Microsoft SQL Server 2008 R2 Unleashed- P9 docx

ptg 34 Running SQL Server 2008 inside a virtual operating environment requires at least one license per virtual operating environment. Within each virtual operating environment, the license allows you to run one or more instances of SQL Server 2008. The license for a virtual operating environment can be a server/CAL license or a processor-based license. If using a processor-based license, you must purchase a processor license for each processor that the virtual machine accesses. The total number of physical and virtual processors used by the virtual operating system environments cannot exceed the number of software licenses assigned to that server. However, if you are running Enterprise Edition and all physical processors in the machine have been licensed, you may run an unlimited number of virtual operating environments on that same machine. Multiple Instances of SQL Server An option to virtualization is multi-instancing. With multi-instancing, multiple copies of SQL Server can be run concurrently in a single instance of an OS. Multi-instancing for SQL Server 2008 can take place both in a virtual environment or in a physical environment. Although multi-instancing offers a relatively high degree of isolation between copies of SQL Server 2008, this isolation takes place at the application level (instead of at the OS level). In SQL Server 2008, the Workgroup and Standard Editions now allow you to run any number of instances of the server software in one physical or virtual operating system envi- ronment on the licensed server. Previously, only the Enterprise Edition of the server license allowed multi-instancing. Summary This chapter examined the various platforms that support SQL Server 2008 R2 and reviewed and compared the various editions of SQL Server 2008 that are available. Which platform and edition are appropriate to your needs depends on scalability, availability, performance, licensing costs, and limitations. The information provided in this chapter should help you make the appropriate choice. Chapter 2, “What’s New in SQL Server 2008,” takes at closer look at the new features and capabilities provided with the various SQL Server 2008 editions. CHAPTER 1 SQL Server 2008 Overview Download from www.wowebook.com ptg CHAPTER 2 What’s New in SQL Server 2008 IN THIS CHAPTER . New SQL Server 2008 Features . SQL Server 2008 Enhancements SQL Server 2005 provided a number of significant new features and enhancements over what was available in SQL Server 2000. This is not too surprising considering there was a five-year gap between these major releases. Microsoft SQL Server 2008 is not as much of a quantum leap forward from SQL Server 2005, but it provides a number of new features and enhancements to further extend the performance, relia- bility, availability, programmability, and ease of use of SQL Server. This chapter explores the new features provided in SQL Server 2008 and SQL Server 2008 R2, as well as many of the enhancements to previously available features. New SQL Server 2008 Features So what does SQL Server 2008 have to offer over SQL Server 2005? Following is an overview of the new features provided in SQL Server 2008: . New storage features—FILESTREAM storage, sparse columns and column sets, row-level and page-level data compression . New data types—Date, Time, and DATETIME2 data types; Hierarchyid data type; spatial data types; user- defined table type . New Transact-SQL (T-SQL) constructs—Compound operators, GROUPING SETS, MERGE statement, row constructors, table-valued parameters, INSERT over DML, new date and time functions . New performance features—Filtered indexes and statistics, FORCESEEK query hint, hash values for Download from www.wowebook.com ptg 36 CHAPTER 2 What’s New in SQL Server 2008 finding similar queries in the plan cache, Plan Guide Successful and Plan Guide Unsuccessful event classes, Guided/Misguided Plan Executions/sec Performance Monitor counters, LOCK ESCALATION option for ALTER TABLE, hot-add CPUs . New security features—Transparent data encryption, Extensible Key Management, SQL Server Audit . New database administration features—Backup compression, Change Data Capture, Change Tracking, the Data Collector, Policy-Based Management, SQL Server Extended Events, Resource Governor . New SQL Server management features—Transact-SQL Debugger, IntelliSense, error list window, multiserver queries, PowerShell integration SQL Server 2008 R2 further enhances SQL Server 2008 with the following new features: . Two new premium editions to meet the needs of large-scale datacenters and data warehouses: . SQL Server 2008 R2 Datacenter . SQL Server 2008 R2 Parallel Data Warehouse . SQL Server Utility for Multi-Server Management . PowerPivot for Excel and SharePoint . A number of new Reporting Services features including Report Builder 3.0, report parts, shared datasets, Sparklines and data bars, indicators, calculating aggregates of aggregates, maps, lookup functions The following sections take a closer look at each of these new features and, where appro- priate, provide references to subsequent chapters where you can find more information and detail about the new features. New Storage Features SQL Server 2008 provides a set of new features to reduce storage requirements and improve performance. One of the new features is FILESTREAM storage. FILESTREAM storage is a property that can be applied to varchar(max) columns; it enables SQL Server applications to store unstruc- tured data, such as documents and images, directly in the NTFS file system while still maintaining the behavior of a database column. The advantages of FILESTREAM storage are improved performance and increased size of BLOB data, expanding from the 2GB limit of image columns to the available space in the file system. For more information on using FILESTREAM storage, see Chapter 42, “What’s New for Transact-SQL in SQL Server 2008.” Other storage features introduced in SQL Server 2008 are sparse columns and column sets. Sparse columns are ordinary columns that have an optimized storage format for null values. If you use sparse columns, you can also define a column set on the table that will return all sparse columns in the table. A column set is an untyped XML representation that combines all the sparse columns of a table into a structured output. For more information Download from www.wowebook.com ptg 37 New SQL Server 2008 Features on defining sparse columns and column sets, see Chapter 24, “Creating and Managing Tables.” Row-level and page-level data compression also are introduced in SQL Server 2008. Data compression helps to reduce both storage and memory requirements as the data is compressed both on disk and when brought into the SQL Server data cache. Row-level compression isn’t true data compression but implements a more efficient storage format for fixed-length data. Page-level compression is true data compression, using both column prefix and dictionary-based compression. For more information on implementing data compression, see Chapter 24. New Data Types SQL Server 2008 introduces a handful of new data types. Two of the most welcome of these are the new DATE and TIME data types. These new data types allow you to store date- only and time-only values. In addition, SQL Server now supports the DATETIME2 and DATETIMEOFFSET data types. DATETIME2 is a variation of the DATETIME data type that supports datetime values from 0001-01-01 to 9999-12-31 23:59:59.999999. DATETIMEOFFSET supports UTC-based datetime values that are time zone aware. The new Hierarchyid data type is a common language runtime (CLR) user-defined type (UDT) that provides a mechanism for representing and storing a tree structure in a table in an efficient manner. This data type is useful for storing data that represents a parent child, tree-like structure such as an organizational structure or a graph of links between web pages. Spatial data types are introduced in SQL Server 2008 as well. There are two new spatial data types: geometry and geography. The geometry data type supports planar, or Euclidean (flat-earth), data. The geography data type stores ellipsoidal (round-earth) data, such as GPS latitude and longitude coordinates. These new data types support the storage and manipulation of spatial data objects such as linestrings, points, and polygons. SQL Server 2008 also introduces a new user-defined table type that can be used as parame- ters in stored procedures and functions, as well as for defining table variables in a batch or the body of a stored procedure or function. For more information and examples on using the new SQL Server 2008 data types, see Chapter 42. New Transact-SQL Constructs What would a new SQL Server release be without new T-SQL commands and constructs to further expand the power and capabilities of the T-SQL language? SQL Server 2008 is no exception (although SQL Server 2008 R2 is an exception because no new T-SQL constructs are introduced in R2). The new constructs provided in SQL Server 2008 include . Compound operators—New operators that provide a shorthand method of performing an operation and assigning a value to a local variable (for example, +=, *=). 2 Download from www.wowebook.com ptg 38 CHAPTER 2 What’s New in SQL Server 2008 . GROUPING SETS—New operator added to the GROUP BY clause to perform multiple grouping operations in a single query. . MERGE statement—New DML statement that can perform INSERT, UPDATE, or DELETE operations on a target table based on the results of a join with a source table. . Row constructors—An enhancement to the VALUES clause that allows multiple row inserts within a single INSERT statement. Also provides the ability to use the VALUES clause to create a pseudo table of values in a subquery or common table expression. . Table-valued parameters—New parameter type that can be assigned the new user- defined table types. Table-valued parameters enable you to pass a table variable con- taining multiple rows of data to a stored procedure or function without the need to create a temporary table. To coincide with the new DATE and TIME data types, SQL Server 2008 also introduces a few new date and time functions: . SYSDATETIME()—Returns the current system datetime as a DATETIME2(7) value . SYSDATETIMEOFFSET()—Returns the current system datetime as a DATETIMEOFFSET(7) value . SYSUTCDATETIME—Returns the current system datetime as a DATETIME2(7) value representing the current UTC time . SWITCHOFFSET (DATETIMEOFFSET, time_zone)—Changes the DATETIMEOFFSET value from the stored time zone offset to the specified time zone . TODATETIMEOFFSET (datetime, time_zone)—Converts a local datetime value for the specified time zone to a DATETIMEOFFSET UTC value For more information and examples on using the new SQL Server 2008 T-SQL constructs, see Chapter 42. New Performance Features SQL Server 2008 also introduces some new features and enhancements for monitoring, managing, and improving query performance. Among these new features are filtered indexes and statistics. A filtered index is a nonclustered index defined on a subset of data using a filter predicate to index only a portion of rows in the table. Filtered statistics are statistics defined on a subset of data in the table using a filter predicate. A well-designed filtered index can improve query performance, reduce index maintenance costs, and reduce index storage costs compared with full-table indexes, especially when columns contain a large number of rows with null or a single value that isn’t searched on but can skew the index and statistics. For more information on creating and using filtered indexes and statistics, see Chapter 34, “Data Structures, Indexes, and Performance.” SQL Server 2008 provides FORCESEEK as a new table and query hint for controlling how SQL Server optimizes a query; it forces the optimizer to use only an index seek operation to access the data in the referenced table or view. For more information on using the FORCESEEK hint, see Chapter 35, “Understanding Query Optimization.” Download from www.wowebook.com ptg 39 New SQL Server 2008 Features Plan guides were a feature introduced in SQL Server 2005. Plan guides can be used to opti- mize the performance of queries when you cannot or do not want to change the text of the query directly (for example, when queries in a third-party database application are not performing as expected). SQL Server 2008 provides additional features related to plan guides to make implementing and managing them easier. Among these features are new event classes (Plan Guide Successful and Plan Guide Unsuccessful) that can be monitored via SQL Server Profiler to determine when plan guides are being applied. There are also two new Performance Monitor counters (Guided/Misguided Plan Executions/sec) that you can use to monitor via Performance Monitor how often plan guides are being used or not being used. SQL Server 2008 also now generates hash values for query plans in the plan cache. The sys.dm_exec_query_stats and sys.dm_exec_requests dynamic management views (DMVs) now provide query hash and query plan hash values that you can use to help find similar queries in the plan cache. Locating similar queries can help you determine the aggregate resource usage for similar queries and similar query execution plans so that you can better focus your query tuning efforts and help identify which queries may get the most benefit from using plan guides. For more information on query plans and using plan guides, see Chapter 35. To provide greater control of locking, SQL Server 2008 offers the new LOCK ESCALATION table option. This option specifies the allowed methods of lock escalation for a table. The default is AUTO, which allows the Database Engine to select the appropriate lock escalation level for the query if a table is partitioned. You can also specify TABLE to force full table- level locking whether or not a table is partitioned. A third option, DISABLE, prevents esca- lation to a table-level lock in most cases. For more details on locking and the LOCK ESCALATION option, see Chapter 37, “Locking and Performance.” One additional new feature in SQL Server 2008 Enterprise Edition is hot-add CPU. Hot-add CPU is the capability to dynamically add CPUs to a running system. Additional CPUs can be made available logically by online hardware partitioning, virtually through a virtualiza- tion layer, or even physically by adding new hardware on systems that support adding physical CPUs while the system is online. Hot-add CPU, which requires hardware support, is available only when you’re running Windows Server 2008 Datacenter or Enterprise Edition. New Security Features SQL Server 2005 provided the capability to encrypt data at the column level. However, this encryption was not transparent to the end users or applications. Encrypting and decrypting the data required coding changes to use the built-in encryption and decryption functions. SQL Server 2008 introduces transparent data encryption (TDE), which allows for encrypting the entire database without affecting client applications. The purpose of TDE is to protect sensitive data in the event a database file or backup is stolen. Encryption is done in real-time at the page level as the data is written to disk and decrypted as the data is read from disk. The encryption is based on a database encryption key (DEK), which is a symmetric key secured by using a certificate stored in the master database of the server or an asymmetric key protected by an Extensible Key Management (EKM) module. 2 Download from www.wowebook.com ptg 40 CHAPTER 2 What’s New in SQL Server 2008 Extensible Key Management, which is also new with SQL Server 2008, enables you to store the keys used to encrypt data separately from the data it protects. SQL Server 2008 EKM enables the encryption keys that protect the database files to be stored in a removable device such as a smartcard, USB device, or a software-based Extensible Key Management (EKM)/Hardware Security Module (HSM) module. EKM facilitates separation of duties by taking key management out of the hands of the database administrators. For more information on implementing and using transparent data encryption and exten- sible key management, see Chapter 12, “Data Encryption.” SQL Server already provides a number of existing audit methods (SQL Trace, C2 audit mode, DDL triggers). In addition to these, SQL Server 2008 adds an additional audit method: SQL Server Audit. SQL Server Audit, based on the new Extended Events feature, allows you to monitor server- or database-level events or groups of events. You can set up and monitor audit events at the server or database level and audit the audit actions them- selves. For more information on SQL Server Audit, see Chapter 13, “Security and Compliance.” New Database Administration Features SQL Server 2008 introduced backup compression for Enterprise Edition. With SQL Server 2008 R2, backup compression is supported in Standard and all higher editions (every edition of SQL Server 2008 and later can restore a compressed backup, however). In addi- tion to the space savings provided by compressed backups, compressing a backup also typically increases backup speed because it requires less device I/O. However, the I/O cost savings comes at the expense of increased CPU usage caused by the compression process. For more information on compressing backups, see Chapter 14, “Database Backup and Restore.” Policy-Based Management is a new mechanism in SQL Server 2008 for managing one or more instances of SQL Server 2008. SQL Server Policy-Based Management can help to simplify management operations such as setting database options across multiple servers, checking SQL Server configurations, or enforcing naming conventions, helping to reduce the total cost of ownership (TCO) of administering multiple SQL Server instances. SQL Server Management Studio (SSMS) can be used to define and implement policies for managing SQL Server instances, databases, or other SQL Server objects as well as on- demand checking and enforcement of policies. Checking and enforcement of these poli- cies can also be scheduled using SQL Server Agent. For more information on Policy-Based Management in SQL Server, see Chapter 22, “Administering Policy Based Management.” Currently, several options are available for troubleshooting or getting information about SQL Server–generated events: SQL Server Profiler, SQL Server Log, dynamic management views and functions, SQL Trace, trace flags, Windows Application and System logs, perfor- mance counters, and so on. SQL Server 2008 introduces a new event infrastructure, Extended Events. Extended Events is a general-purpose event-handling system for server systems. Currently, the Extended Events infrastructure supports the correlation of data from SQL Server and, under certain conditions, the correlation of data from the operating system and database applications. Extended Events has the potential to make other trou- Download from www.wowebook.com ptg 41 New SQL Server 2008 Features bleshooting options obsolete in future releases and become the common denominator for troubleshooting purposes. As mentioned previously, the new SQL Server Audit feature is based on Extended Events. For more information on configuring and using Extended Events for monitoring SQL Server 2008, see Chapter 39, “Monitoring SQL Server Performance.” Resource Governor, another new technology in SQL Server 2008, enables you to manage and control the allocation of resources for SQL Server according to workload. Similarly sized queries or requests that can, and should be, treated the same are assigned to a work- load group as the requests are received. Each workload group is associated to a pool of resources that represents the physical resources for SQL Server (currently, for SQL Server 2008, these resources are CPU and memory). Limits are specified on resource consumption for these incoming requests. In an environment where multiple distinct workloads are present on the same server, Resource Governor enables you to differentiate these work- loads and allocate shared resources as they are requested, based on the limits you specify. For more information on implementing and configuring Resource Governor, see Chapter 40, “Managing Workloads with the Resource Governor.” Change Data Capture (CDC) and Change Tracking are new features in SQL Server 2008 with similar names but different purposes. CDC is an asynchronous mechanism that captures all changes of a data row from the transaction log and stores them in change tables. The information captured is available in relational format and can be accessed by client applications such as extract, transform, and load (ETL) processes. All intermediate values of a row are stored. Using Change Data Capture, you can avoid using expensive techniques such as triggers, time stamp columns, and join queries to identify and capture the changes made to data. Change Tracking, on the other hand, is a lightweight synchronous mechanism that tracks data modifications but records only the fact that a row has changed. Applications can use Change Tracking to identify which rows have changed for a user table and refresh their data stores with the latest values from these rows by requerying the table. For more information on using CDC and Change Tracking, see Chapter 42. New SQL Server Management Studio Features SQL Server Management Studio (SSMS) was first introduced in SQL Server 2005. SSMS is a full-featured, robust SQL Server administration and development tool. However, there was clearly room for improvement, and SQL Server 2008 provides some long-awaited enhance- ments. One of the most anticipated (and missed) features in SSMS was a built-in T-SQL debugger. Prior to SQL Server 2005, SQL Server Enterprise Manager had a built-in T-SQL Debugger. A lot of users were disappointed a T-SQL debugger was not included with this version of SSMS. To debug T-SQL, you needed to install Visual Studio (VS). Fortunately, a built-in debugger returns to SSMS in SQL Server 2008. Another long-awaited feature for SSMS is IntelliSense. IntelliSense is a useful feature in the Query Editor for looking up language elements and object names without having to leave 2 Download from www.wowebook.com ptg 42 CHAPTER 2 What’s New in SQL Server 2008 the editor. IntelliSense can even automatically complete and insert language elements directly into your code. In conjunction with IntelliSense, SSMS also provides the error list window The error list window displays all errors and warnings produced by IntelliSense as you develop your code in the Database Engine Query Editor. You can double-click the error message entry to jump to the error location. As you fix errors, they are automatically removed from the error list window. One other new capability built in to SSMS in SQL Server 2008 is multiserver queries. This feature allows you to execute T-SQL statements against multiple servers defined in a server group at the same time. If you open a Query Editor from the server group in the Registered Servers window, the T-SQL statements in the current Query Editor are executed against all the servers in the group. The results from the query can be merged into a single results pane or can be returned in separate results panes for each server. For more details on these new features in SSMS, see Chapter 4, “SQL Server Management Studio.” PowerShell Integration SQL Server 2008 provides integrated support for Windows PowerShell, a powerful scripting shell that enables administrators and developers to automate server administration and application deployment. The Windows PowerShell language supports more complex logic than Transact-SQL scripts, enabling SQL Server administrators to build more robust and complex administration scripts. SQL Server provides two snap-ins to Windows PowerShell for creating scripts to manage SQL Server: . A SQL Server provider, which enables a simple navigation mechanism similar to file system paths where the drive is associated with a SQL Server management object model and the nodes are based on the object model classes. This allows you to use familiar commands such as cd and dir to navigate the paths similar to the way you navigate folders in a command prompt window. . A set of cmdlets, which are commands used in Windows PowerShell scripts to speci- fy a SQL Server action, such as running a SQLCMD script containing Transact-SQL or XQuery statements For more information on managing SQL Server using PowerShell, see Chapter 17, “Administering SQL Server 2008 with PowerShell.” New Premium SQL Server Editions SQL Server 2008 R2 introduces two new premium-level editions of SQL Server: Datacenter Edition and Parallel Data Warehouse. Built on SQL Server 2008 R2 Enterprise, SQL Server 2008 R2 Datacenter is designed to deliver a high-performing data platform that provides the highest levels of scalability for large application workloads, virtualization and consolidation, and management for an Download from www.wowebook.com ptg 43 New SQL Server 2008 Features organization’s database infrastructure. Datacenter helps enable organizations to cost-effec- tively scale their mission-critical environment. Key features of Datacenter include . Application and multiserver management for enrolling, gaining insights, and managing more than 25 instances . Highest virtualization support for maximum return on investment (ROI) on consoli- dation and virtualization . High-scale complex event processing with SQL Server StreamInsight . Support for more than 8 processors and up to 256 logical processors SQL Server 2008 R2 Parallel Data Warehouse is a highly scalable data warehouse appliance- based solution. Parallel Data Warehouse delivers performance at low cost through a massively parallel processing (MPP) architecture and compatibility with hardware partners, allowing you to scale your data warehouse to tens and even hundreds of terabytes. Key features provided by Parallel Data Warehouse include . Advanced data warehousing capabilities such as Star Join Queries and Change Data Capture . Integration with SSIS, SSRS, and SSAS . Support for industry-standard data warehousing hub-and-spoke architecture and par- allel database copy SQL Server Utility for Multiserver Management SQL Server 2008 R2 features new SSMS dashboards for observing information on more than one server from the same screen by utilizing the new SQL Server Utility. The SQL Server Utility models an organization’s SQL Server–related entities in a unified view. Utility Explorer and SQL Server Utility viewpoints in SQL Server Management Studio provide administrators a holistic view of SQL Server resource health. Entities that can be viewed in the SQL Server Utility include . Instances of SQL Server . Data-tier applications . Database files . Volumes SQL Server Utility is covered in more detail in Chapters 4 and 39. PowerPivot for Excel and SharePoint PowerPivot is a new tool that integrates SQL Server with Microsoft Excel and SharePoint to create a self-service business intelligence (BI) solution for the enterprise. PowerPivot for Excel and SharePoint are client and server components that integrate Analysis Services with Excel and SharePoint. PowerPivot for Excel is an add-in that allows you to create PowerPivot workbooks that can assemble and relate large amounts of data from different 2 Download from www.wowebook.com . SQL Server 2008 and SQL Server 2008 R2, as well as many of the enhancements to previously available features. New SQL Server 2008 Features So what does SQL Server 2008 have to offer over SQL. T -SQL language? SQL Server 2008 is no exception (although SQL Server 2008 R2 is an exception because no new T -SQL constructs are introduced in R2) . The new constructs provided in SQL Server 2008. Governor . New SQL Server management features—Transact -SQL Debugger, IntelliSense, error list window, multiserver queries, PowerShell integration SQL Server 2008 R2 further enhances SQL Server 2008 with