Database Management Systems Interview Questions/Answers YASH PAL, 19 March 202228 June 2025 The database management system is a management system to stores the data for any application. so in the concept of building a dynamic application, we always need for Database, and to manage that we need a database management system.So it’s a big topic for interviews and has a high chance to be asked in an interview about the DBMS. so here we are including some basic to advanced Database management systems (DBMS) Interview questions and answers so one can prepare for this topic very well and crack the coding interviews or can use them in coding competitions, and university exams.Which normal form is considered adequate for relational database design?2 NF3 NF4 NFBCNFAnswer – (2) 3 NFThe concept of locking can be used to solve the problem oflost updateuncommitted dependencyinconsistent datadeadlock 1 and 42, 3 and 41, 2 and 3All 1, 2, 3, and 4 can be solvedAnswer – (3) 1, 2 and 3If every non-key attribute is functionally dependent on the primary key, then the relationship will be infirst normal formsecond normal formthird normal formfourth normal formAnswer – (3) third normal form The column of a table is referred to as thetupleattributeentitydegreeAnswer – (2) attributeGiven the functional dependenciesX → W; X → Y; Y → Z and Z → PQwhich of the following does not hold goodX → ZW → ZX → WYNone of the aboveAnswer – (2) W → ZWhat are the potential problems when a DBMS executes multiple transactions concurrently?The lost update problemThe dirty read problemThe unrepeatable read problemThe phantom problem3 and 4 only1, 2, and 4 only2 and 3 onlyAll of 1, 2, 3 and 4Answer – (4) All of 1, 2, 3 and 4The data flow model of an application mainly showsthe underlying data and the relationships among themprocessing requirements and the flow of datadecision and control informationcommunication network structureAnswer – (2) processing requirements and the flow of dataWhich of the following desired features are beyond the capability of relational algebra?Aggregate computationMultiplicationFinding transitive closureAll of the aboveAnswer – (4) All of the aboveIn an airline reservation system, the entities are data, flight number, place of departure, destination, type of plane, and seats available. The primary key isfligh numberfligh number + place of departurefligh number + datefligh number + destinationAnswer – (3) flight number + dateFor a database relation R(a,b,c,d) where the domains of a, b, c, and d include only atomic values, only the following functional dependencies and those that can be inferred from their hold.a → cb → dThe relation is infirst normal form but not in the second normal formsecond normal form but not in the third normal formthird normal formnone of the aboveAnswer – (1) First normal form but not in second normal formIn an E-R diagram, ellipses represententity setsrelationship among entity setsattributesthe link between attributes and entity setsAnswer – (3) attributesThe set of permitted values of each attribute is called itsattribute setattribute rangedomaingroupAnswer – (3) domainA data model is a collection of conceptual tools for describingdata and data relationshipsdata semantics and consistency constraintsdata, data relationship, data semantics, and consistency constraintsnone of the aboveAnswer – (3) data, data relationship, data semantics, and consistency constraintsChoose the incorrect statementsIn a network model, data is represented by a collection of records, and relationships among data are represented by links.In a hierarchical model, data and relationships among data are represented by records and links respectively.In a hierarchical model, the records are organized as a collection of arbitrary graphs.In the network model, the records are organized as a collection of trees.1 and 3 only2 and 3 only3 and 4 onlyAll are correctAnswer – (4) All are correctChoose the correct statements.An alternate key is a candidate key that is not a primary keyAn alternate key is a primary key that is not a candidate keyAn alternate key is a candidate key that is also a primary keyNone of the aboveAnswer – (1) An alternate key is a candidate key that is not a primary keyThe e-R modeling technique is atop-down approachbottom-up approachleft-right approachboth top-down and bottom-upAnswer – (1) top-down approachThe third normal form is inadequate in situations where the relationhas multiple candidate keyshas candidate keys that are compositehas overlapped candidate keysAll of the aboveAnswer – (4) All of the aboveRedundancy is dangerous as it is a potential threat to dataintegrityconsistencysufficiencyboth (a) and (b) aboveAnswer – (4) both (a) and (b) aboveAn attribute of the table matching the primary key of another table is called asforeign keysecondary keycandidate keycomposite keyAnswer – (1) Foreign keyChoose the correct statementNetwork models are complicated by physical keys, but the relational model is faster because it uses logical keys.Network models are complicated by logical keys, but the relational model is faster because it uses physical keys.Network models are complicated by logical keys, but the relational model is slower because it uses physical keys.Network models are complicated by physical keys but the relational model is slower because it uses logical keys.Answer – (1) Network models are complicated by physical keys, but the relational model is faster because it uses logical keys.Note – More interview questions and answers will be added from time to time. 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