chapter 5 database1 Flashcards
conceptual model:
the logical structure of the entire database
conceptual schema:
another term for logical schema
data independence:
the immunity of user applications to changes made in the definition and organization of data
data model:
a collection of concepts or notations for describing data, data relationships, data semantics and data constraints
data modelling:
the first step in the process of database design
database logical design:
defines a database in a data model of a specific database management system
database physical design:
defines the internal database storage structure, file organization or indexing techniques
entity relationship diagram (ERD):
a data model describing the database showing tables, attributes and relationships
external model:
represents the user’s view of the database
external schema:
user view
Internal model:
a representation of the database as seen by the DBMS
logical data independence:
the ability to change the logical schema without changing the external schema
logical design:
where you create all the tables, constraints, keys, rules, etc.
logical schema:
a conceptual design of the database done on paper or a whiteboard, much like architectural drawings for a house
operating system (OS):
manages the physical level of the physical model
