What is the definition of DATABASE?
- An organized collection of logically related data
- Data can be searched, manipulated & sorted
- Can be of any size and complexity
What can users of a database do?
- Insert, retrieve and update database records
- Delete a record from the database
- Remove or delete database tables or files
What is the concept of a database in Computer Science?
- A SOFTWARE or PROGRAM that allows you to organize and store data in an electronic format on a computer
- The data can be searched, manipulated, sorted, analyzed and displayed quickly and efficiently
- The data can be of any size and complexity
- A database can be looked at as a computerized record-keeping system
What is the definition of DATA?
- Objects and events that are stored in a computer and have meaning
OBJECTS - Numbers, text, dates, documents, emails, images, audio, video, etc.
EVENTS - stored occurrences of business transactions., etc
What is the definition of STRUCTURED DATA?
- Data stored in a tabular form
- Names, addresses, etc.
What is the definition of UNSTRUCTURED DATA?
- Documents, emails, photos, images, sounds, etc.
What is the definition of INFORMATION?
- Data that has been processed in a way that increases the knowledge of the person using the data
- It can be summarized & represented for human interpretation (charts, graphs, etc)
What is the definition of METADATA?
- Data that describes the properties or characteristics of the data that is stored
- Stored description of the data in the database
- Helps describe what the data means
- Data about the data
What are the properties of METADATA
- Data names, definitions, length, size, type of allowed value.
What is the definition of a FILE PROCESSING SYSTEM?
- An early system which stored information in computer files
What is the definition of FILE?
- A collection of related records
Name 5 Disadvantages of File Systems…
- Program Data Dependence
- Duplication of Data
- Limited Data Sharing
- Lengthy development times
- Excessive Program Maintenance
Name the 3 Characteristics of THE DATABASE APPROACH…
- Central repository of shared data
- Data is managed by a controlling agent
- Data is stored in a standardized, convenient form
This requires a DATABASE MANAGEMENT SYSTEM (DBMS)
Describe PROGRAM DATA DEPENDENCE as it relates to the File Processing Approach.
Each program maintains its own metadata for each file they use. Any change in a file, will require work in each program that accesses that file, increasing maintenance costs.
Describe DUPLICATION OF DATA as it relates to the File Processing Approach.
Each program has its own copy of the same data. This is wasteful in terms of storage and maintenance costs
Describe LIMITED DATA SHARING as it relates to the File Processing Approach.
There is no centralized control of data. Files are private and owned by each program. This makes collaboration difficult.
Describe LENGTHY DEVELOPMENT TIMES as it relates to the File Processing Approach.
Each application programmer must design their own file formats.
Describe EXCESSIVE PROGRAM MAINTENANCE as it relates to the File Processing Approach.
Due to all of the other factors. Leads to high development costs.
Name 8 advantages to the database approach?
- Program-Data independence
- Planned data redundancy
- Improved data consistency
- Improved data sharing
- Improved Security
- Enforcement of standards
- Improved data quality
- Reduced program maintenance
Describe PROGRAM-DATA INDEPENDENCE as it relates to the database approach.
Metadata is separate from the data, so data can evolve without affecting the applications that process the data.
Describe PLANNED DATA REDUNDANCY as it relates to the database approach.
Data is less redundant, since data is centralized and better managed. There is reduction in wasted storage.
Describe IMPROVED DATA CONSISTENCY as it relates to the database approach.
Data is stored in one location, leading to better consistency
Describe IMPROVED DATA SHARING as it relates to the database approach.
Data can easily be shared among many users.
Describe IMPROVED SECURITY as it relates to the database approach.
There is control over who can access the system and what types of changes each individual is allowed to make.
