Stream Processing vs. Incremental Computing: Picking the Right Tool for Real-Time Data Challenges
Oct 27,2025
In my previous piece, we explored why traditional batch processing falls short in today’s fast-paced world—such as detecting fraud in finance before it’s too late or maintaining real-time e-commerce stock levels. Batch jobs accumulate data and process it in batches, which can increase latency and consume excessive resources. Enter incremental computing: it zeroes in on just the deltas, dropping delays to mere milliseconds while slashing resource demands by 90% or more.
— Users stream
CREATE TABLE users ( user_id BIGINT, user_name STRING, user_level STRING, country STRING, city STRING, signup_time TIMESTAMP(3), WATERMARK FOR signup_time AS signup_time – INTERVAL ’10’ SECOND ) WITH ( ‘connector’ = ‘kafka’, ‘topic’ = ‘users’, ‘properties.bootstrap.servers’ = ‘localhost:9092’, ‘format’ = ‘json’ );
— Orders stream
CREATE TABLE orders ( order_id BIGINT, user_id BIGINT, order_status STRING, order_amount DECIMAL(10,2), payment_method STRING, order_time TIMESTAMP(3), WATERMARK FOR order_time AS order_time – INTERVAL ’10’ SECOND ) WITH ( ‘connector’ = ‘kafka’, ‘topic’ = ‘orders’, ‘properties.bootstrap.servers’ = ‘localhost:9092’, ‘format’ = ‘json’ );
— Merged view via JOIN
CREATE VIEW unified_view AS SELECT o.order_id, o.user_id, u.user_name, u.user_level, u.country, u.city, u.signup_time, o.order_status, o.order_amount, o.payment_method, o.order_time FROM orders o LEFT JOIN users FOR SYSTEM_TIME AS OF o.order_time AS u ON o.user_id = u.user_id;
— Export downstream (Kafka/DB) or aggregate
INSERT INTO output_kafka
SELECT * FROM unified_view;
— For corrections or backfills (e.g., fixing a missed event), this might require expensive full stream replays, as partial updates aren’t natively supported without custom logic.

 

This is for illustration only—actual production use may need extensive tuning for your specific setup.
Challenges: This example demonstrates foundational setup but underscores the roadblocks when applied to real-world scenarios. Beyond connector overhead (e.g., extending this to non-Kafka sources like MongoDB would need custom code), expect window size trade-offs (accuracy vs. speed) as seen in the watermark intervals—too short, and you miss events; too long, and latency spikes. Watermark adjustments for out-of-order events are evident in the table definitions, but in peak e-commerce loads, they demand constant monitoring to prevent data mismatches.
Expensive full stream replays for corrections become apparent in the export step, where fixing errors often means reprocessing everything rather than deltas. Throughput bottlenecks during peak loads and memory spikes from complex joins (like the temporal join here) can escalate quickly in multi-stream environments, turning a simple script into an ops-heavy beast. For more on Flink, check their docs.
The Incremental Computing Route
Tools like Materialize.io allow you to declare materialized views in SQL, with automatic incremental updates handled internally. Platforms like TapData provide visual interfaces: drag-and-drop joins across sources, detect changes, and output results (e.g., to MongoDB)—all with efficient memory usage.
Visualize linking users and orders into a denormalized table, piped to storage:

 

Post-launch, metrics like RPS and lag pop up in dashboards for at-a-glance health checks.
These views double as APIs for instant querying, and outputs chain into further processing—closing the loop from ingestion to deployment.

Incremental Computing’s Edge in Action

This comparison highlights why incremental computing often prevails: Native support for dozens of data sources significantly reduces setup time, compared to stream processing’s custom integrations.
  • Lower Learning Curve: Work with familiar tables and SQL—no complex timing concepts required.
  • Strong Consistency: CDC captures every change accurately, avoiding stream processing artifacts.
  • Efficient Resource Usage: Delta-only processing reduces overhead; durable views outperform volatile states.
  • Computational Reuse: Share computations across multiple queries for enhanced efficiency.

Final Thoughts

Both approaches shine in their own domains: stream processing for handling high-speed raw events and real-time monitoring; incremental computing for delivering refined, enterprise-grade reliability and polish.
As real-time needs surge, paths split: streams for niche events, incremental for broad analytics value. For typical teams, platforms like TapData deliver a no-nonsense upgrade with robust CDC, wide connector support, and easy API exposure—paving a sustainable real-time road.
No silver bullets in tech—align with your ops and crew. Weighing real-time options? Share your scenario below for tailored takes!

 

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