Database Management System Mcq

DATABASE MANAGEMENT SYSTEM MCQ Which normal form is considered adequate for relational database design? ️ 3NF The column of a table is referred to as the ️ attribute. True statement: ️ Every relation in BCNF is also in 3NF. The data flow model of the application mainly shows ️ processing requirements and the flow of data. Given the basic ER and relational models, which of the following is incorrect? ️ In a row of a relational table, an attribute can have more than one value. In an airline reservation system, the entries are data flight number, place of departure, destination, type of plane, and seats available. The primary key is ️ flight number + date. An index is clustered if ️ the data records of the file are organized in the same order as the data entries of the index. A data model is a collection of conceptual tools for describing ️ data, data relationships, data semantics, and consistency constraints. Student and courses enrolled is an example of ️ many-to-many relationship. ER modeling technique is a ️ top-down approach. Third normal form is inadequate in situations where the relation ️ has multiple candidate keys/candidate keys that are composite/has overlapped candidate keys. Redundancy is dangerous as it is a potential threat to data ️ integrity consistency. An attribute of one table matching the primary key of another table is called as ️ foreign key. A primary key, if combined with a foreign key, creates ️ parent-child relationship between the tables that connect them. The employee salary should not be greater than 2000; this is ️ integrity constraint. Managers' salary details are hidden from the employee; this is ️ external level data hiding. Generally speaking, for a weak entity set to be meaningful, it must be a part of a ️ one-to-many relationship. If a relation scheme is in BCNF, then it is also in ️ first, second, and third normal form.