This blog will
discuss the relational database theory. Database is well known as a collection
of information this is organized so that it can be easily accessed, managed and
updated. Databases are usually classified by organizational approach. Originally,
databases were flat. All the information was stored in one long text file,
called a delimited file. It is difficult to search for specific information and
update those existed files. Then the relational database appears. It was
invented by E.F.Codd who is an IBM researcher in 1970.
What is the
difference between relational databases and normal databases? A relational
database is a collection of data that can be accessed, managed and reassembled
in many different ways. These data items are organized as a set of formally
described table. When people access it the system do not need to reorganize
these database tables. Today most of routine data transactions like accessing
bank accounts, using credit cards and buying thing online are all use
structures based relational database theory.
The structured
query language (SQL) can not be ignored if we want to discuss the relational
database theory. This structured query language is a kind of programming language
designed for managing data in a relational database management system (RDBMS).
It is the standard user and application program interface of relational
database. It is used for information interactive query from a relational
database and for gathering data to generate reports.
A relational
database is a set of tables including data fitted into predefined categories.
Files are represented by a table that stores information about different
entries. Each table (or sometimes called relation) contains one or more data
entries in columns. And each row represents an instant of data that related to
the entries defined by the columns. Here is a simple example of the database of
books.
In this example, each
row corresponds to one tuple and a column corresponds to an attribute. An
attribute is different named book’s information and each attribute is
associated with a domain. The advantages of the relational database are it is
easy to create and access because of the predefined categories. Except that, it
is easy to extend as well. A new data category can be added without requiring
the existing attributes.
Reference
http://computer.howstuffworks.com/question599.htm
http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/reldb/
http://searchsqlserver.techtarget.com/definition/database
http://searchsqlserver.techtarget.com/definition/relational-database
http://www.techrepublic.com/article/relational-databases-the-inspiration-behind-the-theory/
Comment
I thought your post was interesting and liked that you included the difference between relational databases and the older databases. It really demonstrated the significant increase in data storage and manipulation capabilities. The use of linked tables instead of having to search through text files increases the ease and possibilities of using the data that we have.
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