Database Administration and Data Models
class
A collection of objects
relational database
A database that represents data as a collection of tables (rows and columns) in which all data relationships are represented by common values in related tables
Primary Key
A field (or group of fields) that uniquely identifies a given entity in a table
data warehouse
A logical collection of information - gathered from many different operational databases - that supports business analysis activities and decision-making tasks
Entity Relationship Model
A logical representation of the data for an organization or for a business area, using entities for categories of data and relationships for associations between entities.
Foreign Key
A primary key of one table that appears as an attribute in another table and acts to provide a logical relationship between the two tables
Data Extraction
A process used to extract and validate data from an operational database and external data sources prior to their placement in a data warehouse.
Object
A real world entity
Database Security
A subset of information security that focuses on the assessment and protection of information stored in data repositories like database management systems and storage media.
Database Backup
Automatic dump facility that produces backup copy of the entire database
Types of Database Management Systems
- Hierarchical (oldest) - Relational (highest market share) - Object-Oriented (advanced use) - NoSQL (emerging)
Advantages of relational model
1. Data stored in relations 2. Easy to understand concepts 3. Easy to set up, change and manipulate (DDL and DML)
Functions of database administrator
1. Software installation and maintenance. 2. Data Extraction, Transformation 3. Database Backup and Recovery 4. Security 5. Authentication and Authorization 6. Performance Monitoring 7. Troubleshooting
Properties of relational tables
1. The values in every table are atomic 2. Each row is unique 3. All the values in a column have the same data type 4. The sequence of columns is insignificant 5. Each column has a unique name
Examples of Data Models
Entity Relationship Model Relational Model Hierarchical Model
troubleshooting
The process of analyzing a design problem and finding a way to fix it
Object oriented dbms
an approach to data management that stores both data and the procedures acting on the data as objects that can be automatically retrieved and shared; the objects can contain multimedia.
object-oriented programming
designing a program by discovering objects, their properties, and their relationships
Hierarchical database
format organizes data using a tree-like or organization chart type structure. Main data points can have multiple sub-data points associated with them referred to as parent child model.
Data models
logical data structures that detail the relationships among data elements using graphics or pictures
Database administration and maintenance
performing activities that support the database end user, including dealing with technical issues and ensuring satisfactory performance of applications for end users.
relational model
uses a two-dimensional table of rows and columns of data. Rows are records (also called tuples), and columns are fields (also referred to as attributes).
NoSQL databases
Non-tabular databases that can manipulate structured as well as unstructured data and inconsistent or missing data; are useful when working with Big Data.
Performance monitoring
a continuous process of collecting and analyzing data to compare how well a project is working against expected results of the project based on performance indicators. the goal is use the indicators to achieve efficiency where possible
Object oriented database
a major type of database that operates by storing data in objects rather than in tables