Databases Flashcards
What is a database?
A database is a place that stores information in an organized way. It helps us organize a lot of data and lets us organize data fast. There are many types of databases. In a database information is arranged in a table. A database helps us organize, manipulate data without losing it. Each row is called a record and each column is called a field.
What are the advantages of a database?
The advantage of a database is that it contains files stored in many locations in multiple systems, this can cause multiple copies of the same file, this is prevented in a database as there is only one database and if there are copies you will be informed.
How can we share data in a database
There are many remote users that can access the database simultaneously and share data between themselves. Various level of authorizations access is there. Data can be shared based on the authorization protocols being followed.
What is data integrity?
Data is accurate and consistent. It is important as there are multiple databases containing data visible to many users and makes sure that the data doesn’t get mixed up.
What is a database model?
A database model determines the logical structure of a database. Fundamentally determines in which manner data can be stored/organized /manipulated. There are 3 types of databases, Hierarchical database, network database, and relational database.
What is a Hierarchical database?
This is one of the oldest database models, developed by IBM for information management. It is organized in a tree-like structure and is barely used anymore. The structure is like a tree with nodes.
What is a Network Database?
In a network database, the data is organized more like a graph. Allows many to many relationships. It has a simple and easy design. It can handle one to many and many to one relationship. The structure is complex. Insertion requires deletion and updating that needs pointer changes. Structural changes are very hard.
What is a Relational Database?
A relational database is arranged in rows and columns/ It requires tables for each subtopic. It is the most popular database. Data is easier to understand and is easy to access and modify data. Easier to maintain security.
