Make a slow or unreliable SQL report easier to maintain and trust. I will review and optimize one existing query in Snowflake, MySQL, SQL Server, or PostgreSQL while preserving the agreed business logic.

Includes: one query using up to five source tables; corrected SQL; a summary of changes; result-validation checks; and a before/after runtime comparison when a comparable test environment is available. One revision is included.

Please provide the query, schema, expected output, and sample data or approved access. Delivery: within one week after requirements and access are complete.

This package excludes database administration, infrastructure changes, full pipeline redesign, and guaranteed performance improvements. Larger queries can be scoped separately before work begins.