MongoDB Aggregation Framework: Understanding $sort

Sort Employees by Department and Salary

Write an aggregation pipeline that sorts employees first by 'department' ascending, then by 'salary' descending.

Expected output: Documents ordered by department ascending and salary descending within each department.

Hint: Use $sort with multiple fields specifying 1 for ascending and -1 for descending.

Optimize Sorting with Indexes

Create an index on the 'age' field and write a pipeline that sorts users by age ascending after filtering users older than 25.

Expected output: Efficiently sorted users older than 25 by age.

Hint: Use $match before $sort and ensure an index exists on 'age'.

$sort orders the documents in the pipeline based on specified fields in ascending or descending order.

By creating indexes on the fields used in $sort and placing $match stages before $sort to reduce the dataset size.

Yes, $sort can sort by multiple fields by specifying each field and its sort order in the $sort document.