Subset and Superset

Beyond combining sets, you often need to check if one set is contained within another. These containment relationships are called subset and superset. A subset is a set where every element exists in another larger set. A superset is the opposite: it contains all elements of a smaller set plus possibly more. Subset and superset checks are fundamental for validation, permission checking, and hierarchical data. For example, checking if a user has required permissions (user permissions should be a superset of required permissions), or validating that input is within allowed values (input should be a subset of allowed values). The permission sets form a hierarchy: basic is a subset of editor, which is a subset of admin. This reflects the real permission structure where higher roles include all

About This Interactive Section

This section is part of the Sets: Intermediate lesson on DataDriven, a free data engineering interview prep platform. Each section includes explanations, worked examples, and hands-on code challenges that execute in real time. SQL queries run against a live PostgreSQL database. Python runs in a sandboxed Docker container. Data modeling problems validate against interactive schema canvases. All content is framed around what data engineering interviewers actually test at companies like Meta, Google, Amazon, Netflix, Stripe, and Databricks.

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DataDriven combines four interview rounds (SQL, Python, Data Modeling, Pipeline Architecture) with adaptive difficulty and spaced repetition. Easy problems get harder as you improve. Weak concepts resurface until you master them. Your readiness score tracks progress across every topic interviewers test. Every lesson section ends with problems you solve by writing and running real code, not by picking multiple-choice answers.