First-Day Session Retention

A hard SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

hard

Seniority

mid, senior

Problem

A user is 'retained' if they have a session exactly 1 calendar day after their very first session. Calculate the proportion of retained users out of all users. Return a single retention rate.

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a live PostgreSQL database and grades it instantly.