What is PostgreSQL - Practice Questions & Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is PostgreSQL primarily used for?

Choose the best description of PostgreSQL's main purpose.

A A relational database management system to store and manage data.

B A web server software to host websites.

C A programming language for building mobile apps.

D A tool for graphic design and image editing.

💡 Hint

Think about where data is stored and organized for applications.

PostgreSQL is a powerful system designed to store, organize, and retrieve data efficiently.

🧠 Conceptual

intermediate

Which feature is a key strength of PostgreSQL?

Select the feature that best describes PostgreSQL's capabilities.

A Is mainly used for video editing and rendering.

B Only stores data in simple text files without structure.

C Runs only on Windows operating systems.

D Supports complex queries and transactions with data integrity.

💡 Hint

Think about how databases handle multiple operations safely.

PostgreSQL supports complex queries and ensures data integrity through transactions.

❓ query_result

advanced

What is the output of this PostgreSQL query?

Given the table 'employees' with columns 'id' and 'name', what does this query return?

SELECT COUNT(*) FROM employees WHERE name LIKE 'A%';

PostgreSQL

SELECT COUNT(*) FROM employees WHERE name LIKE 'A%';

A The total number of employees in the table.

B The number of employees whose names start with 'A'.

C An error because LIKE cannot be used with COUNT.

D A list of employee names starting with 'A'.

💡 Hint

COUNT(*) counts rows matching the condition.

The query counts how many employees have names starting with 'A'.

📝 Syntax

advanced

Which option is a valid PostgreSQL command to create a table?

Identify the correct SQL syntax to create a table named 'products' with columns 'id' (integer) and 'name' (text).

A CREATE products TABLE (id INTEGER, name TEXT);

B MAKE TABLE products {id INTEGER, name STRING};

C CREATE TABLE products (id INT, name TEXT);

D TABLE CREATE products (id INT, name TEXT);

💡 Hint

The command starts with CREATE TABLE followed by table name and columns.

Option C uses correct PostgreSQL syntax for creating a table.

❓ optimization

expert

Which index type is best for speeding up text search in PostgreSQL?

You want to optimize searches for words inside large text columns. Which index type should you use?

A GIN (Generalized Inverted Index)

B Hash index

C B-tree index

D Bitmap index

💡 Hint

Think about indexes designed for full-text search.

GIN indexes are optimized for searching within text and arrays efficiently.