Rajini’s Enthiran latest stills

 

shriya saran in white dress look sensuous

shriya saran in white dress look sensuous

Meera Chopra southindian actress hOt show

Meera Chopra telugu actress hot pic gallery

sridevi yesteryear ever green actress

sridevi yesteryear ever green actress

sridevi yesteryear ever green actress still look young.

Nayanthara’s Pothys Designer Sarees pictures

Nayanthara’s Pothys Designer Sarees pictures

;

Relational Database - Codd's Rules

Relational Database - Codd's Rules !!!

A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. Most popular commercial and open source databases currently in use are based on the relational database model.

A short definition of an RDBMS may be a DBMS in which data is stored in the form of tables and the relationship among the data is also stored in the form of tables.

Codd's Rules

• All database management must take place using the relational database's innate functionality
• All information in the database must be stored as values in a table
• All database information must be accessible through the combination of a table name, primary key and column name.
• The database must use NULL values to indicate missing or unknown information
• The database schema must be described using the relational database syntax
• The database may support multiple languages, but it must support at least one language that provides full database functionality (e.g. SQL)
• The system must be able to update all updatable views
• The database must provide single-operation insert, update and delete functionality




• Changes to the physical structure of the database must be transparent to applications and users.
• Changes to the logical structure of the database must be transparent to applications and users.
• The database must natively support integrity constraints.
• Changes to the distribution of the database (centralized vs. distributed) must be transparent to applications and users.
• Any languages supported by the database must not be able to subvert integrity controls.

Tags: database, table, DBMS, RDBMS, columns, Codd, E. F. Codd, rules, oracle, data

================================================ O************************O***********************O

Apt-Get command line tool

Apt-Get command line tool

(Ubuntu's Advanced Packaging Tool) !!!

The apt-get command is a powerful command-line tool used to work with Ubuntu's Advanced Packaging Tool (APT) performing such functions as installation of new software packages, upgrade of existing software packages, updating of the package list index, and even upgrading the entire Ubuntu system.

*Install package
#sudo apt-get install packagename

*Remove Package
#sudo apt-get remove packagename

*Install Multiple Packages
#sudo apt-get install packagename1 packagename2 packagename3

*Update the Package Index
#sudo apt-get update

The APT package index is essentially a database of available packages from the repositories defined in the /etc/apt/sources.list file.

*Upgrade the system
#sudo apt-get upgrade

*Read Debian APT User Manual
#sudo apt-get help

Tags: apt get apt-get advanced packaging tool install remove upgrade update help ubuntu linux unix package-management