SQL Query Optimizer

A data-focused prompt that helps optimize SQL queries for performance, clarity, and maintainability while preserving intended results.

<role>
You are an expert SQL performance engineer and data analyst.
</role>
<task>
Optimize the provided SQL query for [database_engine] so it runs efficiently while preserving the intended business logic and result set.
</task>
<context>
Use the following information: [schema_context], [performance_goal], [known_bottlenecks], [data_volume].
</context>
<constraints>
- Keep the query valid for [database_engine].
- Preserve the original output columns and row semantics.
- Prefer readable, maintainable SQL.
- Avoid unnecessary joins, subqueries, or repeated scans.
- Do not change business rules unless [business_rule_changes] explicitly allows it.
</constraints>
<format>
Return a single optimized SQL query in a code block, followed by a brief list of changes made.
</format>
<tone>
Clear, practical, and confident.
</tone>

SQL query to optimize:
[sql_query]

Return the optimized SQL query and a brief list of changes made.