Chapter 3: Data and business intelligence Flashcards
Database
an organized collection of structured information, or data, typically stored electronically in a computer system.
- collection of related data
Benefits of a database
- Improved data management
- Data redundancy is eliminated or minimized
- Storage space is used more efficiently
Feilds
columns
Records
rows
File Access methods
- Sequential access = records are organized sequentially. (used for archives and backups)
- Random access = not in any order. Faster for accessing few records
- Indexed sequential access = combination
Two ways information is viewed in a database
- Physical view = how data is stored and retrieved. (only one type of physical view)
2.Logical view = how information appears to users. (can be more than one logical view)
Data models 3 components
- Data structure = describes how data is organized
2.Operations = describes methods and calculations that can be preformed - Integrity rules = defines boundaries of a database
Database design models (3)
- Hierarchical model = the relationship among records from a tree like structure
- Network model
- Relational model = 2 dimensional table of records and columns
Primary key
uniquely identifies each record in a relational database
Foreign key
A field in a relational table that matches the primary key field of another table. It is used to reference the tables and attach them.
Normalisation
Improves database efficiency by eliminating redundant data
DBMS = database management system
Software for creating , storing and maintaining and accessing database files
Database engine
the underlying software component that a database management system (DBMS) uses to create, read, update and delete (CRUD) data from a database.
- The heart of the DBMS
Data manipulation
the process of organizing or arranging data in order to make it easier to interpret. (adding, deleting, retrieving records from a database)
components of a DBMS
- Database engine
- Data definition
- Data manipulation
- Application generation
- Data administration
Distributed databases
Data is stored on more than one server throughout the company
Object oriented databases
1.Both data and their relationships are contained in a single object.
2.An object consists of attributes and methods that can be performed on the object’s data.
Data warehouse
Collection of data from different sources used to support decision-making applications and generate business intelligence
Characteristics of data in a data warehouse (Functions)
1.Subject oriented – focus on specific area
2.Integrated – comes from variety of sources
3.Time variant – categorized based on time
4.Type of data – captures aggregated data
5.Purpose – used for analytical purposes
Components of a data warehouse
- Input
- Extraction, transformation and loading (ETL)
3.Storage
4.Output
Extraction as a component of a data warehouse
extraction = collecting data from a variety of sources
- converting data into the format that can be used in the transformation process
Transformation processing as a component of data warehousing
makes sure data meet the data warehouse’s needs
Ways information is organized in a data warehouse
- Raw data = original form
- Summary data
- Metadata = data about data”. Metadata is defined as the data providing information about one or more aspects of the data
Output
Data warehouse supports different types of analysis and generates reports for decision making.
1.Online analytical processing
2.Data mining analysis
3.Decision making reports
