data models Flashcards
what data base design focuses on
how the database structure will be used to store and manage end user data
what is the attribute
is characteristic of any entity
what is the relationship
describes an association among entities
what is the constraint
is a restriction placed on data constraint are important because they help to ensure data integrity
what is business rule
is a brief precise and unambiguous description of a policy procedure or principle within a specific organization
entity is noun
relationship is verb
true or false
true
what is the segment
is the equivalent of a file system record type
what is the schema
which is the conceptual organization of the entire database as viewed by the database administrator
what is the subschema
which defines the portion of the database “seen”nby the application programs that actually produce the desired information from the data contained within the database
what is the data management language (DML)
which defines the environment in which data can be managed and to work with the data in the database
what is the schema data definition language (DDL)
which enable the database administrator to define the schema components
in relational
every row is tuple
each column is attribute
true or false
true
what is the file
a table with complete data and structural independence
what is SQL
is structured query language
what is the components of database application
user interface
a set of tables
stored in the database
and SQL ENGINE
what is the SQL
is a declerative language that tell what must be done but not how it must be done
what is the entity
anything about which data are to be collected and stored
rectangle
also known entity box
what is the entity set
a collection of like entities
what is the class
is a collection of similar objects with shared structure and the behavior
what is the inheritance
is the ability of an object within the class hierarchy to inherit the attributes and the methods of the classes above
what is unified modeling language
is a language based on OO concepts that describes a set of diagrams and symbols that can be used to graphically model a system
