Relational database fundamentals
After completing this topic, you should be able to identify the basic principles of the relational model
1. Relational databases
Although certain aspects of the Oracle 10g Database are case and spacing insensitive, a common coding
convention has been used throughout all aspects of this course. This convention uses lowercase characters
for schema, role, user, and constraint names, for permissions, synonyms, and table names (with the exception
of the DUAL table), and for column names shown in code. Uppercase characters are used for keywords and
functions, for view, table, schema, and column names shown in text, for column aliases that are not shown in
quotes, and for data dictionary views. The spacing convention requires one space after a comma and one
space before and after operators that are not Oracle-specific, such as +, -, /, and <. There should be no space
between an Oracle-specific keyword or operator and an opening bracket, a closing bracket and a comma,
between the last part of a statement and the closing semicolon, or before a statement. String literals in single
quotes are an exception to all convention rules provided. Please use this convention for all interactive parts of
is an organized collection of related data.
The database structure may be simple or complex, depending on the nature of the information it contains and
the needs of database users.
To manage your databases, you use a database management system (DBMS) - a program that stores,
retrieves, and modifies data in databases in response to your commands and specifications.
Historically, hierarchical and network database models were used in database design. But while these
constitute an improvement on simple flat-file database models, they have significant limitations.
uses a relational database management system (RDBMS), which has advantages over previous
are structured using
rules and constraints