Design and review production database schemas, data models, ERDs, migration plans, and storage patterns. Use for OLTP schema design, OLAP/star-schema modeling, fact/dimension tables, indexes, constraints, partitioning, multi-tenant data models, CSV/JSON-to-table design, schema review, migration risk review, and database design documents across PostgreSQL, MySQL, SQLite/D1, BigQuery, and MongoDB. Does not execute DDL by default.
