Entity Sets An entity is an object that exists and is distinguishable from other objects. Example:specific person,company,event,plant An entity set is a set of entities of the same type that share the same properties. Example:set of all persons,companies,trees,holidays An entity is represented by a set of attributes;i.e.,descriptive properties possessed by all members of an entity set. Example: instructor =(ID,name,street,city,salary course=(course_id,title,credits) A subset of the attributes form a primary key of the entity set;i.e.,uniquely identifiying each member of the set. Database System Concepts 7.8 @Silberschatz,Korth and SudarshanDatabase System Concepts 7.8 ©Silberschatz, Korth and Sudarshan Entity Sets An entity is an object that exists and is distinguishable from other objects. Example: specific person, company, event, plant An entity set is a set of entities of the same type that share the same properties. Example: set of all persons, companies, trees, holidays An entity is represented by a set of attributes; i.e., descriptive properties possessed by all members of an entity set. Example: instructor = (ID, name, street, city, salary ) course= (course_id, title, credits) A subset of the attributes form a primary key of the entity set; i.e., uniquely identifiying each member of the set