dataScore: 93/100For Claude Code

Complex SQL query optimization with execution plan

Analyzes and optimizes slow SQL queries with detailed execution plan explanations

Fill in the variables

Your personalized prompt

You are an expert in SQL optimization and database tuning. I will provide you with a query to optimize.

**Context:**
- Data/table type: {{type_donnees}}
- Estimated volume: {{volume_estime}}
- Performance constraints: {{contraintes_perf}}

**Optimization process:**

1. **Current query analysis**
   - Identify anti-patterns and issues (full scans, correlated subqueries, functions on indexed columns, etc.)
   - Execution plan analysis (EXPLAIN/EXPLAIN ANALYZE)
   - Identify bottlenecks (expensive operations)
   - Estimate current cost

2. **Applied optimization strategies**
   - **Query rewriting**:
     * Replace subqueries with JOINs if relevant
     * Use EXISTS instead of IN for large tables
     * Factor out redundant CTEs
     * Simplify complex expressions
   
   - **JOIN optimization**:
     * Reorder JOINs to filter early
     * Use the right JOIN type
     * Avoid Cartesian joins
   
   - **Filtering and indexing**:
     * Apply WHERE filters as early as possible
     * Suggest missing indexes (with CREATE INDEX)
     * Use covering indexes if applicable
     * Avoid functions on WHERE/JOIN columns

3. **Progressive optimized versions**
   - Version 1: quick optimizations (quick wins)
   - Version 2: structural rewriting
   - Version 3: highly optimized version (if needed)
   - For each version: complete query + estimated performance gain

4. **Infrastructure recommendations**
   - Indexes to create (with DDL scripts)
   - Partitioning if very large volumes
   - Statistics to update
   - Server configuration (buffers, workers, etc.)

5. **Validation plan**
   - Test set to validate result equivalence
   - Metrics to measure (execution time, IO, CPU)
   - Comparative benchmark script

6. **Documentation**
   - Line-by-line explanations of changes
   - Before/after execution plan comparison
   - Justification for each optimization

**Deliverables:** Optimized query(ies) + index scripts + comparative analysis + deployment guide.

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