DBMS Viva Questions With Answer - SPPU
Database Management System Viva Question Answers
What is Database ?
A database is an organized collection of data, so that it can be easily accessed and managed
What is Database Management System ?
Database management system is a software which is used to manage the database
What are the types of DBMS ?
Relational database.
Object oriented database.
Hierarchical database.
Network database
What is ER Model ?
Entity Relationship Model (ER Modeling) is a graphical approach to database design
What is Entity ?
An entity is a real world object which can can be easily identifiable. For example, in a school database, students, teachers, classes, and courses offered can be considered as entities. All these entities have some attributes or properties that give them their identity.
What is Attribute ?
An attribute is a property or characteristic of an entity
What is Constraints ?
Constraints are the conditions forced on the columns of the table to meet the data integrity
What is Key ?
Keys are very important part of Relational database model. They are used to establish and identify relationships between tables and also to uniquely identify any record or row of data inside a table. These are used in identifying and establishing relationships between tables
What is Indexing ?
Indexing is used to optimize the performance of a database by minimizing the number of disk accesses required when a query is processed
What is Primary Key ?
The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys must contain UNIQUE values, and cannot contain NULL values.
What is Foreign Key ?
A Foreign Key is a database key that is used to link two tables together
What is Candidate Key ?
Candidate key is a single key or a group of multiple keys that uniquely identify rows in a table
What is Super Key ?
A super key is a combination of columns that uniquely identifies any row within a relational database management system (RDBMS) table
What is Unique Key ?
Unique key is a constraint that is used to uniquely identify a tuple in a table
What is DDL ?
Data Definition Language -It Consist SQL commands that can be used to define the database schema
State DDL Command
CREATE
DROP
ALTER
TRUNCATE
COMMENT
RENAME
What is DML ?
Its full form is Data Manipulation Language .DML commands are used to modify the database. It is responsible for all form of changes in the database
State DML Command
NSERT
UPDATE
DELETE
LOCK
CALL
EXPLAIN PLAN
What is Normalization ?
Normalization is the process of reorganizing data in a database so that redundancy can removed.
What is Denormalization ?
Denormalization is a database optimization technique in which we add redundant data to one or more tables
What is Redundancy ?
Redundancy means having multiple copies of same data in the database
What is Cursor ?
Cursor is a Temporary Memory or Temporary Work Station. It is Allocated by Database Server at the Time of Performing operations User.
What is Implicit Cursor ?
Implicit Cursors are also known as Default Cursors of SQL SERVER. These Cursors are allocated by SQL SERVER when the user performs DML operations.
What is Explicit Cursor ?
Explicit Cursors are Created by Users whenever the user requires them. Explicit Cursors are used for Fetching data from Table in Row-By-Row Manner.
What is Trigger ?
Triggers are the SQL statements that are automatically executed when there is any change in the database
What is SQL ?
SQL (Structured Query Language) is a standardized programming language that's used to manage relational databases and perform various operations on the data in them
What is NoSQL ?
NoSQL databases, also known as not only SQL are non-tabular databases that provides a mechanism for storage and retrieval of data.
What is MongoDB ?
MongoDB is an open-source document database and leading NoSQL database which uses JSON-like documents with optional schemas.MongoDB is a document-oriented NoSQL database used for high volume data storage. Instead of using tables and rows as in the traditional relational databases, MongoDB makes use of collections and documents. Documents consist of key-value pairs which are the basic unit of data in MongoDB
What is The Full Form Of JSON ?
JSON (JavaScript Object Notation)
What is XML ?
XML is a markup language much like HTML · XML was designed to store and transport data. Its extension is .xml
What is Clause ?
Clauses are in-built functions available to us in SQL. With the help of clauses, we can deal with data easily stored in the table
What is Aggregate Function ?
Aggregate functions in DBMS take multiple rows from the table and return a value according to the query. Various Aggregate Functions
1) Count()
2) Sum()
3) Avg()
4) Min()
5) Max()
Differentiate Between char & varchar
CHAR is fixed length and VARCHAR is variable length
Differentiate Between Delete & Truncate
DELETE is a DML(Data Manipulation Language) command and is used when we specify the row(tuple) that we want to remove or delete from the table or relation.
TRUNCATE is a DDL(Data Definition Language) command and is used to delete all the rows or tuples from a table
What is RDBMS ?
RDBMS stands for Relational DataBase Management Systems. It is basically a program that allows us to create, delete, and update a relational database.
What is Views ?
Views in SQL are kind of virtual tables
What is PL/SQL ?
PL/SQL is an extension of SQL language that combines the data manipulation power of SQL with the processing power of procedural language. Its full form is Procedural Language for SQL
What is ROLLBACK ?
ROLLBACK in SQL is a transactional control language which is used to undo the transactions that have not been saved in database
What is COMMIT ?
COMMIT in SQL is a transaction control language which is used to permanently save the changes done in the transaction in tables/databases
What is Stored Procedure ?
A stored procedure is a subroutine available to applications that access a relational database management system
What is Checkpoint ?
The checkpoint is a type of mechanism where all the previous logs are removed from the system and permanently stored in the storage disk
What is Deadlock ?
In a database, a deadlock is an unwanted situation in which two or more transactions are waiting indefinitely for one another to give up locks
What is SAVEPOINT ?
SAVEPOINT command is used to temporarily save a transaction so that you can rollback to that point whenever required.
What is Transaction ?
A transaction can be defined as a logical unit of work on the database
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