Q61 [Scenario]: How do you store and query hierarchical category tree structures (e.g., e-commerce categories) in MongoDB?
Common pattern models:
- Parent References: Each node stores
{ _id, name, parent: ObjectId }(fast updates). - Materialized Paths: Each node stores
{ _id, name, path: ',Electronics,Computers,Laptops,' }(fast sub-tree regex queries matching^,Electronics,Computers,). - Array of Ancestors: Each node stores
{ ancestors: [ObjectId1, ObjectId2] }.
Key Takeaways
- Materialized Paths enable fast sub-tree searches via regex index prefixing.
- Array of Ancestors facilitates fast breadcrumb rendering.
Knowledge Check
Which hierarchy modeling pattern stores ancestral paths as string paths for fast sub-tree regex searches?