What is indexing in MongoDB? How is it different from SQL indexes? Indexing in MongoDB is a mechanism to improve query performance by reducing the

mount of data the system needs to scan. MongoDB creates indexes on fields that are

queried frequently.

Differences from SQL indexes:

• MongoDB uses B-tree indexes (by default) but also supports other types like

hashed indexes, geospatial indexes, and text indexes.

• SQL indexes are typically built on a fixed schema and are more rigid, while MongoDB

indexes can be dynamic, allowing indexing on any field within a document.

• MongoDB supports compound indexes and array indexes for more complex

queries.