ClickHouse DBA Support Archives

ClickHouse Performance Settings in 26.8 LTS: 14 Proven Changes

The ClickHouse performance settings that changed between 26.3 LTS and 26.8 LTS: what each default does to ingest, aggregation, joins and distributed execution, how to measure it, and the rollout method we use.

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ClickHouse Troubleshooting Techniques: 8 Proven Drills We Teach

ChistaDATA Inc.

The ClickHouse troubleshooting techniques taught in CHT-400 at ChistaDATA University: a scope, prove, fix method and the diagnostic queries for eight production incidents, from too many parts to distributed timeouts.

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ClickHouse certification and competency ladder at ChistaDATA University: CHT-100 to CHT-300 core levels, CHT-400 and CHT-500 specialist programmes, CHT-900 executive track, and the three certification tiers

ClickHouse Certification at ChistaDATA University: 3 Proven Tiers

ChistaDATA Inc.

How ChistaDATA University builds ClickHouse certification on a competency ladder: CHT-100 to CHT-900 programmes, real lab code, failure drills, a live-cluster capstone defence, corporate and academic delivery, and how to start.

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ClickHouse Upgrade Guide: 6 Proven Steps for Zero-Downtime Rolling LTS Upgrades

ChistaDATA Inc.

A production ClickHouse upgrade done properly is a rolling, replica-by-replica operation with zero query downtime, a measured before/after regression check, and a rollback posture decided before the first package is installed. Done casually, it is […]

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

ChistaDATA Inc.

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 […]

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 Query Performance Tuning: A Production Diagnostic Playbook

ChistaDATA Inc.

Effective ClickHouse query performance tuning is less about magic settings and more about a repeatable diagnostic loop: measure, read the plan, isolate the bottleneck, change one variable, and re-measure. This playbook is written for senior […]

ClickHouse Performance Observability and Monitoring: A Complete Whitepaper

ChistaDATA Inc.

ClickHouse performance observability and monitoring is the discipline of measuring, visualizing, and continuously improving how a ClickHouse cluster behaves under real-world workloads. As organizations adopt ClickHouse to power sub-second analytics over petabyte-scale datasets, the gap […]

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 […]

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