Create a Unique Email Index
Our user model declares email as unique.
For clarity, you can explicitly declare the index on the schema.
A unique index ensures that MongoDB does not allow multiple documents with the same indexed email value.
Existing duplicate records must be resolved before MongoDB can successfully create the index.
Index Deployment
In production, manage index creation through controlled database migrations or deployment procedures. Do not rely on automatic index creation for every application startup.
Define Email Index
userSchema.index(
{ email: 1 },
{ unique: true }
);Creates a unique ascending index on the email field.
Key Takeaways
Unique indexes enforce uniqueness at the database level.
Resolve duplicate records before index creation.
Manage production indexes deliberately.