The first version was initially called SEQUEL (Structured English Query Language) named SQL Server 1.0 for OS/2 in the year 1989 code name Microsoft SQL Server. Prior to version 7.0 the code base for MS SQL Server was sold by Sybase SQL Server to Microsoft, and it was a Microsoft's entry to the enterprise-level database market to competing against Oracle ,IBM and later Sybase itself.
There are at least a dozen different editions of Microsoft SQL Server is introduced. The last updated version 12.0 of SQL server was released by Microsoft in the year 2014 ,release name as sql Server 2014 as named sql14
The main objective of this language is to design ,store, manipulate and retrieve information from or through a database upto a huge amount.
The above architecture is divide into three major components they are:
- Relational Engine: Also called as the query processor, Relational Engine includes the components of SQL Server that determine what your query exactly needs to do and the best way to do it. It manages the execution of queries as it requests data from the storage engine and processes the results returned.
- Storage Engine: Storage Engine is responsible for storage and retrieval of the data on to the storage system (Disk, SAN etc.), like Data file and Log files.
- SQL OS: This lies between the host machine (Windows OS) and SQL Server. All the activities performed on database engine are taken care by SQL OS. It is a highly configurable operating system with powerful API (application programming interface),enabling automatic locality and advanced parallelism.
High Speed: SQL Queries can be used to retrieve large amounts of records from a database quickly and efficiently.
Well Defined Standards Exist: SQL databases use long-established standard,which is being adopted by ANSI & ISO. Non-SQL databases do not adhere to any clear standard.
No Coding Required: Using standard SQL it is easier to manage database systems without having to write substantial amount of code.
Emergence of ORDBMS: Previously SQL databases were synonymous with relational database. With the emergence of ObjectOriented DBMS, object storage capabilities are extended to relational databases.
Database is an important constituent for collection and storage of data. Data provided information after processing on them. To managing record and important data Databases server used. Database transaction is a unit of work in database management system. Database transaction must follow term ACID (Atomicity, Consistency, Isolation, Durability). Any transaction started then till it completion, that transaction follow ACID, for successful and no error.
Database define level of Abstraction
- Physical Level: Physical level is the lower level of abstraction. Its define how data is stored in database.
- Logical Level: The next higher level of abstraction, its describe what data be store and each logical operation done at this level, links and concept apply here.
- view Level: This is the higher level describe only part of entire database for a particular user.