Get distinct records values

db.test.aggregate([{$group: {_id: "$name", salary: {$max: "$salary"}}}])

should list all names with their salaries.

$max returns the highest salary per element. You could also choose $first etc, see https://docs.mongodb.com/manual/reference/operator/aggregation/group/#accumulator-operator.

You can also use a distinct sentence with filtered collection. For example, you can get distinct values of names from salaries over 800 with the following query:

db.test.distinct("name", { "salary": { $gt: 800 } })

You can use db.collection.distinct to get back an array of unique values:

> db.test.distinct("name")
[ "my_name", "john" ]