Context

In SQL interviews, candidates are often asked how they would analyze a new dataset before writing complex queries. Interviewers want to see whether you can move from raw tables to reliable insights in a structured way.

Core question

Explain how you would approach analyzing a dataset using SQL. Your answer should cover:

1. How you inspect the table structure and understand the available fields
2. How you check data quality issues such as NULLs, duplicates, and unexpected values
3. How you summarize the data with basic aggregations and grouping
4. How you decide what follow-up queries to run based on early findings

Scope guidance

Keep the answer practical and SQL-oriented. The interviewer is not looking for advanced modeling or machine learning. Focus on a clear, step-by-step workflow for exploring, validating, and summarizing data in PostgreSQL, and mention the kinds of queries you would write at each stage.