1. Preparing the Server

Before you initiate the SQL Server 2012 installation process there are several pre-installation tasks that need to be completed to guarantee a successful SQL Server 2012 deployment. Some of the pre-installation tasks include verifying that the hardware, software, and network configurations are optimal to deploy SQL Server 2012 as well as having a good understanding of the SQL Server 2012 editions and the hardware and feature limitations imposed on each edition.

This section discusses planning and design considerations for a successful SQL Server 2012 deployment.

Hardware and Software Requirements

An important step to define hardware requirements is to make sure all the minimum hardware, software, and operating system requirements are met for a successful SQL Server 2012 installation. This step is critical in order to pass hardware validation checks during installation process and to ensure that performance and response time requirements are met. Table 1 lists the minimum hardware, software, and operating system requirements.

Table 1 Minimum Hardware Requirements

Proper Patching

SQL Server 2012 requires that the operating system and software components are updated to the proper service pack level. Table 2 lists the required service pack and the corresponding download link.

Table 2 Operating System and Software Patches

Firewalls

As part of the deployment process, Database Administrators need to work along with Network Administrators to ensure that network firewalls are configured to allow inbound and outbound traffic to the SQL Server instance. If a network firewall is not properly configured, connections to SQL Server instances and related services will be blocked. Table 3 lists the default ports for common SQL Server 2012 Services.

Table 3 Default Ports for Common SQL Server 2012 Services

2. Selecting the Edition

Selecting the right SQL Server Edition is another important consideration in the deployment plan because some editions have feature limitations and hardware support restrictions, while other editions are geared toward more specialized workloads.. The three main editions of SQL Server 2012 include Standard Edition, Business Intelligence Edition, and Enterprise Edition. SQL Server 2012 editions can be categorized as follows:

• Core Editions:
  • Enterprise
  • Business Intelligence
  • Standard
• Specialized Editions:
  • Developer
• Free Editions:
  • Express
  • Express LocalDB
  • Compact

The core editions of SQL Server 2012 are the three main editions that can be licensed for production, testing, Q.A., and U.A.T. environments.

The Developer Edition of SQL Server 2012 is a specialized license intended for development purposes only and cannot be used in production environments. The free editions of SQL Server 2012 are light-weight versions of SQL Server intended for learning, developing, and redistributing with small applications.

With each new release of SQL Server, new features are introduced and some existing features get shuffled around between editions. Understanding the available features for each edition is key in deploying the right edition that suits your needs.

In SQL Server 2012, additional features have been added to support highly scalable and highly available database environments as well as additional tools to support Enterprise Information Management. Some of these new features include the following:

• Column-store indexes
• Always-on Availability Groups
• Distributed Replay
• Data Quality Services
• Analysis Services xVelocity Engine (formerly known as Vertipaq)
• Windows Server Core Installation Support

Edition Differences

Several differences exist between SQL Server 2012 editions ranging from database size limitations to the number of supported processors and the maximum supported memory. Several features such as partitioning, encryption, compression, and some advanced indexing options are also a key difference between SQL Server 2012 editions.

• Enterprise Edition: SQL Server 2012 Enterprise Edition provides the highest level of scalability for large mission-critical application workloads. It provides support for the highest amount of memory and number of processors than any other edition to support an organization's entire consolidated and virtualized database infrastructure. Enterprise Edition includes several powerful tools for complex data analytics, large data warehouses, and end-to-end Business Intelligence solutions.
• Standard Edition: SQL Server 2012 Standard Edition is tailored for small to mid-sized organizations, capable of providing reliable data management and essential Business Intelligence capabilities.
• Parallel Data Warehouse: SQL Server 2012 Parallel Data Warehouse is a highly scalable appliance-based data warehouse solution. Parallel Data Warehouse provides cost-effective performance through a massively parallel processing (MPP) architecture that enables an organization to easily scale from terabytes of data to a petabyte range of data.
• Web Edition: SQL Server 2012 Web Edition is a cost-effective database solution to support web applications, websites, and web services. It is only available through hosting providers such as Amazon and Rackspace.
• Developer Edition: SQL Server 2012 Developer Edition includes all the functionality of Enterprise Edition for development, test, and demonstration purposes. It is not intended for production environments. You can purchase Developer Edition licenses for approximately $50. It is the most cost-effective way for developers to develop and test all the features available in SQL Server 2012.
• Evaluation Edition: SQL Server 2012 Evaluation Edition is a free 180-day trial license of SQL Server 2012 with all the functionality of Enterprise Edition. You can download the 180-day Evaluation Edition of SQL Server 2012 at www.microsoft.com/sqlserver/en/us/get-sql-server/try-it.aspx.
• Express Edition: SQL Server 2012 Express Edition is a free redistributable edition ideal for learning, managing, and developing small database applications. SQL Server 2012 Express Edition is limited to 10GB of storage per database.
• Express LocalDB Edition: SQL Server 2012 Express LocalDBEdition is a new, free, lightweight version of Express Edition that has a fast zero configuration installation and fewer prerequisites. It runs in user mode and includes all features found in Express Edition.
• Compact Edition: SQL Server 2012 Compact Edition is a free redistributable edition that can be embedded in mobile devices, desktops, and web clients.

Downgrading Later

A good SQL Server 2012 deployment plan eliminates the possibility of having to undo, redo, or make major changes to the configuration of a SQL Server installation. It some cases, you may be forced to change an existing installation to a different edition or version of SQL Server.

Downgrading Between SQL Server Editions

Suppose a new corporate IT licensing policy mandates that all middle-tiered database applications need to be SQL Server Standard Edition, in which case you may find yourself needing to downgrade an existing Enterprise Edition of SQL Server to the Standard Edition.

Downgrading from a higher-tier SQL Server 2012 edition to a lower-tier SQL Server edition, such as from the Enterprise Edition to the Standard Edition, is only possible by performing an uninstallation of SQL Server. The process requires you to install the lower-tier SQL Server edition after you uninstall the higher-tier SQL Server Edition.

You can re-attach or restore user databases from a database backup to the lower-tier SQL Server edition. User databases with higher-tier SQL Server edition specific features enabled cannot be attached or restored to a lower-tier SQL Server edition. For example, a database created in SQL Server 2012 Enterprise Edition that uses Enterprise Edition features, such as Table Partitioning or Transparent Data Encryption (TDE), cannot be restored or attached to the SQL Server 2012 Standard Edition without first disabling these edition-specific features.

To find out edition-specific features applied to a database, you can query the dynamic management view [sys].[dm_db_persisted_sku_features]. For example, the following T-SQL script queries edition-specific features applied to the SQL Server 2012 AdventureWorks2012 database:

SELECT [feature_name]
FROM [AdventureWorks2012].[sys].[dm_db_persisted_sku_features]

The [sys].[dm_db_persisted_sku_features] dynamic management view may return rows containing any of the following Enterprise or Developer Edition features:

• Compression
• Partitioning
• Transparent Data Encryption
• Change Capture

If no edition-specific features have been enabled in the user database, the [sys].[dm_db_persisted_sku_features] dynamic management view does not return any rows.

Downgrading Between SQL Server Versions

In some cases you may need to downgrade between a newer version of SQL Server back to a previous version. For example, a SQL Server version upgrade of an application's back-end database instance may have exposed bugs in the application that now force you to downgrade back to the previous SQL Server version.

You can downgrade from SQL Server 2012 to previous versions of SQL Server by following the same uninstallation process as previously mentioned. On the other hand, you can no longer attach or restore user databases created or attached to an older version of SQL Server to a SQL Server 2012 instance.

Setting the compatibility mode of a database attached to a SQL Server 2012 instance to a lower compatibility level does not mean you can attach or restore this database to an older version of SQL Server. The capability of setting a database at a lower compatibility level is provided for backward compatibility as a temporary step to support legacy code.

For example, a database attached to a SQL Server 2012 instance and set in compatibility mode level 90, enables you to run code compatible with SQL Server 2005, but you cannot restore this database to a SQL Server 2005 instance. Table 4 shows the database compatibility levels and corresponding SQL Server Version.

Table 4 SQL Server Database Compatibility Levels

SQL Server 2012 supports only databases at compatibility levels 90, 100, and 110, meaning it supports databases going back to SQL Server 2005 only.

To identify the compatibility level of a specific SQL Server database, you can query the master.sys.sysdatabases table as follows:

SELECT cmptlevel
FROM  master.sys.sysdatabases 
WHERE name='AdventureWorks2012'

All databases attached or restored to a newer version of a SQL Server instance upgrade automatically to the database version number that the newer SQL Server instance supports. In the case of SQL Server 2012, all databases created, attached, or restored in a SQL Server 2012 instance convert to database version number 700.

As you see, database compatibility levels are not the same as database version numbers. Perhaps Paul Randal described it best when he explained it this way: The database version number is an internal number associated with a specific structure of a database's system tables containing metadata about various objects such as tables, columns, indexes, allocations, and details about the relational and physical structure of the database.

Table 5 lists the database version number and the corresponding SQL Server version.

Table 5 SQL Server Database Version Numbers

To identify the version number of a specific SQL Server database, you can query the master.sys.sysdatabases table as follows

SELECT version
FROM  master.sys.sysdatabases 
WHERE name='AdventureWorks2012'

Upgrading Later

Selecting the right SQL Server Edition upfront allows you to accommodate for future needs as your business grows. Many organizations choose to deploy a SQL Server Edition that contains the features that meet the minimum requirements for their environment and upgrade to a different edition as additional features are needed.

Deploying the SQL Server 2012 edition that satisfies the minimum functionality requirements initially is a cost-effective way to manage licensing costs. You can upgrade all editions of SQL Server 2012 except for the Compact Edition to higher tier SQL Server editions. For example, you can upgrade Express, Web, and Workgroup editions to Standard, Enterprise, or Data Center editions. You can upgrade the Standard Edition to only the Enterprise or Data Center editions.

The upfront savings in licensing costs may justify the decision to install a lower or mid-tier SQL Server 2012 edition such as the Standard Edition. However, you also need to consider downstream effects on budget, time, and resources when the need to upgrade to a higher tier SQL Server Edition arises. Some of the factors that might require a higher tier SQL Server Edition upgrade include implementing more robust mechanisms for disaster recovery, high availability efforts, and scaling out as workloads increase.

For this reason, some organizations deploy higher tier SQL Server editions such as Enterprise, which allows them to scale up and scale out when necessary both for performance and availability purposes, without having to undergo an environment upgrade process.

Licensing Differences

The SQL Server 2012 release introduces significant changes to the licensing model than previous versions. The two licensing options, Server + CAL (Client Access License) and socket-based are still offered. The major differences revolve around the way processing power is licensed for the core-based licensing option and the licensing options available for each edition.

Core-Based Licensing

In previous releases of SQL Server, core-based licensing was based on the number of physical processors and was independent of the number of cores. With SQL Server 2012, each of the processor cores requires licensing. For example, to license a SQL Server 2008R2 Enterprise server with two quad-core processors, only two processor licenses were required, one for each physical processor. This type of licensing was referred to as per-socket licensing since it was based on the number of physical processors occupying a processor socket in the motherboard.

To license this same server running SQL Server 2012 Enterprise, licensing for eight cores is now required since each processor has four cores for a total of eight cores.

Core-based licenses are sold in two-core packs with a minimum of 4 core licenses required for each physical processor. This means that at a minimum you need to purchase two of these two-core packs for each physical processor occupying a processor socket. Table 6 provides the licensing matrix for different processor core configurations.

Table 6 Licensing Matrix for Different Processor Core Configurations

The number of two-core packs listed in the second column of Table 6, is the number of two-core packs required for each physical processor. As you may notice, even if you license a single or dual core processor, you still have to buy enough two-core packs to license the minimum of four cores. With this four-core minimum license per physical processor requirement of SQL Server 2012, it makes more sense to have a single four-core processor than two dual-core processors.

Server + CAL Licensing

Server + CAL Licensing for SQL Server 20120 is only available for the Standard and Business Intelligence Editions. Users need a CAL that is the same version or newer than the version of the licensed SQL Server they need to access. A SQL Server 2012 CAL can be used to access multiple licensed SQL Servers, including SQL Server 2012 Standard and Business Intelligence Editions. These new CALs can also be used for previous versions of SQL Server, including the Enterprise Editions of 2008 and 2008R2, for which the Server + CAL licensing model was still available.

Virtual Machine Licensing

Virtual machine licensing of SQL Server 2012 can be done in one of three ways: