Hekaton works by providing in-application memory storage for the most often used tables in SQL Server. With a new tool that will be available in the new version of SQL Server, it will help identify tables that are most accessed, and will store them in the system’s main memory for faster access time. The rest of the data will still be stored in the traditional manner. The whole system will optimize queries and procedures, with Hekaton compiling T-SQL stored procedures in native code, so that the whole system runs faster.
Some eagle-eyed readers will see that this is very similar to other products that are currently available – like Oracle, xVelocity, or even Microsoft’s own PowerPivot and Power View. However, the biggest difference is that Hekaton is built directly into SQL Server, so that there are no extensions, downloads, or interfaces that can slow down the very program meant to help increase your speed.
Hekaton is currently being tested by a few very lucky developers, but will be available for all users in the new version of SQL Server, which is expected in 2014 or 2015.
Reference: Pinal Dave (https://blog.sqlauthority.com)