Interview Questions and Answers
Freshers / Beginner level questions & answers
Ques 1. Explain the concept of ACID properties in the context of databases.
ACID stands for Atomicity, Consistency, Isolation, and Durability, ensuring the reliability of database transactions.
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Ques 2. What is the purpose of the WHERE clause in a PostgreSQL query?
The WHERE clause filters records based on a specified condition, allowing selective data retrieval.
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Ques 3. What is a foreign key, and how does it enforce referential integrity?
A foreign key is a field that refers to the primary key in another table. It enforces referential integrity by ensuring that values in the foreign key match values in the referenced table's primary key.
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Ques 4. Explain the purpose of the SERIAL data type in PostgreSQL.
SERIAL is an auto-incrementing integer data type often used for creating unique identifiers in a column. It is commonly used for primary key columns.
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Ques 5. What is the purpose of the pg_ctl utility in PostgreSQL?
The pg_ctl utility is used to start, stop, and control the PostgreSQL server, providing a convenient way to manage server processes.
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Ques 6. What is the purpose of the pg_dumpall utility in PostgreSQL?
The pg_dumpall utility is used to create a SQL script that can reconstruct an entire PostgreSQL database cluster, including all databases, users, and privileges.
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Most helpful rated by users:
- Explain the concept of ACID properties in the context of databases.
- What is the purpose of the WHERE clause in a PostgreSQL query?
- What is a foreign key, and how does it enforce referential integrity?
- Explain the purpose of the SERIAL data type in PostgreSQL.