Question: Does async/await remove the benefits of DataLoader?

[graphql]

Question: Does async/await remove the benefits of DataLoader?

[matthewgertner]

@leebyron My colleague made a similar point to me. Presumably one major advantage of DataLoader is that it batches load calls when the occur on the same tick. If you say something like:

const foo = await dataLoader.load(...)
const bar = await dataLoader.load(...)
const baz = await dataLoader.load(...)

...then Node will execute each call in a separate tick and no batching will be possible (at least this is my understanding).

Am I misunderstanding something or do you just think that the convenience of await outweighs the benefits of batching?

[leebyron]

Just to follow up on this: async/await not only does not remove the benefits of DataLoader, it's actually a quite nice way to use DataLoader. async/await is a syntactic way to operate on Promises, and Promises are returned by the load() function.

[wincent]

@matthewgertner: Your understanding is correct. If you want the three loads to occur concurrently you will have to avoid the serial execution ordering that await imposes. In your example, you could use Promise.all:

const [foo, bar, baz] = await Promise.all([
  dataLoader.load(...),
  dataLoader.load(...),
  dataLoader.load(...),
]);

Note that this doesn't mean you can't use await at all, just that you have to be selective where and how you use it.

[matthewgertner]

Right, thanks for the clarification.