Interview Guides
You are given Salesforce CRM lead records with missing values in owner, region, and lead source fields. Write a PostgreSQL query that prepares the data for analysis by returning one cleaned row per lead created in January 2024. Use the assigned owner when available, otherwise fall back to the queue owner; standardize missing region and lead_source values into explicit labels; and classify each lead as ready_for_analysis only when both email and annual revenue are present.
