This chapter discusses techniques for securing databases against a variety of threats. It also presents schemes of providing access privileges to authorized users.
A database system is a collection of interrelated data and a set of programs that allow users to access and modify these data. A major purpose of a database system is to provide users with an abstract view of the data. That is, the system hides certain details of how the data are stored and maintai...
A relational database is based on the relational model and uses a collection of tables to represent both data and the relationships among those data.
A transaction consists of a sequence of query and/or update statements .
The main idea of Sampling Algorithm is to select a small sample , one that fits in main memory , of the database of transaction
Four main control measures are used to provide security of data in databases: Access control, Inference control, Flow control, Data encryption
The individual entity instances in an entity set and the individual relationship instances in a relationship set. In ER diagrams the emphasis is on representing the schemas rather than the instances.