Function overhead

Does Fauna do any optimizations to reduce any lookup or deserialization overhead for user-defined functions? Does it keep the most used in memory? Thanks.

Fauna’s query coordinator keeps resources in a cache to re-use when possible. However, Fauna is a shared service: the “most used” (in most cases) doesn’t mean “your most used”. As well, queries are distributed in round-robin fashion to an available node in a replica, so the in-memory cache for a particular node very often won’t contain your UDF even when nobody else’s queries intervene.

Where possible, Fauna performs lazy evaluation and applies short-circuit behavior (such as in And, Or, and Not calls.

Beyond that, UDFs have to be fetched from storage (like any other document). Reaching consensus and manipulating storage is going to be a lot more overhead than parsing the UDF and executing it.