How to apply a filter, before running MongoDB Atlas full text search?

Question

According to the documentation about Atlas Search, it states:

$search must be the first stage of any pipeline it appears in.

Well if that is the case, how do you apply Mongo filters. It seems very counter-intuitive to apply these filters on the output of the search?

We are thinking about using Mongodb full text search as an alternative to Algolia, but this limitation seems weird 🧐

Current pipeline:

const pipeline = [
    {
        $search: {
            text: {
                query,
                path: fields,
                fuzzy: {
                    maxEdits: 1,
                    maxExpansions: 50,
                },
            },
        },
    },
    {
        $match: {
            someField: 1,
        },
    },
];

Answer 1

In this case, it may be better to index someField in Atlas Search as a number, as it supports numeric types using the range operator and compound to combine the results. Since the entire query is run in Lucene, it should return results quicker.

const pipeline = [
    {
        $search: {
            compound: {
                should: {
                    text: {
                        query,
                        path: fields,
                        fuzzy: {
                            maxEdits: 1,
                            maxExpansions: 50,
                        },
                    },
                },
                filter: {
                    range: { 
                        path: "someField",
                        lte: 1,
                        gte: 1
                    }
                }
            }

        }
    }
];