I’m fairly new to MongoDB query optimizing. I have a query that runs quite slow when there are about 7000 not-too-complex documents from a single collection to be retrieved (about 5 to 6 MB of data). I’m using Node.js and Mongoose.
For analysis, I added some time measurements and also an additional “countDocuments” for comparison. However, the actual query needs to return all documents at once:
console.time('FullQuery') await MyMongooseModel.find(findCondition) console.timeEnd('FullQuery') console.time('OnlyCount') await MyMongooseModel.countDocuments(findCondition) console.timeEnd('OnlyCount')
Result I get on my local Node.js server connecting to a local Mongo installation running in a Docker container:
FullQuery: 821.835ms OnlyCount: 33.472ms
Connecting my local Node.js server to my remote Atlas instance:
FullQuery: 3.595s OnlyCount: 42.642ms
My interpretation of that data:
- Filtering is quite fast, 30-40ms is not a concern. Hence, adding additional indexes won’t help.
- The time difference between the local and the remote Mongo instance is huge: more than 2.5 seconds. I think that’s far more than it should take to transfer 6 MB of data through a rather fast internet connection. Hence, I think there might be some configuration problem.
I now have the questions below:
- Is my interpretation correct?
- Is there anything I can do to improve performance in general even locally? unfortunately, limiting the number of query results and/or projections to limit the properties is not really an option in my use case.
- What can I do to make the Atlas remote instance return the query faster?
- I know this is not a Mongoose help forum, but asking anyway: Could the problem be in Mongoose and/or the underlying Node.js driver?