Is EnableOptimisticDirectExecution true or false by default?

[ajchalla]

Experimenting with ways to optimize our CosmosDB query charges -- Our data is partitioned by UserId and we mostly query in the context of a user (so it has to be single partition).

1. Would EnableOptimisticDirectExecution flag help reduce RUs for single partition queries?
2. Also, is this enabled by default or do we have to explicityly set to true in the QueryRequestOptions?

[Pilchie]

@adityasa - can you help out here?