quiz - in another relation. 3. How would you identify...

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1. What is the difference between a database and a table? Database is a collection of persistent data that is used by the application systems of some given enterprise. Table is considered as a two dimensional structure composed of rows and columns. A table contains a group of related entities, which is an entity set. Table is also called as relation. 2. Why are entity and referential integrity important in a database? Relational design of databases begins by defining entities . An entity is simply a person, place, event, or thing for which we intent to collect data. A referential integrity maintains the integrity of set of relations. A referential integrity means, if a foreign key contains a value that refers to an existing valid tuple
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Unformatted text preview: in another relation. 3. How would you identify Primary Keys in a relation/table? A candidate key selected to uniquely identify all other attributes values in any given row is known as primary key . It cannot contain null entries. Through determination we can identify a key as primary key. The principle of determination is important because it is used in the definition of a central relational database concept known as functional dependence. Such candidate keys uniquely identify all other attributes values in a given row considered as primary key. SUBIN THOMAS AST JUNE 2004...
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This note was uploaded on 07/15/2011 for the course ECO 2023 taught by Professor Mr.raza during the Summer '10 term at FAU.

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