ClickHouse Tips Archives | Page 2 of 2

ClickHouse Performance: Estimated & Actual Row Counts in Execution Plans

PREWHERE vs WHERE in ClickHouse Queries

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

ChistaDATA Inc.

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

ChistaDATA Inc.

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 […]

How Regular Expressions Are Implemented in ClickHouse

ClickHouse ReplacingMergeTree Explained

ChistaDATA Inc.

ClickHouse ReplacingMergeTree Introduction ClickHouse ReplacingMergeTree is a powerful table engine designed to handle data deduplication in analytical workloads. While it promises to solve duplicate data challenges, understanding its nuances is crucial for successful implementation. This […]

Troubleshooting Suboptimal ClickHouse Queries

Shiv Iyer

ClickHouse Queries To troubleshoot and optimize slow ClickHouse queries, follow these steps: 1. Use EXPLAIN to Analyze Query Plans EXPLAIN syntax SELECT * FROM table WHERE condition Available syntax options: EXPLAIN PLAN – shows execution […]

Data Security and Data Masking in ClickHouse

Shiv Iyer

Comprehensive Guide to Data Security and Data Masking in ClickHouse: Protecting Your Data While Maintaining Performance In today’s data-driven landscape, organizations face the dual challenge of leveraging their data for insights while ensuring robust protection […]

How do you query large quantities of data optimally in ClickHouse?

Shiv Iyer

ClickHouse Query Optimisation for Large Datasets This comprehensive guide explores advanced techniques for optimising queries in ClickHouse when working with large-scale datasets. ClickHouse is a powerful columnar database management system designed for online analytical processing […]

Most Common ClickHouse Analytical Models

Shiv Iyer

Unlocking ClickHouse’s Potential: A Deep Dive into the Most Common Analytical Models ClickHouse is a high-performance, columnar database management system designed for real-time analytical workloads. Its architecture allows it to process large datasets at lightning […]

ClickHouse as Archival Store to boost PostgreSQL & MySQL Performance

Shiv Iyer

Introduction ClickHouse is a versatile database management system known for its real-time analytics capabilities. However, it offers more than just real-time analytics. ClickHouse can also serve as an archive store for transaction computing systems or […]