Evaluating PostGraphile For Your Project

Hopefully you’ve been convinced that PostGraphile serves an awesome GraphQL API, but now let’s take a more critical look at whether or not you should adopt PostGraphile for your project.

PostGraphile’s audience is for people who want to prioritize their product. PostGraphile allows you to define your content model in the database as you normally would, however instead of building the bindings to the database (your API) PostGraphile takes care of it.

This takes a huge maintenance burden off your shoulders. Now you don’t have to worry about optimizing the API and the database, instead you can focus on just optimizing your database. Scaling a database is well-understood - and you can combine techniques - scaling vertically with larger database servers (more RAM, faster storage), or horizontally with read replicas.

No Lock-In

PostGraphile does not lock you into using PostGraphile forever - in fact most of the work you do implementing a PostGraphile API is in your database, which you can take with you if you chose to move to a different system, so no work is lost. If you feel comfortable with the cost of building your API, PostGraphile is simple to switch with a custom solution - you can even export the GraphQL SDL PostGraphile builds for you so you just need to implement your own resolvers.

PostGraphile does not ask you to do anything too divergent with your PostgreSQL schema, allowing you to take your schema (and all your data) to whatever solution you build next, and being confident that it was well designed - hand rolled by you! GraphQL itself provides a simple and clear deprecation path if you want to start using different fields. And of course with Graphile Engine plugins you can extend (or remove) functionality as you wish.

Further, you can migrate away from PostGraphile bit by bit by placing a GraphQL proxy in front of it and redirecting certain resolvers to your new solution. This enables you to move away from PostGraphile with zero downtime.

Ideally PostGraphile will scale with your company, however there is a simple exit path even years into the business. We welcome your contributions to help PostGraphile scale and meet your needs, and are very open to sponsored improvements to the software.

Schema Driven APIs

If you fundamentally disagree with a one-to-one mapping of a SQL schema to an API (GraphQL or otherwise) this section is for you.

First of all, PostGraphile is not necessarily meant to be the be-all and end-all of your API. PostGraphile was created to allow you to focus on your product and not the API. If you need to integrate external systems, there are plugin interfaces to help you do that, and they're getting easier to use all the time. If you want a custom API there is a simple transition path (read no lock in). If you still can’t get over the one-to-one nature of PostGraphile consider the following arguments why putting your business logic in PostgreSQL is a good idea:

  1. PostgreSQL already has a powerful user management system with fine grained row level security. A custom API would mean you have to build your own user management and security, and having to guarantee that every possible route to your database data is vetted by the same permissions logic (which PostgreSQL RLS does for you).
  2. PostgreSQL allows you to hide implementation details with views of your data. Simple views can even be auto-updatable. This provides you with the same freedom and flexibility as you might want from a custom API except more performant.
  3. PostgreSQL gives you automatic relations with the REFERENCES constraint and PostGraphile automatically detects them. With a custom API, you’d need to hardcode these relationships, which can become quite a chore!
  4. For what it’s worth, you can write in your favorite scripting language in PostgreSQL, including JavaScript and Ruby.
  5. If you don’t want to write your code inside PostgreSQL, you could also use PostgreSQL’s NOTIFY feature to fire events to a listening Ruby or JavaScript microservice (this could include email transactions and event reporting), implement a job queue, or add a Graphile Engine plugin to wrap or replace a PostGraphile resolver.

Still worried about a certain aspect of a schema driven API? Open an issue, we're confident we can convince you otherwise 😉

This article was originally written by Caleb Meredith.