ClickHouse Query Optimization

Load when writing, debugging, or optimizing ClickHouse queries.

Goals

• 10-100x faster query execution
• 90%+ reduction in memory usage
• Eliminate full table scans (read <1% of data)
• JOINs that complete in milliseconds instead of minutes

Reference Documentation

• Query Optimization
• PREWHERE
• JOINs
• Dictionaries
• Query Settings