Indexing and Query Performance | Dataford Interview Questions

Explain the importance of indexing in databases.

Use the provided PostgreSQL tickets table to demonstrate a selective lookup. Write a query that returns open tickets created on or after January 1, 2025, and briefly explain how an appropriate index could improve this query.

Output

One row per matching ticket with columns ticket_id, status, priority, and created_at
Exclude tickets that are not open or were created before the specified date
Sort by newest created_at first, then ticket_id ascending

Schema

tickets

Column	Type	Description
ticket_idPK	INT	Unique ticket identifier
status	VARCHAR(20)	Current ticket status
priority	VARCHAR(20)	Ticket priority
created_at	DATE	Date the ticket was created

Your question is Indexing and Query Performance. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Explain the importance of indexing in databases.

Output

One row per matching ticket with columns ticket_id, status, priority, and created_at
Exclude tickets that are not open or were created before the specified date
Sort by newest created_at first, then ticket_id ascending

Schema

tickets

Column	Type	Description
ticket_idPK	INT	Unique ticket identifier
status	VARCHAR(20)	Current ticket status
priority	VARCHAR(20)	Ticket priority
created_at	DATE	Date the ticket was created

Your question is Indexing and Query Performance. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.