---
author: MikeRayMSFT
ms.author: mikeray
ms.reviewer: randolphwest
ms.date: 09/29/2024
ms.service: sql
ms.topic: include
---
> [!NOTE]  
> Documentation uses the term B-tree generally in reference to indexes. In rowstore indexes, the Database Engine implements a B+ tree. This does not apply to columnstore indexes or indexes on memory-optimized tables. For more information, see the [SQL Server and Azure SQL index architecture and design guide](../relational-databases/sql-server-index-design-guide.md).