Microsoft SQL

Microsoft SQL server is a relational database management system.It is developed by Microsoft.It is a software product with the primary function of storing and retrieving data as a database server.those software applications run on same computer or on another computer across a network.

This program has written on C and C++ languages.Operating Systems that are run this,Linux,Microsoft Windows Server and Microsoft Windows.This software is available in many languages.License are in as a proprietary software.

History of the MSSQL

Ashton-Tate and Sybase were Joined Microsoft to create a variant of Sybase SQL Server in 1988.It was the first version of the Microsoft SQL and the entry of the database market.It was competing against the oracle,IBM,Inform-ix,Ingres and Sybase.In 1993 Sybase ND Microsoft parted ways and each pursued its own designs.miscrosoft SQL 7.0 wasa major rewrite of the older Sybase.It was coded in C.After fe years User Mode Sheduling was introduced to handle the SQL.It was better than the Windows Preemptive multi threading. and also,it was included a multi dimensional database product.It was called as SQL OLAP service.It was the last version to run on the DEC Alpha platform.

Architecture of the MSSQL

The protocol layer implements the external interface to SQL server.All operations can be invoked from communicating to it via Microsoft defined format.It is called as Tabular Data stream(TDS).TDS is a application layer protocol.It is used to transfer data between the database server and the client.TDS packet can be encased in other transport protocols also.Those are TCP/IP.named pipes and shared memory.

Data storage is a database and it has collection of tables with typed columns.The sever of SQL is supported different data types such as integer,float,decimal,character,binary.And also it allows user-defined composite types to be defined and  used.And also tables, a database can contain other objects such as views,stored procedures,indexes and contains.SQL data base can contain maximum of 2 to the power 31 objects and maximum of 2 to the power 60 files.

the storage space has allocated  to a database is divided into sequentially numbered pages each 8kb in size. Page type define the data contain in the page.Page is the basic unit of an I/O operation,space is actually manage in terms of an extent which consists of 8 pages.The data in columns can be moved to a new page and can replace with a pointer to the data.


Buffer management

SQL server buffers pages in RAM to minimize disk I/O.Any 8KB page can be buffered to the memory.It is called as buffer cache.The buffer cache is managed by the buffer manager.The page is updated on the disk by the buffer manager.

Concurrency and locking

SQL server allows to multiple clients to use the same database concurrency.It need to control concurrent access to shared data.SQL server provides two modes of concurrency control.

• Pessimistic concurrency

         Pessimistic concurrency is used SQL server controls concurrent access by using locks.

• Optimistic concurrency

                Optimistic concurrency is a control mechanism,it is similar to the multi version concurrency control used in databases.

Services of the MSSQL

• Machine Learning Services
• Service Blocker
• Replication Services

            Transaction replication

             Merge replication

             Snapshot replication

• Analysis Services
• Reporting services
• Notification Services
• Integration Services  
• Full text search Services
• SQLCMD
• Visual Studio
• SQL server management studio
• SQL server operation studio
• Business intelligence Development Studio

Interfaces of MSSQL