ClickHouse Performance Tuning Archives

ChistaDATA Performance

ClickHouse Performance Audit: 8 Best Tips for 26.8 LTS

ClickHouse performance audit tips for 26.8 LTS with real lab output: rank query shapes in system.query_log, measure cold past the query condition cache, read EXPLAIN ANALYZE and EXPLAIN WHATIF, and audit codecs per block.

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Real-Time Analytics on ClickHouse 26.8: 6 Proven Levers

ChistaDATA Inc.

Real-time analytics on ClickHouse 26.8: the ingest-to-dashboard latency budget, async-insert freshness, top-K and cache serving, lightweight UPDATE, and ingest/serving isolation on self-managed clusters versus ClickHouse Cloud.

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ClickHouse 26.8 LTS: 7 Essential Performance and HA Changes

ChistaDATA Inc.

ClickHouse 26.8 LTS read for production: adaptive aggregation, IEJoin, plan-based parallel replicas, Keeper on disk, always_fetch_mutated_part, and the 26.3 to 26.8 breaking-change checklist for self-managed and Cloud.

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ClickHouse 26.8 LTS: What’s New for Real-Time Analytics (Tested)

ChistaDATA Inc.

ClickHouse 26.8 shipped on 27 August 2026 as the second LTS line of the year, and two days later the 25.8 LTS line dropped out of support. If you run 25.8 in production, you are […]

ClickHouse Sharding Troubleshooting and Performance Optimization

ChistaDATA Inc.

A field guide to ClickHouse sharding troubleshooting: Distributed send-queue backlogs, duplicate rows from internal_replication, shard skew, initiator merge bottlenecks, distributed JOIN failures and unavailable shards, each with the system.* evidence, the mechanism, the staged fix, and the alert that catches it early.

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Troubleshooting ClickHouse high CPU usage with the sampling profiler, system.trace_log stacks and flamegraphs

Troubleshooting High CPU Usage in ClickHouse: From system.trace_log to Flamegraphs

ChistaDATA Inc.

Diagnose ClickHouse high CPU usage with the sampling profiler, system.trace_log stacks, and flamegraphs, plus the five hotspots we see most often.

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ClickHouse

Using EXPLAIN PIPELINE to Decode ClickHouse Query Execution Bottlenecks

ChistaDATA Inc.

Learn to read ClickHouse EXPLAIN PIPELINE processor graphs, spot single-threaded stages and pipeline stalls, and fix production bottlenecks.

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ClickHouse slow query troubleshooting: diagnosing query latency with system.query_log, a ChistaDATA production methodology

Diagnosing Slow ClickHouse Queries with system.query_log: A Production Methodology

ChistaDATA Inc.

Master ClickHouse slow query troubleshooting with a production-proven system.query_log methodology to find, classify, and fix query latency fast.

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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, […]

Scaling ClickHouse from Gigabytes to Petabytes: A Practical Playbook

ChistaDATA Inc.

Most teams don’t run into ClickHouse scaling challenges when they’re managing a few hundred gigabytes. The problems surface the moment data volumes cross a threshold where naive configurations begin to crack — queries slow down, […]