Lazy loading of selection set causing performance issues.

[padmapreethi-902117]

Hi,

We have developed a graphql service for one of our usecase (basically it calls multiple REST based Downstreams). There is no DB call involved. But at field resolver level, we check for selected fields and based on that we set the downstream request as well. But what we noticed is, this lazy computation of selection set is CPU intensive. When we don't check on the selection set, our supported RPS doubled.