Symmetric multiprocessor architecture MS SQL Server provides use of Windows operating system services for management of threads, memory, operations of disk reading/record, network services, security functions, and also for support of parallel performance of streams on several CPU.

Use of Windows threads allows MS SQL Server automatically to be scaled at work on multiprocessing platforms that excludes necessity of an additional configuration or program adjustment. Unlike the majority widespread DB, compelled to incorporate mechanisms of operating system kernel duplication for maintenance cross-country-platform of bearableness, MS SQL Server possesses enough superficial transparent architecture, not havy functions unusual for it. As a result, for example, at change of the processor type it is not required to get anew MS SQL Server for a new hardware platform. It is put, by definition, on everything on what works Windows (for today it Intel, Alpha, MIPS and PowerPC).

As Windows Server wins the increasing recognition and all leading manufacturers DB already have let out versions of the products under this operating system or have already declared it the readiness to make in the near future, primary orientation on MS SQL Server on close integration with Windows 2003 Server represents itself as one of serious advantages.

The separate working thread is appointed to each user connection in MS SQL Server (the order 55Kb) within the limits of uniform server process. As each of these streams actually is stream Win32, on them corresponding functions of the operating system control, including protection of memory, a rule of access to the equipment and planning of thread scheduling extend. It gives the improved abilities to scaling at growth of number of simultaneously working users, dynamic balancing at loading processors and raised reliability. In fact the user inquiries executed on different streams, are protected from each other.

Notwithstanding what the pool of connections is limited by 1024 streams, dynamic management of the user connections and free streams allows to increase this size up to 32 767. Besides other pools of streams can be used for parallel performance of data scanning operations, removal and updating, reserve copying, check of base integrity, indexing, asynchronous advancing data reading in a cache on the basis of a prediction algorithms, creation and management of cursors, etc.

Network services Windows provide MS SQL Server support of protocols TCP/IP, NWLink IPX/SPX, Named Pipes (NetBEUI), Banyan Vines, AppleTalk (ADSP) and DECNet. In version 7.0 to them the additional network library - multiprotocol network library which "is able to listen" to ports TCP/IP, SPX sockets or named pipes which usually get out dynamically was added. Doubtless advantage multiprotocol is presence of the network service providing interaction between processes by means of removed procedures call that allows to use, for example, enciphering at data transmission.

The multiline kernel and integration with services of planning of threads Windows 2003 Server provides high efficiency MS SQL Server at processing OLTP-and DSS-inquiries that is especially appreciable at simultaneous work of several hundreds users.

In the published results on testing MS SQL Server for the maximal number of simultaneously working users figure 7000 though really working applications where loading reached 10000 simultaneous user connections are known is resulted.

7,5 thousand transactions a minute means rate, that one MS SQL Server is capable 24õ7 to serve at an operating mode the little less than 11 million transactions day. There is one more parameter closely connected with productivity which, not being in strict sense of a word technical, is very popular in the West at an estimation of opportunities of this or that databases server as on it essentially depends cost of product ownership. It is a question of the specific price for transaction in a minute, otherwise, how many it is necessary to pay for achievement of inquiry processing such speed.

MS SQL Server includes Web-assistant - the program-master for preparation of the publication on Web-pages of data from base, SQL Mail - the utility providing integration with e-mail MS Mail or MS Exchange, MS Distributed Transaction Coordinator (MS DTC) for carrying out of the distributed transactions and some other means. SQL Server, MS DTC and SQL Executive function as services of operating system. The coordinated work of these components is reached owing to three-level architecture SQL-DMF (Distributed Management Frame-work).

The distributed environment of management allows to simplify considerably processes of the centralized control over many servers which can be united in groups for safety reasons or with the administrative purposes, and their objects to which concern:

• Devices on which databases physically settle down;
• The reserve devices containing safety copies of databases and objects inside of it;
• Databases:
• Users and groups of users;
• Tables;
• Representations;
• Saved procedures;
• Rules;
• Restrictions of type default;
• The types of data certain by the user;
• Logins for connection with a server.