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2.1.2.1.4 Relational Model
There are three
terms
that
are
used
in
this
model:
relations,
attributes and domains. Relation can be described as a table with
columns and rows while the columns in the table are called
attributes. Finally there are domains, which is the set of the
attributes that are allowed to be taken.
2.1.2.2 Database
Management
System
Database Management System²
is a (or set) of programs
for
manipulate the
database. With DBMS we can retrieve and modify all the elements in the
database. Some examples of the DMBS are Oracle, MySQL and Microsoft
Access.
Normally
we
need
DBMS
to
create
a
Database
Systems.
According to Wikipedia.com, a DBMS include:
1. A modeling language to define the schema of each database hosted
in the DBMS, according to the DBMS data model.
2. Data structures (fields,
records,
files and objects) optimized to deal
with very
large amounts of data stored on a permanent data storage
device (which implies relatively slow access compared to volatile
main memory).
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