Data Management Flashcards
General approaches to data management
Flat-file approach
Database approach
Problems in a flat-file environment
Data redundancy (data storage, data updating, currency of information) Task-data dependency
Database approach
Centralizes data into a common database that is shared by other users
Elements of a database environment
- Database management systems
- Users
- Database administrator
- Physical database
- Database Management Systems Models
Features of DBMS
Program development
Backup and recovery
Database usage reporting
Database access
Three Software Modules for Database Access
Data definition language
Data manipulation language
Query language
Three Views of Data Definition Language
Internal view
Conceptual view
External view
Functions of a Database Administrator
Database planning Database design Database implementation Operations and maintenance Database growth and change
Two Fundamental Components of the Data Structure
Data Organization
Data Access Methods
Data Attribute/Field
Single item of data
Entity
Database representation of an individual resource, event, or agent about which we choose to collect data
Record Type
Data attributes that logically define an entity
Database
Set of record types
Associations
Relationship of record types
Three Types of Associations
One-to-One
One-to-Many
Many-to-Many
Three Common DBMS Models
Hierarchical
Network
Relational
Two Kinds of Databases
Centralized
Decentralized
Two Kinds of Distributed Databases
Partitioned
Replicated
Factors Considered in Solving a Deadlock
Resources invested in the transaction
Transaction’s stage of completion
Number of deadlocks associated with the transaction
Database Concurrence
Presence of complete and accurate data at all user sites
Categories of Controls Over Data Management Systems
Access controls
Backup controls
Risks of Access Controls
Corruption of data
Theft of data
Misuse of data
Destruction of data
Examples of Access Controls
User views Database authorization table (or Access control list) User defined procedures Data encryption Biometric devices Inference control
Backup and Recovery Features in A Database Environment
Database backup
Transaction log
Checkpoints
Recovery module
