SQL Clone
SQLServerCentral is supported by Redgate
Log in  ::  Register  ::  Not logged in

SQL Server 2014 In-Memory OLTP (Hekaton) Limitations

One of the biggest new features in SQL Server 2014 is SQL Server In-Memory OLTP, known mostly by its code name of Hekaton (see SQL Server 2014: In-memory OLTP Engine, code-name: Hekaton).  Basically, this puts tables in memory, giving a potentially huge performance boost when accessing these tables, especially with writes (to perform your own performance testing, check out SQL Server 2014 CTP2 In-Memory OLTP Sample).  But be aware that there are currently many features that In-Memory OLTP does not support:

For memory-optimized tables, some of the features not supported are: IDENTIFY or SEQUENCE columns, foreign key constraints, check constraints, MERGE statement, DML triggers, XML/CLR/LOB data types, compression.

Also, with In-Memory OLTP you can natively compile stored procedures (with native_compilation), but the stored procedures can only access in-memory tables.  And there are many features that you cannot use inside a natively compile stored procedure, such as: cursors, CASE statement, CTEs, user-defined functions, UNION statement, PIVOT statement, DISTINCT statement, and many more.

See Transact-SQL Constructs Not Supported by In-Memory OLTP for a comprehensive list of what is not supported.

More info:


Exploring In-memory OLTP Engine (Hekaton) in SQL Server 2014 CTP1

SQL Server 2014 In-Memory OLTP Architecture and Data Storage

Natively Compiled Stored Procedures with SQL Server 2014

James Serra's Blog

James is a big data and data warehousing technology specialist at Microsoft. He is a thought leader in the use and application of Big Data technologies, including MPP solutions involving hybrid technologies of relational data, Hadoop, and private and public cloud. Previously he was an independent consultant working as a Data Warehouse/Business Intelligence architect and developer. He is a prior SQL Server MVP with over 30 years of IT experience. James is a popular blogger (JamesSerra.com) and speaker, having presented at dozens of PASS events including the PASS Business Analytics conference and the PASS Summit. He is the author of the book “Reporting with Microsoft SQL Server 2012”. He received a Bachelor of Science degree in Computer Engineering from the University of Nevada-Las Vegas.


Leave a comment on the original post [www.jamesserra.com, opens in a new window]

Loading comments...