ClickHouse Tips Archives | ChistaDATA Inc.

Using system.query_thread_log for Low-Level ClickHouse Performance Insights

Using system.query_thread_log in ClickHouse for Low-Level Performance Insights Introduction to Thread-Level Query Analysis In the realm of high-performance analytical databases, ClickHouse stands out for its ability to process massive datasets at lightning speed. However, as […]

Troubleshooting ClickHouse in Kubernetes

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Introduction: Troubleshooting ClickHouse in Kubernetes This knowledge base provides a foundational guide for administrators and developers to troubleshoot ClickHouse instances running on Kubernetes pods within an AWS EKS environment. By following these steps, users can […]

ClickHouse Complete Guide to LowCardinality

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ClickHouse Complete Guide to LowCardinality: When and How to Use It Introduction ClickHouse, the high-performance columnar database management system, offers a specialized data type called LowCardinality that serves as a powerful optimization tool for specific […]

ClickHouse Storage Tiering Best Practices: Moving Data Between Hot and Cold Storage with TTL

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ClickHouse Storage Tiering Best Practices: Moving Data Between Hot and Cold Storage with TTL Efficient data management is critical for modern analytical databases, especially when dealing with large volumes of time-series or event-driven data. ClickHouse, […]

Overview of Vectorized Query Processing in ClickHouse

Troubleshooting Disk Space in ClickHouse

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Troubleshooting Disk Space Issues: Managing ClickHouse Log Tables ClickHouse is a high-performance, columnar database management system optimized for real-time analytical workloads. While its speed and scalability make it ideal for large-scale data processing, one common […]

ClickHouse Search: Case-sensitive Searches with UPPER & LOWER Functions

Boosting Materialized View Performance

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Aggregation States: Boosting Materialized View Performance by 10x in ClickHouse ClickHouse has long been celebrated for its lightning-fast analytical query performance, especially when handling massive datasets in real time. One of the most powerful features […]

ClickHouse Performance: Estimated & Actual Row Counts in Execution Plans

PREWHERE vs WHERE in ClickHouse Queries

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PREWHERE vs WHERE: When and How to Optimize Your ClickHouse Queries Introduction Query performance in ClickHouse often hinges on how efficiently you filter data. While most SQL users are familiar with the WHERE clause, ClickHouse […]

Tuning index_granularity for ClickHouse Performance

Understanding ClickHouse Wait Events

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Understanding ClickHouse Wait Events: A Comprehensive Troubleshooting Guide Introduction Wait events in ClickHouse reveal where query execution slows down—whether from disk bottlenecks, lock contention, CPU saturation, or network latency. Mastering these signals empowers you to […]

Using EXPLAIN to Determine JOIN Order in ClickHouse Query Execution Plan

Reduce Query Memory Usage in ClickHouse

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How to Reduce Query Memory Usage in ClickHouse: Troubleshooting Memory Limit Exceeded Errors Memory limit exceeded errors are among the most common challenges ClickHouse users face when running complex analytical queries. Whether you’re performing large […]

Troubleshooting Underutilized ClickHouse Index

Unlock Blistering Query Speed with ClickHouse LowCardinality

ChistaDATA Inc.

Unlock Blistering Query Speed with ClickHouse LowCardinality: A ChistaDATA Guide ClickHouse is famous for raw speed, but some of its most powerful tools remain under-documented. Among them, the LowCardinality data type is arguably the simplest […]