Aggregates

PostGraphile's engine has support for powerful aggregates. The @graphile/pg-aggregates module adds various aggregates to the schema, and gives you the ability to add more via plugins. Aggregates are located under connection fields.

Aggregates ignore pagination info

Aggregates are performed over the entire collection represented by the field and its filters - not just the data that would be returned if you were to query the nodes. This means they ignore the first, last, before, after and offset arguments. This is deliberate (if you only need aggregates over the data that matches your pagination information then you could calculate these on the client).

Aggregates only work on Relay connection

Thanks to their expansibility, relay connections were the perfect place to add aggregates support. If you're using a behavior configuration that prefers lists over connections (e.g. -connection +list) then you can override it on a per-collection basis with the @behavior +connection smart tag.