Lesson 1 Flashcards
(45 cards)
An effective information system provides users with accurate, timely, and relevant information.
Database
Data that have been processed into a form that is meaningful and useful to human beings.
Information
A collection of raw items such as words, numbers, images, and sounds that have not organized and arranged into a form that people can understand and use.
Data
A collection of related data organized in a manner that allows access, retrieval, use, and maintenance of that data.
Database
It allows you to create a computerized database; add, change, delete, and sort data; retrieve data from the database; and create forms and reports using the data.
Database Management System (DBMS)
A database, a DBMS, and the application programs that utilize the data in the database make up a _______________.
Database Environment
Benefits of Database
- Data Independence
- Data Consistency
- Controlled Redundancy
- Data Integrity
- Data Security
Low systems/programs maintenance
Data Independence
Due to the fact that each data item is held only once, there is no danger of an item being updated on one system and not on the other
Data Consistency
This means reducing to a minimum the number of data items, which are duplicated in a database.
Controlled Redundancy
The DBMS provides users with the ability to specify constraints on data such as making a field entry essential or using a validation routine
Data Integrity
The DBMS can ensure only authorized users are allowed access to the data.
Data Security
The principles of the relational model were first outlined by __________ in a June 1970 paper called A Relational Model of Data for Large Shared Data Banks
Dr. E. F. Codd
Stores all its data inside tables, and nothing more
Relational Database
It is very popular because of their ease of use and flexible structure
Relational Database Management Systems (RDBMS)
Components of the Relational Model
• Collections of objects or relations that store the data
• A set of operators that can act on the relations to produce other relations
• Data integrity for accuracy and consistency
A ____________ uses relations or two-dimensional tables to store information. _____________ are organized by fields, records, and tables.
Relational Database
It can be found at the intersection of a row and a column. There can be only one value in it
Field
The data or information for the database is stored in these _______. ________ are uniquely identified by their names and are comprised of columns and rows.
Tables
In relational database, table is also known as __________.
Relation
A single ________ or tuple representing all data required for a particular object.
Rows
A _________ or attribute contains one particular type of information about all the rows in the table. A _________ cannot, or should not, include one type of information for one row and another type for another row.
Column
A single field or combination of fields that uniquely defines a record. None of the fields that are part of the __________ can contain a null value. A table can have only one.
Primary Key
A field in a relational table that matches the primary key column of another table. It can be used to cross-reference tables.
Foreign Key
