Microsot SQL Server

Microsoft SQL Server is a relational model database server produced by Microsoft. Its primary query languages are T-SQL and ANSI SQL. The current version of SQL Server, SQL Server 2008 was released (RTM) on August 6, 2008 and aims to make data management self-tuning, self organizing, and self maintaining with the development of SQL Server Always On technologies, to provide near-zero downtime. SQL Server 2008 will also include support for structured and semi-structured data, including digital media formats for pictures, audio, video and other multimedia data. In current versions, such multimedia data can be stored as BLOBs (binary large objects), but they are generic bitstreams. Intrinsic awareness of multimedia data will allow specialized functions to be performed on them.

Other new data types include specialized date and time types and a Spatial data type for location-dependent data. Better support for unstructured and semi-structured data is provided using the new FILESTREAM data type, which can be used to reference any file stored on the file system. Structured data and metadata about the file is stored in SQL Server database, whereas the unstructured component is stored in the file system. Such files can be accessed both via Win32 file handling APIs as well as via SQL Server using T-SQL; doing the latter accesses the file data as a BLOB. Backing up and restoring the database backs up or restores the referenced files as well. SQL Server 2008 also natively supports hierarchical data, and includes T-SQL constructs to directly deal with them, without using recursive queries.

Microsoft makes SQL Server available in multiple editions, with different feature sets and targeting different users. These editions are

SQL Server Compact Edition (SQL CE)
The compact edition is an embedded database engine. Unlike the other editions of SQL Server, the SQL CE engine is based on SQL Mobile (initially designed for use with hand-held devices) and does not share the same binaries. Due to its small size (1MB DLL footprint), it has a markedly reduced feature set compared to the other editions. For example, it supports a subset of the standard data types, does not support stored procedures or Views or multiple-statement batches (among other limitations). It is limited to 4GB maximum database size and cannot be run as a Windows service, Compact Edition must be hosted by the application using it. The 3.5 version includes considerable work that supports ADO.NET Synchronization Services.

SQL Server Developer Edition
SQL Server Developer Edition includes the same features as SQL Server Enterprise Edition, but is limited by the license to be only used as a development and test system, and not as production server.

SQL Server Express Edition
SQL Server Express Edition is a scaled down, free edition of SQL Server, which includes the core database engine. While there are no limitations on the number of databases or users supported, it is limited to using one processor, 1 GB memory and 4 GB database files. The entire database is stored in a single .mdf file, and thus making it suitable for XCOPY deployment. It is intended as a replacement for MSDE.

SQL Server Standard Edition
SQL Server Standard edition includes the core database engine, along with the stand-alone services. It differs from Enterprise edition in that it supports fewer active instances (number of nodes in a cluster) and does not include some high-availability functions such as hot-add memory (allowing memory to be added while the server is still running), and parallel indexes.

The main unit of data storage is a database, which is a collection of tables with typed columns. SQL Server supports different data types, including primary types such as Integer, Float, Decimal, Char (including character strings), Varchar (variable length character strings), binary (for unstructured blobs of data), Text (for textual data) among others. It also allows user-defined composite types (UDTs) to be defined and used.

The data in the database are stored in primary data files with an extension .mdf. Secondary data files, identified with an .ndf extension, are used to store optional metadata. Log files are identified with the .ldf extension. Storage space allocated to a database is divided into sequentially numbered pages, each 8 KB in size. A page is the basic unit of I/O for SQL Server operations. A row in a database table cannot span more than one page, so is limited to 8 KB in size. However, if the data exceeds 8 KB and the row contains Varchar or Varbinary data, the data in those columns are moved to a new page (or possibly a sequence of pages, called an Allocation unit) and replaced with a pointer to the data. SQL Server buffers pages in RAM to minimize disc I/O. Any 8 KB page can be buffered in-memory, and the set of all pages currently buffered is called the buffer cache. The amount of memory available to SQL Server decides how many pages will be cached in memory. The buffer cache is managed by the Buffer Manager. Either reading from or writing to any page copies it to the buffer cache. Subsequent reads or writes are redirected to the in-memory copy, rather than the on-disc version.

Microsoft SQL Server 2005 includes a component named SQL CLR ("Common Language Runtime") via which it integrates with .NET Framework. Unlike most other applications that use .NET Framework, SQL Server itself hosts the .NET Framework runtime, i.e., memory, threading and resource management requirements of .NET Framework are satisfied by SQLOS itself, rather than the underlying Windows operating system. SQLOS provides deadlock detection and resolution services for .NET code as well. With SQL CLR, stored procedures and triggers can be written in any managed .NET language, including C# and VB.NET. Managed code can also be used to define UDT's (user defined types), which can persist in the database. Managed code is compiled to .NET assemblies and after being verified for type safety, registered at the database.

SQL Server Analysis Services adds OLAP and data mining capabilities for SQL Server databases. The OLAP engine supports MOLAP, ROLAP and HOLAP storage modes for data. Analysis Services supports the XML for Analysis standard as the underlying communication protocol.

SQL Server Reporting Services is a report generation environment for data gathered from SQL Server databases. It is administered via a web interface. Reporting services features a web services interface to support the development of custom reporting applications. Reports are created as RDL files.

SQL Server Integration Services is used to integrate data from different data sources. It is used for the ETL capabilities for SQL Server for data warehousing needs. Integration Services includes GUI tools to build data extraction workflows integration various functionality such as extracting data from various sources, querying data, transforming data including aggregating, duplication and merging data, and then loading the transformed data onto other sources, or sending e-mails detailing the status of the operation as defined by the user.

SQL Server Management Studio is a GUI tool included with SQL Server 2005 and later for configuring, managing, and administering all components within Microsoft SQL Server. The tool includes both script editors and graphical tools that work with objects and features of the server. SQL Server Management Studio replaces Enterprise Manager as the primary management interface for Microsoft SQL Server since SQL Server 2005. A version of SQL Server Management Studio is also available for SQL Server Express Edition, for which it is known as SQL Server Management Studio Express (SSMSE).

Business Intelligence Development Studio (BIDS) is the IDE from Microsoft used for developing data analysis and Business Intelligence solutions utilizing the Microsoft SQL Server Analysis Services, Reporting Services and Integration Services. It is based on the Microsoft Visual Studio development environment but customizes with the SQL Server services-specific extensions and project types, including tools, controls and projects for reports (using Reporting Services), Cubes and data mining structures (using Analysis Services).

Language Integrated Query (LINQ) is a .NET Framework version 3.5 feature that provides developers with a common syntax to query any data source from client applications. Using LINQ to SQL or LINQ to Entities, developers can select, insert, update, and delete data that is stored in SQL Server 2008 databases using any .NET programming language such as C# and VB.NET.

Common Language Runtime functionality in SQL Server 2008 has been improved in several areas. User-defined aggregates (UDAs) now support up to 2GB of data and can accept multiple inputs. User-defined types (UDTs) are, like UDAs, and also support up to 2GB of data. CLR table-valued functions now feature an optional ORDER clause in the CREATE FUNCTION statement, which helps the optimizer to run the query more efficiently.

SQL Server 2008 introduces several new date and time based data types. DATETIME2 references the Coordinated Universal Time (UTC) instead of the system time for greater accuracy and can store date and time data to a precision of 100 nanoseconds. The new DATE and TIME data types enable you to store date and time data separately. The new DATETIMEOFFSET data type introduces time zone support by storing date, time and offset such as 'plus 5 hours'.

FILESTREAM enables binary large object (BLOB) data to be stored in the Microsoft Windows NTFS file system instead of in a database file. Data that is stored using FILESTREAM behaves like any other data type and can be manipulated using T-SQL select, insert, update and delete statements.

SQL Server 2008 delivers on Microsoft's Data Platform vision by helping the organization manage any data, any place, any time. Store data from structured, semi-structured, and unstructured documents, such as images and rich media, directly within the database. SQL Server 2008 delivers a rich set of integrated services that enable us to do more with your data such as query, search, synchronize, report, and analyze.

SQL Server 2008 provides the highest levels of security, reliability, and scalability for our business-critical applications. To take advantage of new opportunities in today's fast-moving business world, companies need the ability to create and deploy data-driven solutions quickly. SQL Server 2008 reduces time and cost of management and development of applications.

Try SQL Server 2008 from the below links

SQL Server Developer Center is another best place to get more information about SQL Server 2008. This has details for the best practices and technical details about virtualizing SQL Server. The MSDN link for the SQL Server is here

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