explain
["explain", <query>]
=> <query-plan>
["explain", ["select", "people"]]
=> ["collection-scan", "people"]
["explain", ["select", "people", {"where": ["=", "name", "Bob"], "order": ["age", "asc"]}]]
=> ["sort", ["age", "asc"],
["index-lookup", ["people", "name", "Bob"]]]
Returns the query plan that will used by the database to execute the given query.
query must be on of select, count, update, or delete.