What is a database?
a. A collection of files stored on a computer
b. A structured collection of data organized for efficient retrieval
c. A type of computer program
d. A network of connected computers
Answer: b. A structured collection of data organized for efficient retrieval
Which of the following is NOT a type of database model?
a. Relational
b. NoSQL
c. Hierarchical
d. Algorithmic
Answer: d. Algorithmic
What is SQL an acronym for?
a. Structured Query Language
b. Sequential Query Language
c. System Query Language
d. Simplified Query Language
Answer: a. Structured Query Language
Which database model uses a schema-less approach and is suitable for handling unstructured data?
a. Relational
b. NoSQL
c. Hierarchical
d. Object-Oriented
Answer: b. NoSQL
What is a primary key in a relational database?
a. A key used for encryption
b. A unique identifier for each record in a table
c. A key used for foreign key relationships
d. A key that can be null
Answer: b. A unique identifier for each record in a table
What is the primary purpose of a database management system (DBMS)?
a) Data visualization
b) Data storage and retrieval
c) Web development
d) Graphic design
Answer: b Data storage and retrieval
Which SQL command is used to retrieve data from a database?
a. SELECT
b. UPDATE
c. DELETE
d. INSERT
Answer: a. SELECT
What is the purpose of the JOIN clause in SQL?
a. To add new records to a table
b. To update existing records in a table
c. To combine data from multiple tables
d. To delete records from a table
Answer: c. To combine data from multiple tables
Which type of database index is typically used to improve query performance on columns with high cardinality?
a. Primary index
b. Secondary index
c. Clustered index
d. Non-clustered index
Answer: d. Non-clustered index
In a relational database, what does ACID stand for?
a. Atomicity, Consistency, Integrity, Durability
b. Association, Concurrency, Inheritance, Design
c. Allocation, Configuration, Inversion, Deletion
d. Accumulation, Compatibility, Integration, Decryption
Answer: a. Atomicity, Consistency, Integrity, Durability
Which of the following is NOT a data type commonly used in SQL?
a. Integer
b. Boolean
c. String
d. Decimal
Answer: b. Boolean
What is the primary goal of data normalization in database design?
a) To minimize data redundancy
b) To increase data complexity
c) To enhance data visualization
d) To improve data retrieval speed
Answer: a) To minimize data redundancy
What is the purpose of the GROUP BY clause in SQL?
a. To order the result set in ascending order
b. To filter rows based on a condition
c. To group rows with the same values into summary rows
d. To perform mathematical calculations on numeric columns
Answer: c. To group rows with the same values into summary rows
Which SQL statement is used to add new records to a table?
a. SELECT
b. UPDATE
c. DELETE
d. INSERT
Answer: d. INSERT
What is normalization in the context of database design?
a. The process of simplifying complex SQL queries
b. The process of organizing data in a database to minimize redundancy
c. The process of encrypting sensitive data in a database
d. The process of creating backup copies of a database
Answer: b. The process of organizing data in a database to minimize redundancy
What is a foreign key in a relational database?
a. A key used for encryption
b. A key that uniquely identifies each record in a table
c. A key used to establish relationships between tables
d. A key that cannot be null
Answer: c. A key used to establish relationships between tables
What does CRUD stand for in the context of database operations?
a. Create, Read, Update, Delete
b. Compute, Render, Update, Display
c. Control, Record, Undo, Delete
d. Create, Render, Undo, Display
Answer: a. Create, Read, Update, Delete
Which SQL command is used to modify existing data in a database?
a. SELECT
b. UPDATE
c. DELETE
d. INSERT
Answer: b. UPDATE
What is the purpose of an index in a database?
a. To store large binary files
b. To enforce data integrity constraints
c. To improve data retrieval speed
d. To perform mathematical calculations
Answer: c. To improve data retrieval speed
Which type of SQL constraint ensures that a column does not contain NULL values?
a. PRIMARY KEY constraint
b. UNIQUE constraint
c. NOT NULL constraint
d. CHECK constraint
Answer: c. NOT NULL constraint
What is the role of a DBA (Database Administrator) in database management?
a. Writing application code
b. Designing user interfaces
c. Managing and maintaining the database system
d. Analyzing market trends
Answer: c. Managing and maintaining the database system
Which SQL command is used to remove records from a table?
a. SELECT
b. UPDATE
c. DELETE
d. INSERT
Answer: c. DELETE
What is the purpose of the WHERE clause in SQL?
a. To specify the columns to be selected in a query
b. To specify the order of the result set
c. To filter rows based on a condition
d. To group rows by a specific column
Answer: c. To filter rows based on a condition
What is the primary purpose of a DBMS (Database Management System)?
a. To create user interfaces
b. To organize files on a computer
c. To manage and manipulate data in a structured way
d. To perform mathematical calculations
Answer: c. To manage and manipulate data in a structured way
In a relational database, what is a tuple?
a. A data type
b. A field name
c. A record or row
d. A database schema
Answer: c. A record or row
Which SQL command is used to modify the structure of a database table, such as adding a new column?
a. SELECT
b. UPDATE
c. ALTER
d. INSERT
Answer: c. ALTER
What is the purpose of the COMMIT statement in SQL?
a. To permanently save changes made to a database
b. To retrieve data from a database
c. To create a new database
d. To delete records from a database
Answer: a. To permanently save changes made to a database
What is an entity-relationship diagram (ERD) used for in database design?
a. To display the contents of a database table
b. To represent the relationships between entities in a database
c. To perform mathematical calculations
d. To generate SQL queries
Answer: b. To represent the relationships between entities in a database
Which of the following is a key characteristic of a NoSQL database?
a. Fixed schema
b. ACID compliance
c. Tabular data representation
d. Flexible schema
Answer: d. Flexible schema
What is the purpose of the ROLLBACK statement in SQL?
a. To permanently save changes made to a database
b. To undo changes made during a transaction
c. To create a new database
d. To retrieve data from a database
Answer: b. To undo changes made during a transaction
In a relational database, what is a foreign key constraint used for?
a. To enforce data integrity by ensuring that values in one column match values in another column
b. To automatically generate primary keys
c. To define the data type of a column
d. To create indexes for fast data retrieval
Answer: a. To enforce data integrity by ensuring that values in one column match values in another column
Which of the following SQL commands is used to delete a table's structure and data from a database?
a. TRUNCATE
b. DROP
c. DELETE
d. REMOVE
Answer: b. DROP
What is the purpose of the SELECT DISTINCT statement in SQL?
a. To update records in a table
b. To retrieve only unique values from a column
c. To insert new records into a table
d. To create a new table
Answer: b. To retrieve only unique values from a column
In a relational database, what is a primary key constraint used for?
a. To enforce data integrity by ensuring that values in one column match values in another column
b. To automatically generate unique identifiers for records
c. To define the data type of a column
d. To create indexes for fast data retrieval
Answer: b. To automatically generate unique identifiers for records
Which SQL command is used to combine rows from two or more tables based on a related column between them?
a. SELECT
b. JOIN
c. MERGE
d. APPEND
Answer: b. JOIN
What is the purpose of the ORDER BY clause in SQL?
a. To filter rows based on a condition
b. To group rows by a specific column
c. To specify the columns to be selected in a query
d. To sort the result set in ascending or descending order
Answer: d. To sort the result set in ascending or descending order
Which SQL command is used to add a new row of data to a table?
a. SELECT
b. UPDATE
c. INSERT
d. DELETE
Answer: c. INSERT
What is a database transaction?
a. A database schema
b. A sequence of SQL commands
c. A group of related database operations that are treated as a single unit
d. A database query
Answer: c. A group of related database operations that are treated as a single unit
Which of the following is NOT a type of database model?
a. Relational
b. Object-Oriented
c. Hierarchical
d. Distributed
Answer: d. Distributed
In a relational database, what is a view?
a. A type of database schema
b. A temporary table that stores query results
c. A way to hide sensitive data from users
d. A data type
Answer: b. A temporary table that stores query results
What is the purpose of the WHERE clause in an SQL DELETE statement?
a. To specify the columns to be deleted
b. To specify the order of the result set
c. To filter rows to be deleted based on a condition
d. To group rows by a specific column
Answer: c. To filter rows to be deleted based on a condition
Which SQL command is used to change data in a table?
a. ALTER
b. DELETE
c. UPDATE
d. INSERT
Answer: c. UPDATE
In a relational database, what is a schema?
a. A database user
b. A sequence of SQL statements
c. A collection of database objects (tables, views, etc.) organized by a user
d. A data type
Answer: c. A collection of database objects (tables, views, etc.) organized by a user
Which of the following is a benefit of using a stored procedure in a database?
a. Improved data retrieval performance
b. Reduced data redundancy
c. Easier data modeling
d. Code reusability and security
Answer: d. Code reusability and security
In the context of database transactions, what does ACID stand for?
a. Atomicity, Concurrency, Integrity, Durability
b. Association, Compatibility, Integration, Decryption
c. Allocation, Configuration, Inversion, Deletion
d. Accumulation, Control, Inheritance, Design
Answer: a. Atomicity, Concurrency, Integrity, Durability
Which of the following is a type of SQL constraint that enforces uniqueness for values in a column or set of columns?
a. PRIMARY KEY constraint
b. FOREIGN KEY constraint
c. UNIQUE constraint
d. CHECK constraint
Answer: c. UNIQUE constraint
What is the purpose of the GROUP BY clause in SQL?
a. To order the result set in ascending order
b. To filter rows based on a condition
c. To group rows by a specific column for aggregation
d. To create a temporary table
Answer: c. To group rows by a specific column for aggregation
In a relational database, what does a "one-to-many" relationship between two tables mean?
a. Each row in the first table corresponds to one row in the second table.
b. Each row in the second table corresponds to one row in the first table.
c. Many rows in the first table can correspond to many rows in the second table.
d. Each row in the first table corresponds to many rows in the second table.
Answer: b. Each row in the second table corresponds to one row in the first table.
What is the purpose of the INDEX in a database?
a. To store large binary files
b. To enforce data integrity constraints
c. To improve data retrieval performance
d. To perform mathematical calculations
Answer: c. To improve data retrieval performance
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