In-Memory Database Architecture: An Overview

A comprehensive high-level run-down of in-memory systems.

Overview of In-Memory Technologies of Azure SQL Database

Azure SQL Database offers a straightforward approach to controlling its performance through vertical scaling. Despite its simplicity, scaling up has obvious pricing implications and, while it is an online operation, it might result in rollback of in-flight transactions. If you are looking for a supplemental approach to enhancing performance, then you might want to consider implementing in-memory technologies which are part of the Azure SQL Database feature set.

Index_ID of the PK in In-Memory-Tables