What is the purpose of a database trigger? a) To automatically execute a predefined action in response to certain events b) To create a backup of the database c) To monitor user access to the database d) To restrict access to specific rows in a table Answer: a) To automatically execute a predefined action in […]
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What is a deadlock in a database system? a) A situation where two or more transactions are waiting for each other to release resources b) A state where all transactions are completed successfully c) A technique to backup the database d) A method of recovering from system failure Answer: a) A situation where two or
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What does the term “query optimization” refer to in a DBMS? a) The process of improving the speed and efficiency of a query b) The process of securing a database c) The process of converting queries to indexes d) The process of normalizing a database Answer: a) The process of improving the speed and efficiency
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What does the term “schema” refer to in a database? a) The structure of a database, including tables, columns, and relationships b) The data stored within the tables c) The SQL queries used to interact with the database d) The users who have access to the database Answer: a) The structure of a database, including
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What is a foreign key constraint? a) It ensures that the values in a column match values in a related table b) It ensures that a column does not have null values c) It guarantees the uniqueness of data in a column d) It limits the length of data in a column Answer: a) It
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What does the DISTINCT keyword do in an SQL query? a) It removes duplicate rows from the result set b) It selects only the first row of the result set c) It selects only rows with null values d) It combines rows with similar values Answer: a) It removes duplicate rows from the result set
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What is the purpose of the JOIN clause in SQL? a) To combine rows from two or more tables based on a related column b) To filter records based on conditions c) To delete rows from a table d) To insert new rows into a table Answer: a) To combine rows from two or more
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What does the ACID acronym stand for in database transactions? a) Accuracy, Concurrency, Isolation, Durability b) Atomicity, Consistency, Isolation, Durability c) Accuracy, Consistency, Independence, Data Integrity d) Authentication, Control, Integrity, Data Management Answer: b) Atomicity, Consistency, Isolation, Durability Explanation: ACID stands for Atomicity, Consistency, Isolation, and Durability. These are the key properties that guarantee reliable
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Which of the following is an aggregate function in SQL? a) COUNT() b) INSERT() c) DELETE() d) ALTER() Answer: a) COUNT() Explanation: COUNT() is an aggregate function in SQL that returns the number of rows that match a specified condition. It is commonly used to count rows in a table or the number of non-null
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Which SQL clause is used to filter records in a query? a) SELECT b) WHERE c) ORDER BY d) GROUP BY Answer: b) WHERE Explanation: The WHERE clause is used in SQL queries to filter records based on specific conditions. It limits the rows returned by the query to those that meet the specified condition.
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What is a transaction in a database? a) A group of SQL statements that must be executed as a single unit b) A single SQL query to retrieve data c) A record of changes made to the database d) A copy of the database Answer: a) A group of SQL statements that must be executed
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What is a view in a database? a) A virtual table based on the result of a SELECT query b) A physical table that stores duplicate data c) A backup of the database d) A key that links two tables together Answer: a) A virtual table based on the result of a SELECT query Explanation:
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What is an index in a database? a) A structure that improves the speed of data retrieval b) A column used to store primary keys c) A table used to track database transactions d) A temporary copy of the database Answer: a) A structure that improves the speed of data retrieval Explanation: An index is
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What is denormalization in a database? a) The process of combining normalized tables to improve performance b) The process of deleting redundant data from tables c) The process of normalizing a database d) The process of optimizing the indexing structure Answer: a) The process of combining normalized tables to improve performance Explanation: Denormalization is the
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What is normalization in a database? a) Organizing data to reduce redundancy and improve data integrity b) Duplicating data across multiple tables for faster access c) Increasing the number of tables in the database d) Compressing data to save storage space Answer: a) Organizing data to reduce redundancy and improve data integrity Explanation: Normalization is
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What is the purpose of a foreign key in a relational database? a) To ensure that each row is unique in the table b) To establish a relationship between two tables c) To speed up query performance d) To store large objects Answer: b) To establish a relationship between two tables Explanation: A foreign key
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What is a primary key in a relational database? a) A key that uniquely identifies each row in a table b) A key that allows duplicate values in a column c) A key that is used to link two tables d) A key that stores null values Answer: a) A key that uniquely identifies each
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Which of the following is an example of a relational database management system (RDBMS)? a) MongoDB b) MySQL c) Redis d) Cassandra Answer: b) MySQL Explanation: MySQL is an example of a relational database management system (RDBMS), which stores data in the form of tables. In an RDBMS, data is organized based on relationships between
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What does SQL stand for? a) Structured Query Language b) Sequential Query Logic c) Simple Query Language d) Structured Query Logic Answer: a) Structured Query Language Explanation: SQL stands for Structured Query Language. It is the standard language used for managing and manipulating databases. SQL allows users to perform operations such as querying, updating, inserting,
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What is a database management system (DBMS)? a) A software system that allows users to store, retrieve, and manipulate data in a database b) A collection of data organized in a specific format c) A hardware device to store data d) An application used to browse the web Answer: a) A software system that allows
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What is “port forwarding” in networking? a) A technique used to allow external devices to access services on a private network b) A method for encrypting network traffic c) A way to assign dynamic IP addresses d) A tool for monitoring bandwidth usage Answer: a) A technique used to allow external devices to access services
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What is “ARP” (Address Resolution Protocol) used for in networking? a) To map an IP address to a MAC address b) To assign IP addresses to devices c) To encrypt data packets d) To monitor network traffic Answer: a) To map an IP address to a MAC address Explanation: ARP (Address Resolution Protocol) is a
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What is the purpose of “QoS” (Quality of Service) in networking? a) To prioritize certain types of network traffic for better performance b) To assign IP addresses automatically c) To compress data for faster transmission d) To encrypt data for security Answer: a) To prioritize certain types of network traffic for better performance Explanation: Quality
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What is a “router” in networking? a) A device that directs data packets between different networks b) A device used to encrypt data c) A tool for monitoring network bandwidth d) A method for compressing data Answer: a) A device that directs data packets between different networks Explanation: A router is a networking device that
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What is “NAT traversal” in networking? a) A technique used to establish connections across devices behind a NAT router b) A method for assigning IP addresses c) A protocol for encrypting data packets d) A tool for monitoring network performance Answer: a) A technique used to establish connections across devices behind a NAT router Explanation:
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