Memory spike when using `find()`

Do you want to request a feature or report a bug? Report a bug

What is the current behavior? When I make a Model#find call with an $or operator, not only does the operation take ~5 minutes, it also takes up ~1 GB memory.

If the current behavior is a bug, please provide the steps to reproduce. My use-case:

  const result = await Guild.find({
    $or: [
      { premium: { $eq: true } },
      { prefix: { $ne: 'p!' } },
      { blacklistedChannels: { $exists: true, $ne: [], $type: 'array' } },
    ],
  });

Reproduction repo: https://github.com/almeidx/mongoose-memory-leak-repro

When I run node index.js on this repository:

Not sure if relevant but, here are my collection details:

• documents: 8360
• size: 38.71MB

What is the expected behavior? I expected it to not take ~5 minutes to process, but I can understand why it could take that long to process. What I really didn’t expect is the operation using ~1 GB of memory.

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that “latest” is not a version. 14.17.1, 5.12.15 and 3.6.8, respectively (I’m not sure if by ‘MongoDB’ you meant the mongodb npm module or the version of the database. I am using MongoDB Atlas version 4.4.6, mongodb npm module version 3.6.8)

[vkarpov15]

Managed to shave off another 5% in 5f9d7ba by reducing unnecessary key creation. In the future, we’ll investigate wrapping strictMode in a getter to see if that gives us a little more.

[vkarpov15]

No worries, glad you found a workaround. We’re going to keep working to try to improve our memory usage going forward, so thanks for your patience and for reporting this issue.