DATABASE MANAGEMENT SYSTEM Flashcards
It is most often associated with so-called legacy systems and under this approach, data processing is by standalone applications rather than integrated systems.
Flat-file approach
In this type of situation, the organization incurs costs of multiple collections and storage procedures.
Data storage
Any changes in the records of one (1) department will not be automatically visible in other departments.
Data updating
In contrast to the problem of performing multiple updates is the problem of failing to update the file of all users affected by a change.
Currency of information
The user’s inability to obtain
additional information as his/her needs change.
Task-data dependency
Each data element is stored only once, eliminating data redundancy and reducing storage costs.
No data redundancy
This reduces the time and cost of keeping the database current.
Single update
A change any user makes to the database yields current data values for all other users
Current values
Users can access the full data domain available to the firm.
Task data independence
It is a software for creating and managing databases. It provides users and programmers a systematic way to create, retrieve, update, and manage data.
Database management system (DMS)
They are the first element of a database environment.
Users
These programs send data access requests (calls) to the DBMS, which validates the requests and retrieves the data for processing.
User application program
DBMS has a built-in query facility that allows authorized users to process data independently of professional programmers.
Direct query
It is considered the second element of a database environment and It provides a controlled environment to assist (or prevent) user access to the database and efficiently manage the data resource.
Database management system
This third element is responsible for the installation, configuration, upgrade, administration, monitoring, and maintenance of databases in an organization.
Database Administrator (DBA)
This fourth element of the database environment is considered the lowest level of the database, which serves as a collection of records and files.
Physical database
It is a database that stores data in a structured format using
rows and columns.
Relational database management system (RDBMS)
It corresponds to a row of a table and an attribute or field to a column.
Tuple
It composed of fields (attributes) and tuples.
Relation
It is a key field that serves as the unique identifier of a specific tuple in a relation.
Primary key
It is a field in one table whose values are constrained to be values of the primary key in another table.
Foreign key
This includes user interviews and other techniques to determine what
users do and what information they need to support their tasks.
Identify the views to be modeled
This involves creating and populating the physical tables with data. It is
an involved step that must be carefully planned and executed.
Construct the physical database
The normalized tables should be rich enough to support the views of all users of the system being modeled.
Prepare the user views
Each database is independent and functions on its own.
Autonomous
Data is distributed across the homogeneous nodes, and a central or master DBMS coordinates data updates across the sites.
Non-autonomous
Heterogeneous database systems are independent and integrated to function as a single database system.
Federated
Database systems employ a central coordinating module to access the databases.
Un-federated
