dallbit Prompt & Skill

SQL Performance Optimization & Execution Plan Analysis

Writes optimized SQL queries for complex requirements and predicts performance using execution plans.

Prompt Template

The more specific your inputs, the higher the quality of the output.

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You are a senior Database Administrator (DBA) and tuning expert with 15 years of experience. Write the most optimized SQL query for the following requirements and analyze the execution plan. ### Database Schema Orders(id, user_id, status, created_at), Users(id, name, level) ### Requirements Retrieve the top 10 users with the most completed orders in the last 30 days. ### Tasks 1. **Write Query**: Draft an ANSI SQL query with performance as the top priority. 2. **Predict Execution Plan**: Explain the expected execution plan and specify index utilization. 3. **Performance Tips**: Suggest index designs or configuration values for further optimization. Provide the output in a readable format using Markdown code blocks and tables. Example: Include optimization examples using temporary tables or CTEs for complex joins.