For a big collection of documents, it is faster to execute 2 queries or use aggregations?

Working with Data
,
1

For a big collection of documents, it is faster to execute 2 queries (the paginated results and the total count) or it is faster to use aggregations?

Example aggregation query

[
        { $match: conditions },
        { $sort: { createdAt: -1 } },
        {
          $group: {
            _id: null,
            count: { $sum: 1 },
            results: { $push: "$$CURRENT" },
          },
        },
        {
          $project: {
            count: 1,
            results: { $slice: ["$results", 0, 10] },
          },
        },
      ]

I would appreciate it if you could give me an example

2

One round-trip to the database is always better than 2.

You may have 2 different queries using $facet.

You current aggregation will probably failed by exceeding some limits as you $push all documents of your collection before $slice’ing only 10 of them.

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3

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4

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