Relative database theory is a method of storing and
manipulating data that simplifies these processes so that the user can access information
without knowing the exact structure of the database and having an advanced
knowledge of programming. The basic principle behind the theory is the grouping
of objects into tables, referred to as relations, which share the same defined
attributes. In each table, a row represents an object, that can be either a
physical entity or abstract, and is given a primary key that is used to
reference to other tables. Each column then represents a specific attribute of
the object. The definition of each attribute must fall in the same domain and
follow the same constraints in each table. This allows for a definition of
constraints for all members of a relation, rather than each individual and
ensures all objects are defined with the right type of value, such as making
sure it is defined with a number or letter. Derived relations can then be
created by referencing other relations with relational operators to create a
new table that is then treated as a single entity. This can either be done as a
one-to-one link, or a combination of different objects using functions such as union
or difference.
As Laura Worley mentioned, relational databases are widely
used. This type of database is useful because it allows the user to link
changes to the relevant objects so only one change needs to be made for the
entire system to be updated. In addition, indexes can be used to obtain data
quickly and easily, in the way that you want it to be presented. For example,
banks use relational databases to store customers’ information, where each row
is a customer and each column is more information for that customer, such as
the name, address, and financial information. This allows employees to search a
customer’s name or account number and obtain all the relevant information for
that customer. In addition, the use of splitting the data into derived relations
that can be classified as confidential and non-confidential information allows
for increased security as the users can be allowed to see only the tables they
are granted access to. In the bank example, for instance, a bank teller can add
money to your account without being able to see your private information such
as your social security number.
Sources:
"Advantages of a Relational Database." Teach-ICT.
N.p., n.d. Web. 07 Feb. 2016.
<http:// www.teach-ict.com/as_as_computing/ocr/H447/F453/3_3_9/database_design/miniweb/pg8.htm>.
Hull, Sean. "RELATIONAL DATABASE – WHAT IS IT AND WHY
IS IT IMPORTANT?" Scalable Startups. N.p., 05 July 2011. Web. 07
Feb. 2016.
<http://www.iheavy.com/2011/07/05/ relational-database-what-is-it-and-why-is-it-important/>.
"Relational Database." Icons of Progress.
IBM100, n.d. Web. 07 Feb. 2016. <http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/reldb/>.
"Relational Database." Wikipedia. Wikimedia
Foundation, 18 Jan. 2016. Web. 07 Feb. 2016.
<https://en.wikipedia.org/wiki/Relational_database>.
Comments:
Yuanjin Li
Haoying Ye
Comments:
Yuanjin Li
Haoying Ye
I didn't know banks used these databases to store information, that's really interesting. It's good that they can store confidential information along with information that isn't confidential side-by-side without it impacting the security of the bank. I wonder if this will change as hacking becomes more and more prevalent.
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