Code Snippet - How to Add Index to Document at MongoDB C#

Table of Contents

1. Introduction
2. Add Index to a Document Field
3. Conclusion

Introduction

When working with MongoDB in C#, adding indexes to your document fields improves query performance. Below is a quick code snippet showing how to add an index to both a top-level document field and a subdocument field.

Add Index to a Document Field

// add index to document's field
collection.CreateIndex(IndexKeys.Ascending(_ => _.FieldName));
// add index to subdocument's field
collection.CreateIndex("SubDocument.FieldName");

Conclusion

Adding indexes to your MongoDB collections is essential for query performance. Use IndexKeys.Ascending for typed fields on documents and a string path for subdocument fields.