can expect from the product.
PostgreSQL compatibility varies across three main levels: Wire Protocol Compatible, Syntax Compatible, and Fully PostgreSQL Based. Each level has different implications for application compatibility and code migration.
Wire Protocol Compatible
Products at this level use PostgreSQL's communication protocol to pass SQL commands between the client and server. However, they often lack true SQL syntax compatibility with PostgreSQL. This can lead to syntax errors or unexpected behaviors, as these products might not support standard PostgreSQL commands and semantics.
Syntax Compatible
Syntax-compatible products accept many PostgreSQL SQL commands and execute them with similar behavior. They may support common PostgreSQL functions, stored procedures, and languages. However, these products might still differ from PostgreSQL, leading to potential redevelopment for applications that rely on specific PostgreSQL features. Vendors often document these differences, which you should review to estimate potential code migration needs.
Fully PostgreSQL Based
Fully PostgreSQL-based products typically bundle standard PostgreSQL with additional extensions or patches to enable distributed operation. These products, such as pgEdge, retain the same syntax, semantics, and behaviors as standalone PostgreSQL. Because they are fully based on PostgreSQL, such products can leverage the entire PostgreSQL ecosystem, including extensions, tools, and community innovations.
PostgreSQL releases a major version each September or October, introducing innovations and performance improvements. When evaluating distributed PostgreSQL solutions, ask vendors how quickly they incorporate support for new PostgreSQL versions. Timely support for major releases is crucial for staying up-to-date with security patches, performance optimizations, and new features.
One of PostgreSQL’s strengths is its extensibility, with thousands of extensions available that can significantly expand its functionality. Popular extensions like PostGIS (for spatial data) and pgvector (for vector data) can transform PostgreSQL into specialized databases.
Assess the level of extension support provided by the distributed PostgreSQL product:
Determining the level of extension support will help you gauge whether the product meets your operational needs and avoids dependency on custom engineering from the vendor.
Distributed databases inherently impose certain limitations on PostgreSQL functionality, as data replication, partitioning, and fault tolerance introduce complexities. As such, some PostgreSQL features may behave differently or be partially supported in distributed implementations. Carefully review vendor documentation to understand these limitations and ensure they align with your application requirements.
One of the biggest benefits of using PostgreSQL is its active and vibrant community. This developer community fosters a steady stream of innovation and tool development that continually enhances PostgreSQL’s capabilities. Products that fully integrate with the PostgreSQL ecosystem can tap into these community-led advancements, giving users access to cutting-edge developments.
If a product is not fully based on PostgreSQL and instead relies on proprietary or isolated development, it may miss out on innovations from the community. Consider how much you value staying connected to the broader PostgreSQL ecosystem when choosing a solution.
Perhaps the most crucial aspect of your evaluation is assessing the level of effort required to migrate your applications to the distributed PostgreSQL solution. This can often be gauged by running a pilot project to migrate part or all of a key application to two or more shortlisted products.
By testing the migration process in a pilot, you can:
A thorough pilot test provides valuable insight into the real-world feasibility of the solution and helps prevent costly surprises later in deployment.
The above considerations offer a roadmap for evaluating distributed PostgreSQL vendors based on compatibility, extension support, and the anticipated migration effort. Choosing the right solution means balancing your need for high availability, fault tolerance, and compatibility with your existing PostgreSQL setup.
For a deeper dive into this topic, download the complete Distributed PostgreSQL Buyers Guide published by pgEdge.
This guide should provide you with a solid foundation for assessing distributed PostgreSQL vendors. Each question and consideration will guide you toward a solution that offers the right balance of compatibility, performance, and community support for your organization's high-availability database needs.
