sql-review-agent

Please review the following BigQuery SQL, identify performance bottlenecks and possible full table scan issues, and provide rewrite suggestions with reasons: SELECT user_id, COUNT(*) FROM `project.dataset.events` WHERE DATE(event_time) >= '2024-01-01' GROUP BY user_id ORDER BY COUNT(*) DESC LIMIT 100;

Returns performance findings, explanations of inefficient patterns, and a more efficient rewritten SQL query.

Please evaluate the approximate scanned data volume and cost risk of this BigQuery query, and explain which filters or partition conditions could reduce cost: SELECT * FROM `project.dataset.orders` WHERE customer_region = 'APAC' AND status = 'paid';

Returns a cost risk assessment, rationale for scan estimates, and suggestions to reduce query cost.

Please rewrite this BigQuery SQL into a production-friendly version, prioritizing partition pruning, reducing scanned columns, and readability, and list the changes made: SELECT * FROM `project.dataset.sessions` WHERE EXTRACT(YEAR FROM session_start)=2024 AND country IN ('US','CA');

Returns optimized SQL, a change-by-change explanation, and the expected performance improvement direction.