ClickHouse Performance Archives

ClickHouse Ingestion Performance: Batch Sizing, Async Inserts, and Kafka Pipelines

ClickHouse ingestion performance is decided long before the query planner ever touches your data. It is decided by how many parts your writers create per second, how much background merge work those parts generate, and […]

ClickHouse Merge Performance: Diagnosing Too Many Parts, Slow Merges, and Stuck Mutations

ChistaDATA Inc.

ClickHouse merge performance is the hinge on which every high-ingest MergeTree deployment turns. When background merges keep pace with inserts, part counts stay flat and SELECT latency stays predictable. When they fall behind, the failure […]

Scaling ClickHouse Horizontally: Sharding, Distributed Tables, and Parallel Replicas

ChistaDATA Inc.

Horizontal scale is where most ClickHouse fleets accumulate their deepest operational debt. ClickHouse sharding gets introduced months before the workload justifies it, and once a sharding key is baked into a production Distributed table, unwinding […]

ClickHouse MergeTree Optimization: Sort Keys, Partitioning, Skip Indexes, and Projections

ChistaDATA Inc.

ClickHouse MergeTree optimization is the difference between a table that answers analytical queries in milliseconds and one that scans hundreds of gigabytes for every request. This guide is written for senior engineers who already understand […]

ClickHouse IOPS Troubleshooting: A Complete Guide to Diagnosing and Fixing Disk I/O Bottlenecks

ChistaDATA Inc.

NEEDS FEATURED IMAGE. ClickHouse IOPS troubleshooting guide for DBAs and SREs: diagnose disk I/O bottlenecks with ClickHouse system tables, verify at the OS layer with iostat and pidstat, fix merge storms and part explosion, tune caches, tier storage, and monitor IOPS continuously with Prometheus and Grafana.

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ClickHouse Shard Contention Troubleshooting: A Complete Guide

ChistaDATA Inc.

ClickHouse shard contention is one of the most frustrating performance problems a distributed database team can face. When a cluster scales out to dozens or hundreds of nodes, the promise of linear scalability quietly breaks […]

ClickHouse Retail Analytics with Python: A Real-Time Reference Architecture

ChistaDATA Inc.

Retail runs on events. Every scanned item at a point-of-sale terminal, every product view on an e-commerce storefront, every abandoned cart, price change, and inventory adjustment is a discrete signal generated at high velocity. Modern […]

20 Things You Should Not Do With ClickHouse Which Will Destroy ClickHouse Performance

ChistaDATA Inc.

ClickHouse is one of the fastest open source columnar databases for real-time analytics, and it powers observability platforms, product analytics, and large-scale reporting workloads across the industry. Yet raw speed can be deceptive. Many teams […]

7 Powerful ClickHouse Matrices for Troubleshooting Query and IOPS Performance

ChistaDATA Inc.

When a ClickHouse cluster starts feeling sluggish, the hardest part is rarely fixing the problem — it’s finding it. Slow queries, saturated disks, and unpredictable latency all leave fingerprints, but those fingerprints are scattered across […]

How to Run a Complete ClickHouse Performance Audit in Under 60 Minutes

ChistaDATA Inc.

ClickHouse performance audit is the fastest way to uncover hidden bottlenecks, misconfigured settings, and query inefficiencies draining your analytical database. Whether you are running ClickHouse on bare metal, Kubernetes, or as a managed cloud service, […]