Best Practices for Query Optimization in ClickHouse with Spring Boot

November 23, 2025

#1

This guide covers essential techniques to optimize queries in ClickHouse when used with Spring Boot.

1. Use Proper Table Engines

Choose the right engine like MergeTree for large datasets. Define ORDER BY to match your query patterns:

CREATE TABLE events (
    id UInt64,
    user_id UInt32,
    event_time DateTime,
    action String
)
ENGINE = MergeTree()
PARTITION BY toYYYYMM(event_time)
ORDER BY (user_id, event_time);

2. Limit Columns in Queries

Fetch only what you need in Spring Boot:

List<String> actions = jdbcTemplate.queryForList(
    "SELECT action FROM events WHERE user_id = ? LIMIT 100",
    String.class, userId
);

3. Apply Filters Early

Use WHERE clauses to prune partitions:

SELECT count() FROM events 
WHERE event_time >= now() - INTERVAL 7 DAY;

4. Use Batch Inserts

For better performance, insert in batches with Spring Boot:

jdbcTemplate.batchUpdate(
    "INSERT INTO events (id, user_id, event_time, action) VALUES (?, ?, ?, ?)",
    batchArgs
);

5. Profile Queries

Enable system.query_log in ClickHouse to analyze slow queries and adjust schema or indexes.