Suggested indexes
- Currently it will suggest indexes that can't be created, such as with multiple array fields.
-- This should be detectable before suggesting an index.
-- Highlight array fields in the suggested index
- Include partial index expressions
- Make more than one suggestion for queries

Trying to create an index that contains multiple array fields (for some documents being indexed) won't fail until it hits one such document.
- Pre-parse to first confirm the fields being indexed don't include more than 1 array for the index?
- Pre-parse and inform the user if any of the fields are arrays for the index scope
- Pre-parse and make suggestions, like partial index expressions

Query execution planner
- It appears that the query execution planner doesn't take into account partial index expressions. E.g. there's a partial index expression enforcing field A = "abc" but you still need to include field A in the index for the planner to pick it.