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SQL SPECIFIC FEATURES TUTORIALS

1)     Vendors Independence: SQL is offered by all of the leading DBMS vendors. A SQL based database that use it can be moved from one to another vendor’s DBMS with minimal conversion effort. PC database tools such as query tools, report writers and application generators work with many different brands of SQL.

2)     Portability across computer system: SQL based database products runs on computer systems ranging from mainframes and midrange systems to personal computers, workstations & even handheld devices. SQL based applications that begin on single user systems can be moved to large servers systems as they grow.

3)     SQL standards: An official standard for SQL was initially published by ANSI & ISO in 1986, and was expanded in 1989 and again 1992; SQL is also a U.S Federal Information Processing Standards (FIPS), making it a key requirement for large government computer contracts.

4)     IBM Endorsement (DB2): SQL was originally invented by IBM researchers and has since become a strategic product for IBM based on its flagship DB2 database. SQL support is available on all major IBM product families, from personal computer to midrange system to IBM Mainframe.

5)     Microsoft commitment (ODBC & AOD): Both & desktop & server version of windows provides standardized relational database access through Open DataBase Connectivity (ODBC), a SQL based call level XPI. Microsoft has enhanced ODBC support with higher level, more database access layers as a part of its Object Linking and Embedding technology (OLEDB) & more recently as a part of Active/X Data Object (ADO).

6)     Relational Foundation: SQL is a language for a relational databases & it has become popular with relational database model. The relational model has a strong theoretical foundation that has guided the evolution and implementation of relational database.

7)     High-Level, English like structure: SQL statement looks like simple English sentence, making SQL easy to learn & understand most SQL statement “ say what they mean” & can be read as clear natural sentences.

8)     Interactive ad-hoc queries: SQL is an interactive query language that gives users ad hoc access to stored data. Using SQL interactively, a user can get answers even to complex questions in minutes or seconds. Because of SQL ad hoc query power data is more accessible and can be used to make an organization better & more informed decision.

9)     Programmatic Database access: SQL is also database language used by programmers to write application that access a database. The same SQL statements are used for both interactive & programmatic access.

10)  Multiple views of data: Using SQL, the creator of the database, can give different users of the database, different views of its structure and content. Also, data from several different part of the database can be combined presented to the user as simple row/column table.

11)  Complete database language: SQL was first developed as an ad hoc query language SQL provides a complete consistent language for creating the database, managing its security, updating its contents, retrieving data & sharing data among many concurrent users. SQL concept that is learnt in our part of the language can be applied to other SQL commands.

12)  Dynamic Data Definition: Using SQL, the structure of database, can be changed & expanded dynamically. This is a major advance over static data definition language, which prevented access to the database while its structure was leaving changed. SQL thus provides maximum flexibility, allowing a database to adapt to changing requirements which online application continue uninterrupted.

13)  Client/Server Architecture: SQL as a link between front-end computer systems optimized for user interaction & back-end computer system specialized for database management. SQL also allows personal computers to function as front-end to network servers.

14)  Extensibility & Object technology: There is an introduction of object based programming and object based databases. SQL based database vendors has slowly expanded and enhanced SQL to include object features. Thus there are object/relational database.

15)  Internet database access: SQL found a new role in late 1990s as an internet data access center. Earlier, develops needed a way to retrieve and present database information on the web pages, but more recently, the introduction of three-tier internet architecture with distinct thin client, application server and database server layers, have established SQL as the standard link between application and database tiers.

16)  Java Integration (JDBC): Seeing the need to link java language to existing relational databases, sun micro systems introduced java database connectivity (JDBC), a standard XPI that allows java programs to use SQL for database access.

17)Many of the leading database vendors have also implemented java support, with in the database system, allows java to be used as a language for store procedures and business logic with the database itself.

 

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