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Attribute: A field within a record. Domain:
All of the possible values contained in a particular field
for every record in the file. Entity: Anything about which
information can be stored; for example, a person, concept,
physical object, or event. It typically refers to a record
structure.
Entity-relationship (ER) model: A database
model that describes the attributes of entities and the relationships
among them.
Foreign key: A field in one table that is
indexed in another. Primary key: An indexed field that maintains
the primary sequence of the file/table.
Relationship: An association between two
entities or between an entity and itself.
Schema: The definition of an entire database.
Data Definition Language (DDL): Used to
specify a database scheme as a set of definitions expressed
in a DDL, DDL statements are compiled, resulting in a set
of tables stored in a special file called a data dictionary
or data directory, the data directory contains
metadata (data about data), the storage structure
and access methods used by the database system are specified
by a set of definitions in a special type of DDL called a
data storage and definition language, it
is meant to hide implementation details of the database schemes
from the users.
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