Why Use MongoDB ObjectID Instead of createdAt?
MongoDB ObjectIDs are superior to traditional createdAt timestamp fields for several key reasons:
- Built-in timestamp: ObjectIDs contain a 4-byte timestamp representing creation time, eliminating the need for a separate createdAt field.
- Guaranteed uniqueness: ObjectIDs are globally unique across collections and databases, combining timestamp, machine identifier, process ID, and counter.
- Natural sorting: Documents sorted by _id are automatically sorted by creation time, making chronological queries more efficient.
- Storage efficiency: Using ObjectID eliminates the need for additional timestamp indexes, reducing storage overhead and improving performance.
- Atomic creation: The timestamp is embedded during document creation, ensuring consistency without additional database operations.
This approach reduces schema complexity while providing better performance and guaranteed temporal ordering.
