SQL Server 2016 is Here!
IntroductionSQL Server 2016 is the latest addition to Microsoft’s data platform, with a variety of new features and enhancements that deliver breakthrough performance, advanced security, and richer, integrated reporting and analytics capabilities. Built using the new rapid-release model, SQL Server 2016 incorporates many features introduced first in the cloud in Microsoft Azure SQL Database. Furthermore, SQL Server 2016 includes the capability to dynamically migrate historical data to the cloud.
SQL Server 2016 General Availability Announcement with Rohan Kumar
Introducing Microsoft SQL Server 2016 leads you through the major changes in the data platform, whether you are using SQL Server technology on-premises or in the cloud, but it does not cover every new feature added to the platform. Instead, we explain key concepts and provide examples for the more significant features so that you can start experiencing their benefits firsthand.
SQL Server 2016 novelties
When users want data, they want it as fast as you can give it to them. Microsoft SQL Server 2016 includes several options for enabling faster queries. Memory-optimized tables now support even faster online transaction processing (OLTP) workloads, with better throughput as a result of new parallelized operations. For analytic workloads, you can take advantage of updateable, clustered columnstore indexes on memory-optimized tables to achieve queries that are up to one hundred times faster. Not only is the database engine better and faster in SQL Server 2016, but enhancements to the Analysis Services engine also deliver faster performance for both multidimensional and tabular models. The faster you can deliver data to your users, the faster they can use that data to make better decisions for your organization.
In-Memory OLTP enhancements
Introduced in SQL Server 2014, In-Memory OLTP helps speed up transactional workloads with high concurrency and too many latches by moving data from disk-based tables to memory-optimized tables and by natively compiling stored procedures.
In-Memory OLTP in SQL Server 2016
Sql Server 2016 Evolution Part 1
Reviewing new features for memory-optimized tables
In SQL Server 2016, you can implement the following features in memory-optimized tables:
- FOREIGN KEY constraints between memory-optimized tables, as long as the foreign key references a primary key.
- CHECK constraints.
- UNIQUE constraints.
- Triggers (AFTER) for INSERT/UPDATE/DELETE operations, as long as you use WITH NATIVE_COMPILATION.
- Columns with large object (LOB) types—varchar(max), nvarchar(max), and varbinary(max).
- Collation using any code page supported by SQL Server.
- Indexes for memory-optimized tables now support the following features:
- UNIQUE indexes.
- Index keys with character columns using any SQL Server collation.
- NULLable index key columns.
SQL Server 2016 introduces three new principal security features—Always Encrypted, Row-Level Security, and dynamic data masking. While all these features are security related, each provides a different level of data protection within this latest version of the database platform. Throughout this chapter, we explore the uses of these features, how they work, and when they should be used to protect data in your SQL Server database.
Always Encrypted is a client-side encryption technology in which data is automatically encrypted not only when it is written but also when it is read by an approved application. Unlike Transparent Data Encryption, which encrypts the data on disk but allows the data to be read by any application that queries the data, Always Encrypted requires your client application to use an Always Encrypted–enabled driver to communicate with the database. By using this driver, the application securely transfers encrypted data to the database that can then be decrypted later only by an application that has access to the encryption key. Any other application querying the data can also retrieve the encrypted values, but that application cannot use the data without the encryption key, thereby rendering the data useless. Because of this encryption architecture, the SQL Server instance never sees the unencrypted version of the data. Note At this time, the only Always Encrypted–enabled drivers are the .NET Framework Data Provider for SQL Server, which requires installation of .NET Framework version 4.6 on the client computer, and the JDBC 6.0 driver. In this chapter, we refer to both of these drivers as the ADO.NET driver for simplicity.
In a world that is always online, maintaining uptime and streamlining maintenance operations for your mission-critical applications are more important than ever. In SQL Server 2016, the capabilities of the AlwaysOn Availability Group feature continue to evolve from previous versions, enabling you to protect data more easily and flexibly and with greater throughput to support modern storage systems and CPUs. Furthermore, AlwaysOn Availability Groups and AlwaysOn Failover Cluster Instances now have higher security, reliability, and scalability. By running SQL Server 2016 on Windows Server 2016, you have more options for better managing clusters and storage. In this chapter, we introduce the new features that you can use to deploy more robust high-availability solutions.
AlwaysOn Availability Groups
First introduced in SQL Server 2012 Enterprise Edition, the AlwaysOn Availability Groups feature provides data protection by sending transactions from the transaction log on the primary replica to one or more secondary replicas, a process that is conceptually similar to database mirroring. In SQL Server 2014, the significant enhancement to availability groups was the increase in the number of supported secondary replicas from three to eight. SQL Server 2016 includes a number of new enhancements that we explain in this section:
- AlwaysOn Basic Availability Groups
- Support for group Managed Service Accounts (gMSAs)
- Database-level failover
- Distributed Transaction Coordinator (DTC) support
- Load balancing for readable secondary replicas
- Up to three automatic failover targets
- Improved log transport performance
Improved database engine
In past releases of SQL Server, Microsoft has targeted specific areas for improvement. In SQL Server 2005, the storage engine was new. In SQL Server 2008, the emphasis was on server consolidation. Now, in SQL Server 2016, you can find enhanced functionality across the entire database engine. With Microsoft now managing more than one million SQL Server databases through its Database as a Service (DBaaS) offering—Microsoft Azure SQL Database—it is able to respond more quickly to opportunities to enhance the product and validate those enhancements comprehensively before adding features to the on-premises version of SQL Server. SQL Server 2016 is a beneficiary of this new development paradigm and includes many features that are already available in SQL Database. In this chapter, we explore a few of the key new features, which enable you to better manage growing data volumes and changing data systems, manage query performance, and reduce barriers to entry for hybrid cloud architectures.
Sql Server 2016 Evolution Part 2
SQL Server 2016 introduces a new hybrid feature called Stretch Database that combines the power of Azure SQL Database with an on-premises SQL Server instance to provide nearly bottomless storage at a significantly lower cost, plus enterprise-class security and near-zero management overhead. With Stretch Database, you can store cold, infrequently accessed data in Azure, usually with no changes to application code. All administration and security policies are still managed from the same local SQL Server database as before.
Understanding Stretch Database architecture
Enabling Stretch Database for a SQL Server 2016 table creates a new Stretch Database in Azure, an external data source in SQL Server, and a remote endpoint for the database, as shown in Figure 4-7. User logins query the stretch table in the local SQL Server database, and Stretch Database rewrites the query to run local and remote queries according to the locality of the data. Because only system processes can access the external data source and the remote endpoint, user queries cannot be issued directly against the remote database.
Security and Stretch Database
One of the biggest concerns about cloud computing is the security of data leaving an organization’s data center. In addition to the world-class physical security provided at Azure data centers, Stretch Database includes several additional security measures. If required, you have the option to enable Transparent Data Encryption to provide encryption at rest. All traffic into and out of the remote database is encrypted and certificate validation is mandatory. This ensures that data never leaves SQL Server in plain text and the target in Azure is always verified.
Broader data access
A common challenge with data management is deciding how to handle changes to the data. At a minimum, you need an easy way to resolve an accidental change without resorting to a database restore. Sometimes you must be able to provide an audit trail to document how a row changed over time and who changed it. If you have a data warehouse, you might need to track historical changes for slowly changing dimensions. Or you might need to perform a trend analysis to compare values for a category at different points in time or find the value of a business metric at a specific point in time.
To address these various needs for handling changes to data, SQL Server 2016 now supports temporal tables, which were introduced as a new standard in ANSI SQL 2011. In addition, Transact-SQL has been extended to support the creation of temporal tables and the querying of these tables relative to a specific point in time.
A temporal table allows you to find the state of data at any point in time. When you create a temporal table, the system actually creates two tables. One table is the current table (also known as the temporal table), and the other is the history table. The history table is created as a page-compressed table by default to reduce storage utilization. As data changes in the current table, the database engine stores a copy of the data as it was prior to the change in the history table.
The use of temporal tables has a few limitations. First, system versioning and the FileTable and FILESTREAM features are incompatible. Second, you cannot use CASCADE options when a temporal table is the referencing table in a foreign-key relationship. Last, you cannot use INSTEAD OF triggers on the current or history table, although you can use AFTER triggers on the current table.
PolyBase was introduced in SQL Server 2014 as an interface exclusively for Microsoft Analytics Platform System (APS; formerly known as Parallel Data Warehouse), with which you could access data stored in Hadoop Distributed File System (HDFS) by using SQL syntax in queries.
In SQL Server 2016, you can now use PolyBase to query data in Hadoop or Azure Blob Storage and combine the results with relational data stored in SQL Server. To achieve optimal performance, PolyBase can dynamically create columnstore tables, parallelize data extraction from Hadoop and Azure sources, or push computations on Hadoop-based data to Hadoop clusters as necessary. After you install the PolyBase service and configure PolyBase data objects, your users and applications can access data from nonrelational sources without any special knowledge about Hadoop or blob storage.
SQL Server 2016 - Polybase
You can install only one instance of PolyBase on a single server, which must also have a SQL Server instance installed because the PolyBase installation process adds the following three databases: DWConfiguration, DWDiagnostics, and DWQueue. The installation process also adds the PolyBase engine service and PolyBase data movement service to the server.
Before you can install PolyBase, your computer must meet the following requirements:
- Installed software: Microsoft .NET Framework 4.5 and Oracle Java SE RunTime Environment (JRE) version 7.51 or higher (64-bit)
- Minimum memory: 4 GB
- Minimum hard-disk space: 2 GB
- TCP/IP connectivity enabled
To install PolyBase by using the SQL Server Installation Wizard, select PolyBase Query Service For External Data on the Feature Selection page. Then, on the Server Configuration page, you must configure the SQL Server PolyBase engine service and the SQL Server PolyBase data movement service to run under the same account. (If you create a PolyBase scale-out group, you must use the same service account across all instances.) Next, on the PolyBase Configuration page, you specify whether your SQL Server instance is a standalone PolyBase instance or part of a PolyBase scale-out group. As we describe later in this chapter, when you configure a PolyBase scale-out group, you specify whether the current instance is a head node or a compute node. Last, you define a range with a minimum of six ports to allocate to PolyBase.
Scaling out with PolyBase
Because data sets can become quite large in Hadoop or blob storage, you can create a PolyBase scale-out group, as shown in Figure 5-9, to improve performance.
A PolyBase scale-out group has one head node and one or more compute nodes. The head node consists of the SQL Server database engine, the PolyBase engine service, and the PolyBase data movement service, whereas each compute node consists of a database engine and data movement service. The head node receives the PolyBase queries, distributes the work involving external tables to the data movement service on the available compute nodes, receives the results from each compute node, finalizes the results in the database engine, and then returns the results to the requesting client. The data movement service on the head
node and compute nodes is responsible for transferring data between the external data sources and
SQL Server and between the SQL Server instances on the head and compute nodes.
Better and faster analytics capabilities have been built into SQL Server 2016. Enhancements to tabular models provide greater flexibility for the design of models, and an array of new tools helps you develop solutions more quickly and easily. As an option in SQL Server 2016, you can now use SQL Server R Services to build secure, advanced-analytics solutions at enterprise scale. By using R Services, you can explore data and build predictive models by using R functions in-database. You can then deploy these models for production use in applications and reporting tools.
In general, tabular models are relatively easy to develop in SQL Server Analysis Services. You can build such a solution directly from a wide array of sources in their native state without having to create a set of tables as a star schema in a relational database. You can then see the results of your modeling within the design environment. However, there are some inherent limitations in the scalability and complexity of the solutions you can build. In the latest release of SQL Server, some of these limitations have been removed to better support enterprise requirements. In addition, enhancements to the modeling process make controlling the behavior and content of your model easier. In this section, we review the following enhancements that help you build better analytics solutions in SQL Server 2016:
- More data sources accessible in DirectQuery mode
- Choice of using all, some, or no data during modeling in DirectQuery mode
- Calculated tables
- Bidirectional cross-filtering
- Formula bar enhancements
- New Data Analysis Expressions (DAX) functions
- Using DAX variables
R is a popular open-source programming language used by data scientists, statisticians, and data analysts for advanced analytics, data exploration, and machine learning. Despite its popularity, the use of R in an enterprise environment can be challenging. Many tools for R operate in a single-threaded, memory-bound desktop environment, which puts constraints on the volume of data that you can analyze. In addition, moving sensitive data from a server environment to the desktop removes it from the security controls built into the database.
R Services in SQL Server 2016
Installing and configuring R Services
To use SQL Server R Services, you must install a collection of components to prepare a SQL Server instance to support the R distribution. In addition, each client workstation requires an installation of the R distribution and libraries specific to R Services.
R Services is available in the Standard, Developer, and Enterprise editions of SQL Server 2016 or in Express Edition with Advanced Services. Only the Enterprise edition supports execution of R packages in a high-performance, parallel architecture. In the server environment, you install one of the following components from the SQL Server installation media:
- R Services (In-Database) A database-engine feature that configures the database service to use R jobs and installs extensions to support external scripts and processes. It also downloads Microsoft R Open (MRO), an open-source R distribution. This feature requires you to have a default or named instance of SQL Server 2016.
- R Services (Standalone) A standalone component that does not require a database-engine instance and is available only in the Enterprise edition of SQL Server 2016. It includes enhanced R packages and connectivity tools from Revolution Analytics and open-source R tools and base packages. Selection of this component also downloads and installs MRO.
For report developers, Reporting Services in SQL Server 2016 has a more modern development environment, two new data visualizations, and improved parameter layout options. In addition, it includes a new development environment to support mobile reports. Users also benefit from a new web portal that supports modern web browsers and mobile access to reports. In this chapter, we’ll explore these new features in detail.
What's New in Microsoft SQL Server 2016 Reporting
Report content types
This release of Reporting Services includes both enhanced and new report content types:
- Paginated reports Paginated reports are the traditional content type for which Reporting Services is especially well suited. You use this content type when you need precise control over the layout, appearance, and behavior of each element in your report. Users can view a paginated report online, export it to another format, or receive it on a scheduled basis by subscribing to the report. A paginated report can consist of a single page or hundreds of pages, based on the data set associated with the report. The need for this type of report continues to persist in most organizations, as well as the other report content types that are now available in the Microsoft reporting platform.
- Mobile reports In early 2015, Microsoft acquired Datazen Software to make it easier to deploy reports to mobile devices, regardless of operating system and form factor. This content type is best when you need touch-responsive and easy-to-read reports that are displayed on smaller screens, communicate key metrics effectively at a glance, and support drill-through to view supporting details. In SQL Server 2016, users can view both paginated and mobile reports through the web portal interface of the on-premises report server.
- Key performance indicators (KPIs) A KPI is a simple type of report content that you can add to the report server to display metrics and trends at a glance. This content type uses colors to indicate progress toward a goal and an optional visualization to show how values trend over time.
Improved Azure SQL Database
Microsoft Azure SQL Database was one of the first cloud services to offer a secure, robust, and flexible database platform to host applications of all types and sizes. When it was introduced, SQL Database had only a small subset of the features available in the SQL Server database engine. With the introduction of version V12 and features such as elastic database pools, SQL Database is now an enterprise-class platform-as-a-service (PaaS) offering. Furthermore, its rapid development cycle is beneficial to both SQL Database and its on-premises counterpart. By integrating new features into SQL Database ahead of SQL Server, the development team can take advantage of a full testing and telemetry cycle, at scale, that allows them to add features to both products much faster. In fact, several of the features in SQL Server 2016 described in earlier chapters, such as Always Encrypted and Row-Level Security, result from the rapid development cycle of SQL Database.
Introduction to SQL Database
Microsoft Azure SQL Database is one of many PaaS offerings available from Microsoft. It was introduced in March 2009 as a relational database-as-a-service called SQL Azure, but it had a limited feature set and data volume restrictions that were useful only for very specific types of small applications. Since then, SQL Database has evolved to attain greater parity with its on-premises predecessor, SQL Server. If you have yet to implement a cloud strategy for data management because of the initial limitations of SQL Database, now is a good time to become familiar with its latest capabilities and discover how best to start integrating it into your technical infrastructure.
Elastic database features
Microsoft has introduced elastic database features into SQL Database to simplify the implementation and management of software-as-a-service (SaaS) solutions. To optimize and simplify the management of your application, use one or more of the following features:
- Elastic scale This feature allows you to grow and shrink the capacity of your database to accommodate different application requirements. One way to manage elasticity is to partition your data across a number of identically structured databases by using a technique called sharding. You use the elastic database tools to easily implement sharding in your database.
- Elastic database pool Rather than explicitly allocate DTUs to a SQL Database, you can use an elastic database pool to allocate a common pool of DTU resources to share across multiple databases. That way you can support multiple types of workloads on demand without monitoring your databases individually for changes in performance requirements that necessitate intervention.
- Elastic database jobs You use an elastic database job to execute a T-SQL script against all databases in an elastic database pool to simplify administration for repetitive tasks such as rebuilding indexes. SQL Database automatically scales your script and applies built-in retry logic when necessary.
- Elastic query When you need to combine data from multiple databases, you can create a single connection string and execute a single query. SQL Database then aggregates the data into one result set.
Managing elastic scale
Sharding is not a new concept, but it has traditionally been challenging to implement because it often requires custom code and adds complexity to the application layer. Elastic database tools are available to simplify creating and managing sharded applications in SQL Database by using an elastic database client library or the Split-Merge service. These tools are useful whether you distribute your database across multiple shards or implement one shard per end customer, as shown in Figure 8-7.
You should consider sharding your application if either of the following conditions apply:
- The size of application data exceeds the limitations of SQL Database.
- Different shards of the database must reside in different geographies for compliance, performance, or geopolitical reasons.
Below are some additional resources that you can use to find out more information about SQL Server 2016.