DBMS Topics
HubUnit 1 — Introduction to DBMS & Entity-Relationship ModelAdvantages and Disadvantages of DBMSAggregationCharacteristics of DBMSData IndependenceData ModelsDatabase Users and AdministratorsDBMS LanguagesER DiagramsEntity-Relationship ER ModelIntroduction to DBMSKeys in DBMSRelationships and CardinalitySchema and InstanceSpecialization and GeneralizationUnit 1 Summary — Introduction to DBMS & ER ModelThree-Level Architecture ANSI/SPARC ArchitectureWeak Entity SetUnit 2 — Relational Model & SQLConstraints in SQLCursorsDCL and TCL CommandsDDL CommandsDML CommandsDomain Relational Calculus DRCFunctions and Stored ProceduresJoins in SQLNested Queries SubqueriesRelational AlgebraRelational CalculusRelational ModelSQL IntroductionUnit 2 Summary — Relational Model & SQLTriggers in SQLTuple Relational Calculus TRCViews in SQLArmstrong's Axioms & Closure of AttributesBoyce-Codd Normal Form BCNFClosure of AttributesDependency PreservationFifth Normal Form 5NFFirst Normal Form 1NFFourth Normal Form 4NFFunctional DependencyLossless DecompositionMultivalued DependencyNormal Forms — OverviewNormalization — IntroductionSecond Normal Form 2NFUnit 3 Summary — NormalizationThird Normal Form 3NFUnit 4 — Transaction Management & Concurrency ControlACID PropertiesCheckpointsConcurrency Control & SerializabilityDeadlock in DBMSLock-Based Protocols & Two-Phase LockingLog-Based RecoveryRecovery SystemSerializabilityShadow PagingUnit 4 Summary — Transaction Management & Concurrency ControlTimestamp-Based ProtocolTransaction ManagementTransaction StatesTwo-Phase Locking 2PLUnit 5 — Storage & IndexingB+ TreeB-TreeCost EstimationDynamic HashingFile OrganizationHashing TechniquesIndexing — IntroductionMulti-Level IndexingQuery OptimizationQuery ProcessingSingle-Level IndexingStatic HashingUnit 5 Summary — Storage & IndexingUnit 6 — Advanced Topics in DBMSBig Data and DBMSCloud DatabaseData MiningData WarehouseDatabase SecurityDistributed DatabaseDistributed Query ProcessingDistributed DBMS Architecture, Fragmentation & ReplicationMongoDB — IntroductionNoSQL DatabaseReplication in Distributed DatabasesUnit 6 Summary — Advanced Topics in DBMSViva Voce — DBMSImportant Viva Questions — DBMSInterview Questions — DBMSViva Answers — DBMSDBMS Multiple Choice Questions MCQsDBMS Lab Programs
Important Viva Questions — DBMS
Last Updated : 21 May, 2026
1. What is a DBMS? How is it different from a file system?
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Unit 1 — Introduction & ER Model
- What is a DBMS? How is it different from a file system?
- What are the four main characteristics of a database?
- What is the three-level ANSI/SPARC architecture?
- Define logical and physical data independence.
- What is a schema? How does it differ from an instance?
- What are the different types of database users?
- What is the role of a Database Administrator (DBA)?
- What are the main components of a DBMS?
- Define an entity, attribute, and relationship in the ER model.
- What is the difference between a simple and composite attribute?
- What are the different types of keys in a database?
- What is the difference between primary key and candidate key?
- What is a foreign key? How does it enforce referential integrity?
- What is cardinality? Explain the types with examples.
- What is a weak entity? How is it represented in an ER diagram?
- What is specialization? How is it different from generalization?
- What is aggregation in an ER model?
- What are the different data models? Compare hierarchical and relational models.
Unit 2 — Relational Model & SQL
- Define a relation, tuple, and attribute in the relational model.
- What are the properties of a relational table?
- What is relational algebra? Name its basic operations.
- What is the difference between selection and projection in relational algebra?
- What is a natural join? How does it differ from a theta join?
- What is relational calculus? Differentiate TRC and DRC.
- What is the difference between DDL, DML, DCL, and TCL?
- What are integrity constraints in SQL?
- What is the difference between DELETE, TRUNCATE, and DROP?
- Explain the different types of SQL joins with examples.
- What is a nested query (subquery)? When is it used?
- What is a correlated subquery?
- What is a view? What are its advantages and limitations?
- What is a trigger? When does it fire?
- What is the difference between a function and a stored procedure?
- What is a cursor? When is it used in PL/SQL?
Unit 3 — Normalization
- What is normalization? Why is it needed?
- What is a functional dependency? Give an example.
- What is a partial functional dependency?
- What is a transitive functional dependency?
- State Armstrong's axioms and their names.
- What is the closure of a set of attributes?
- What is a canonical cover?
- Define 1NF, 2NF, and 3NF with examples.
- What is BCNF? How does it differ from 3NF?
- When can a relation be in 3NF but not in BCNF?
- What is a multivalued dependency?
- What is 4NF?
- What is 5NF (Project-Join Normal Form)?
- What is lossless decomposition? How is it tested?
- What is dependency preservation?
Unit 4 — Transactions & Concurrency
- What is a transaction? What are its states?
- Explain the ACID properties of a transaction.
- What is a schedule? What is a serial schedule?
- What is serializability? What are its types?
- What is conflict serializability?
- What is a precedence graph? How is it used?
- What is a lock? What are the types of locks?
- What is two-phase locking (2PL)?
- What is strict 2PL?
- What is a deadlock? How is it detected and resolved?
- What is the timestamp ordering protocol?
- What is a dirty read, non-repeatable read, and phantom read?
- What is the write-ahead log (WAL) protocol?
- What is a checkpoint? Why is it used?
- What is shadow paging?
Unit 5 — Storage & Indexing
- What is file organization? Name its types.
- What is indexing? What are its advantages?
- What is the difference between dense and sparse index?
- What is a primary index vs. a secondary index?
- What is a clustered index vs. a non-clustered index?
- What is a multi-level index?
- What is a B-tree? What are its properties?
- What is a B+ tree? How does it differ from a B-tree?
- What is static hashing?
- What is dynamic hashing (extendible hashing)?
- What is query processing? What are its steps?
- What is query optimization?
- What is cost estimation in query optimization?
Unit 6 — Advanced Topics
- What is a distributed database? What are its advantages?
- What is fragmentation? Name its types.
- What is horizontal fragmentation vs. vertical fragmentation?
- What is replication in a distributed database?
- What is a NoSQL database? How does it differ from a relational database?
- What are the types of NoSQL databases?
- What is MongoDB? What is a document in MongoDB?
- What is Big Data? What are its characteristics (5 Vs)?
- What is a data warehouse? How is it different from a database?
- What is data mining?
- What is a cloud database?
- What is database security? What are authorization and authentication?
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