What are some examples of aggregation framework in MongoDB?

What are some examples of aggregation framework in MongoDB?

The aggregation framework in MongoDB is used for processing data and returning computed results. For example, you can use it to group data by a specific field and calculate averages.

Can you show me a specific example of a query?

Sure! Here's a simple example: db.orders.aggregate([ { $group: { _id: "$customerId", total: { $sum: "$amount" } } } ]) which groups orders by customer ID and sums their amounts.

What other stages can I use in aggregation?

You can use stages like $match, $sort, $project, and $limit to filter, sort, and reshape your data.

How do I optimize my aggregation queries?

To optimize aggregation queries, ensure you have appropriate indexes on the fields used in $match and $group stages.