Need to filter on a number (exact) and avoid using $match

MongoDB Atlas Atlas Search
#1

As the doc says here : https://docs.atlas.mongodb.com/atlas-search/performance/#-match-aggregation-stage-usage

It’s not recommanded to use a $match in a $search query because it can drastically slow down query results.

In my case, I need to filter on a number field so I am using a compound search like this :

db.getCollection("movies").aggregate(
[
    {
        $search: {
            "index":"year",
            "compound": {
                "must": [{
                  "text": {
                    "query": "war",
                    "path": "plot"
                  }
                }],
                
                "filter": [{
                  "range": {
                    "path": "year",
                    "gte": 1980,
                    "lte":1980
                  }
                }]
              }
        }
    },
    {
        $project: {"title":1,"year":1,"countries":1,"plot":1}
    }
]

As you can see I want to filter my movies released only in 1980, so I’am using a range filter with gte=lte=1980.

It’s the only way I found to do this without using a $match stage (that ideed, decreases the perf), but I think this is not very elegant.

Is there another way ?

Thank you.

1 Like
#2

Hi there, PM from Atlas Search here! This query looks great to me! You could also use Equals in place of the range.

#3

That’s not what’s written in the docs :

The equals operator supports querying boolean and objectId values.

Here, I want to query a number field. If I replace range with equals it crashes.

#4

Right, that is my mistake, I glazed over that limitation. In that case the way you have it written is good.

Feel free to vote for this as a feature if that is interesting to you: The equals operator should support numeric datatypes – MongoDB Feedback Engine

We are considering it in the near future.

1 Like