ClickHouse: Open-source column-oriented analytical database

-- Create analytics events table
CREATE TABLE analytics.events (
    event_id UUID DEFAULT generateUUIDv4(),
    user_id UInt64,
    event_type LowCardinality(String),
    timestamp DateTime64(3) DEFAULT now64(),
    properties Map(String, String),
    session_id String,
    page_url String,
    user_agent String
) ENGINE = MergeTree()
PARTITION BY toYYYYMM(timestamp)
ORDER BY (event_type, timestamp, user_id);

-- Query for real-time analytics dashboard
SELECT 
    event_type,
    count() as event_count,
    uniq(user_id) as unique_users,
    avg(toUnixTimestamp(timestamp)) as avg_timestamp
FROM analytics.events 
WHERE timestamp >= now() - INTERVAL 1 HOUR
GROUP BY event_type
ORDER BY event_count DESC;