SQL Server In-Memory OLTP is a powerful engine integrated into the SQL Server Engine (version 2014 and later), optimized for Online Transaction Processing (OLTP). This article helps you getting started with this amazing technology.
An Introduction to SQL Server In-Memory OLTP
In-Memory OLTP (codenamed “Hekaton”) is a powerful engine which is fully integrated into SQL Server’s Database Engine and introduces new data structures for optimizing the performance of OLTP workloads. So, you can have memory-optimized tables, natively-compiled stored procedures, memory-optimized table variables, etc.
In-Memory OLTP offers a significant performance boost when it comes to processing large amounts of information, especially in data environments with high levels of concurrency.
In this series of articles, we will see in plain words, how we can take advantage of this technology and start using it for boosting performance of heavy workloads.
In this first article, we are going to see how easy is to create an In-Memory OLTP-enabled database and memory-optimized tables.
How to Create a SQL Server In-Memory OLTP-Enabled Database
OK, enough talking, let’s see some code! The below T-SQL script creates a new In-Memory OLTP-enabled database.
--create database CREATE DATABASE InMemOLTPDB; GO --use the database USE InMemOLTPDB; GO --add memory-optimized file group to the database ALTER DATABASE InMemOLTPDB ADD FILEGROUP InMemOLTPDB_mofg CONTAINS MEMORY_OPTIMIZED_DATA; --add file for memory-optimized objects --you can set any path you like - in this example: c:memoptdata --if the directory does not exist you will need to create it ALTER DATABASE InMemOLTPDB ADD FILE (name='InMemOLTPDB_mofg1', filename='C:memoptdataInMemOLTPDB_mofg1') TO FILEGROUP InMemOLTPDB_mofg; --set the isolation level for memory-optimized tables to SNAPSHOT ALTER DATABASE InMemOLTPDB SET MEMORY_OPTIMIZED_ELEVATE_TO_SNAPSHOT=ON; GO
How to Create Memory-Optimized Tables in SQL Server
Now you can create memory-optimized tables.
When creating memory-optimized tables you have two options:
- Option 1: You can create a durable memory-optimized table which means that in the case of server crash or failover the data will be available as they will be recovered from transaction logs.
- Option 2: You can create a non-durable table which means that in the case of a server crash or failover the data in the table will be lost.
The below script creates a sample durable memory-optimized table:
--Memory-Optimized Table: Durable CREATE TABLE [dbo].[Person_Durable] ( ID INT NOT NULL PRIMARY KEY NONCLUSTERED HASH WITH (BUCKET_COUNT = 1000), FirstName VARCHAR(50) NOT NULL, LastName VARCHAR(50) NOT NULL, Remarks VARCHAR(50) NOT NULL, )WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_AND_DATA); GO
The below script creates a sample non-durable memory-optimized table:
--Memory-Optimized Table: Non-Durable CREATE TABLE [dbo].[Person_Non_Durable] ( ID INT NOT NULL PRIMARY KEY NONCLUSTERED HASH WITH (BUCKET_COUNT = 1000), FirstName VARCHAR(50) NOT NULL, LastName VARCHAR(50) NOT NULL, Remarks VARCHAR(50) NOT NULL, )WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_ONLY); GO
Stay tuned as in the next article we are going to run some simple experiments with In-Memory OLTP and get an indication on the performance benefits.
What are your views on the subject? Feel free to comment!
- Introducing In-Memory Optimization in SQL Server
- Introducing In-Memory OLTP Simulator
- In-Memory Optimization in SQL Server: Will my Workload Execute Faster?
- In-Memory OLTP Simulator – A Tool that helps you benchmark SQL Server’s Memory-Optimized Tables against your own workload
- Simple Experiment with SQL Server In-Memory OLTP is 79 Times Faster