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A database management system, or DBMS, gives the
user access to their data and helps them transform
the data into information. Such database management
systems include dBase, Paradox, IMS, and Oracle.
These systems allow users to create, update, and
extract information from their databases. Compared
to a manual filing system, the biggest advantages to
a computerized database system are speed, accuracy,
and accessibility.
A database is a structured collection of data. Data
refers to the characteristics of people, things, and
events. Oracle stores each data item in its own
field. For example, a person's first name, date of
birth, and their postal code are each stored in
separate fields. The name of a field usually
reflects its contents.
A postal code field might be named POSTAL-CODE or
PSTL_CD. Each DBMS has its own rules for naming the
data fields.
A field has little meaning unless it is seen within
the context of other fields. The postal code T6G
2H1, for example, expresses nothing by itself. To
what person or business does it belong? The postal
code field is informative only after it is
associated with other data. In Oracle, the fields
relating to a particular person, thing, or event are
bundled together to form a single, complete unit of
data, called a record (it can also be referred to as
a row or an occurrence). Each record is made up of a
number of fields. No two fields in a record can have
the same field name.
During an Oracle database design project, the
analysis of your business needs identifies all the
fields or attributes of interest. If your business
needs change over time, you define any additional
fields or change the definition of existing fields.
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