mongodb Questions
2 months ago
MongoDB aggregation: how to efficiently join two collections?
I have two collections: orders and customers. I want to fetch all orders along with the customer's name and email.
// orders: { _id, customerId, total, status }
// customers: { _id, name, email }I tried $lookup but it's killing performance on large datasets (~2M orders). Should I be using indexes differently, or is there a better aggregation strategy?
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Priya Nair
asked 2 months ago
1
Answers
51
Upvotes
5670
Views2 months ago
Docker: container can't connect to MongoDB running on host machine
I'm running a Node.js app inside Docker and trying to connect to a MongoDB instance running on my host machine. The connection string mongodb://localhost:27017 fails inside the container.
Error: connect ECONNREFUSED 127.0.0.1:27017I know localhost inside Docker refers to the container itself. How do I properly connect to the host's MongoDB?
3 months ago
MongoDB: when to embed documents vs using references?
I'm designing a schema for a blog platform. I have posts, comments, and users. I can't figure out when to embed vs reference:
- Should comments be embedded in the post document or a separate collection?
- If a post can have thousands of comments, embedding seems dangerous for document size
- But referencing requires multiple queries
What are the rules of thumb here?
S
Sofia Greco
asked 3 months ago2
Answers110
Upvotes