---
title: "Master index"
slug: "master-index"
abstract: "Introduction to Sitecore Master index supported infrastructure, references, and privacy and security."
---
# Master index

The Master index contains a configurable subset of the content and media items in the [Master database](https://doc.sitecore.com/xp/en/developers/93/platform-administration-and-architecture/master-database.html "Master database").

## Supported infrastructure

You can host the Master index on:

- Solr
- Azure Search

Refer to the [Sitecore compatibility table](https://kb.sitecore.net/articles/087164) for compatible versions.

## Reference structure

The Master index has its place in the Sitecore reference structure. It can be referenced by other roles, and it can also reference other roles.

![Illustration showing the Master index's place in the Sitecore reference structure.](https://doc.sitecore.com/api/markdown-image/xp/en/developers/93/platform-administration-and-architecture/images/master.png)

### Referenced by

The Master index is referenced by the following roles:

- [Content Management](https://doc.sitecore.com/xp/en/developers/93/platform-administration-and-architecture/content-management--cm-.html "Content Management (CM)")
- [EXM Dispatch](https://doc.sitecore.com/xp/en/developers/93/platform-administration-and-architecture/exm-dispatch.html "EXM Dispatch")

### References

The Master index does not reference other roles.

## Privacy and security

Assuming default behavior, the Master index does not handle personal data.