Implementing DataLoader with Apollo Server

Our GraphQL backend is sending too many small individual requests, uncovering an important performance issue. We’d like to batch these requests together to reduce the number of queries and improve our application’s performance.

We’ll see how we can use a DataLoader library with Apollo Server and significantly optimize our application in this lesson.

Using DataLoader

To use the DataLoader library, we first need to add it to our project.

npm install --save dataloader

The library functionality is implemented in the DataLoader type, allowing the batching of multiple queries in a single request. We need to specify how to fetch data in our application. To do this, we need to create an instance of DataLoader and pass a function that can fetch multiple objects given a list of keys.