Analyzing Memory Efficiency with Vertical Merges in 26.3
Explore how ClickHouse 26.3 extends Vertical Merge to TTL DELETE operations, reducing memory usage and improving background merge efficiency.
July 24, 20267 min read
Tag: performance
Posts tagged "performance"
Automated Insert Batching in 26.3: Throughput Improvements
Learn how ClickHouse 26.3 improves ingestion throughput with automatic batching for asynchronous inserts, reducing data parts, merge overhead, and CPU usage.
July 22, 20268 min read
Partition Pruning in ClickHouse®: How It Really Works
How ClickHouse's partition pruning skips entire directories of data at query time, when it fails silently, and how to design partition keys correctly
July 21, 20265 min read
EXPLAIN PRETTY and COMPACT in ClickHouse® 26.3
Learn how to visualize ClickHouse® query plans using EXPLAIN pretty=1 and compact=1 in version 26.3 to better understand query execution and optimization.
July 17, 202611 min read
Materialized CTEs in ClickHouse® 26.3: A Performance Benchmark
Benchmark the new Materialized CTE feature in ClickHouse® 26.3 using a reproducible Docker setup, a real dataset, and practical SQL performance tests.
July 14, 202611 min read
Working with ClickHouse® LowCardinality and Enum Types
Learn how to use ClickHouse® LowCardinality and Enum types to optimize storage, improve query performance, and choose the right data type for analytical workloads.
July 11, 20267 min read
ClickHouse® Partitioning at Petabyte Scale
Learn advanced ClickHouse® partitioning strategies for petabyte-scale tables, including partition keys, lifecycle management, and performance optimization.
July 10, 20266 min read
Benchmarking ClickHouse®: Tools & Methodologies
Learn how to benchmark ClickHouse® correctly using industry-standard tools, realistic workloads, and proven methodologies to measure performance accurately.
July 8, 20266 min read
Exploring ClickHouse® System Tables for Troubleshooting
Learn how to use ClickHouse® system tables to monitor server health, analyze queries, track background operations, and troubleshoot performance issues.
June 27, 20266 min read
The ClickHouse® HTTP API: A Beginner’s Overview
New to the ClickHouse® HTTP API? Learn how to query, insert, and manage data using simple HTTP requests - with curl and examples.
June 18, 20268 min read
ClickHouse® for Time-Series Data: A Quick Introduction
Learn how ClickHouse® handles time-series data with fast ingestion, efficient storage, powerful aggregations, and real-time analytics.
June 17, 20269 min read
Basic Data Aggregation in ClickHouse®
Learn the fundamentals of data aggregation in ClickHouse®. Explore aggregate functions, GROUP BY, time-based aggregations, ROLLUP, CUBE, and performance optimiz
June 10, 20267 min read
ClickHouse® Data Types: Explained for Beginners
Explore ClickHouse® data types with real-world examples and learn how to choose the right types for efficient storage and faster queries.
June 9, 202611 min read
ClickHouse® vs PostgreSQL: When to Use Which?
ClickHouse® vs PostgreSQL - what's the real difference? Learn how each database works, when to use which, and its performance trade-offs.
June 4, 20268 min read
Understanding Column-Oriented Databases: The ClickHouse® Advantage
Understand column-oriented databases and explore how ClickHouse® enables faster analytics, better compression, and scalability.
June 4, 20268 min read
Millions of UK House Sales Records, One Interactive Dashboard by ClickHouse® & Apache Superset
Learn how to connect Apache Superset with ClickHouse® to build an interactive UK property analytics dashboard to explore millions of records.
June 2, 20265 min read
Reliable ClickHouse® Backups: From Simple Setups to Production-Ready Strategies
Learn ClickHouse® backup strategies from filesystem approaches to production-ready solutions using clickhouse-backup and native backup.
June 2, 20266 min read
ClickHouse® 26.4 Release: Features, Performance Improvements, and Breaking Changes
Explore ClickHouse® 26.4 features, performance improvements, and breaking changes for production data workloads.
May 23, 20266 min read
Track ClickHouse® Database CPU, Memory, and IO
Use per-second resource timelines to see how a ClickHouse® database query used CPU, memory, and disk IO, and catch the moment it went wrong.
May 16, 20264 min read
Reading ClickHouse® Database Query Flame Graphs
Use the ClickHouse® database query profiler and flame graphs to see exactly where a slow query spends its time, and what to do about it.
May 14, 20264 min read
Debug Slow ClickHouse® Database Queries: System Tables
A practical guide to finding and fixing slow ClickHouse® database queries using system.query_log, system.processes, and the query profiler.
May 12, 20264 min read
When ClickHouse® Queries Are Slow: A Practical Debugging Guide
Struggling with slow ClickHouse® Learn the real reasons behind poor performance and 7 practical fixes to reduce scans and speed up queries.
April 8, 20265 min read
ClickHouse® 26.3 LTS: A Practical Guide to What Changed and Why It Matters
A clear and practical guide to ClickHouse® 26.3 LTS covering key features, performance improvements, breaking changes, and real-world examples for data.
March 28, 20267 min read
ClickHouse® 26.2 Release: Features, Changes & Upgrade Guide
ClickHouse® 26.2 release update covering new features, behavioral changes, performance improvements, and production upgrade guidance.
March 10, 20266 min read
Optimizing ClickHouse® Queries: Adding and Benchmarking Projections
Learn how to optimize ClickHouse® queries by adding and benchmarking projections with before-and-after performance comparisons.
March 10, 20265 min read
Operating ClickHouse® on Kubernetes
Learn why running ClickHouse® on Kubernetes requires the Altinity® Operator, and why StatefulSets alone are not enough for production clusters.
March 10, 20265 min read
Lightweight Delete in ClickHouse®
Learn how Lightweight DELETE works in ClickHouse®, including its internal masking mechanism, background merges, performance trade-offs, limitations, and when to
February 28, 20264 min read
When Should High-Cardinality Columns Come First in ClickHouse® ORDER BY?
Learn when high-cardinality columns improve ClickHouse® ORDER BY performance and how to choose correctly.
February 19, 20264 min read
Date Partitioning Strategies for High-Performance ClickHouse® Queries
ClickHouse® date partitioning strategies to improve query performance, enable partition pruning, and efficiently manage large time-based data.
February 11, 20267 min read
Optimizing ClickHouse® Queries: From Data Skipping Indexes to Projections
Learn how to optimize ClickHouse® queries by understanding granule storage, data skipping indexes, and projections with real Query logs.
February 11, 20266 min read
ClickHouse® 26.1 Release Notes: A Practical Overview
A technical overview of ClickHouse® 26.1 covering breaking changes, new features, scheduling updates, and upgrade considerations for production deployments.
January 31, 20265 min read
ClickHouse® Schema Design: Using LowCardinality for High-Speed Queries
ClickHouse® LowCardinality explained: Learn how to design schemas for faster queries, lower memory usage, and high-performance analytics.
January 13, 20266 min read
From Billions to Milliseconds: The Architectural Secrets Behind ClickHouse®’s Speed
ClickHouse® delivers fast analytics using columnar storage, vectorized execution, and data skipping to process massive datasets efficiently.
December 18, 20255 min read
ClickHouse® Merge Process: What Happens Behind the Scenes
Learn how the ClickHouse® merge process works behind the scenes, how data parts are merged, why merges matter, and how to optimize MergeTree.
December 6, 20255 min read
Real-Time Pipelines in 2025: How ClickPipes Transforms Data Ingestion
ClickPipes delivers fully managed, reliable data ingestion via streaming, batch, and CDC. Powering real-time analytics in ClickHouse® Cloud.
December 3, 20254 min read
Why Modern Companies Need OLAP Systems Like ClickHouse®
Discover why today’s companies rely on OLAP systems like ClickHouse® for real-time analytics, faster queries, and scalable data processing.
December 3, 20255 min read
ClickHouse® 25.11: A Deep Dive Into New Features, Performance Improvements, and Behavioral Changes
Explore ClickHouse® 25.11 in depth - including new SQL capabilities, object storage improvements, performance optimizations, and important behavioral changes.
November 26, 20255 min read
ClickHouse® 25.10: High-Performance JOINs, QBit Vectors & Smarter SQL
ClickHouse® 25.10 brings faster JOINs, the new QBit vector type, smarter SQL features, and improved Arrow Flight for better analytics.
November 22, 20255 min read
TOON, TOKEN ORIENTED OBJECT NOTATION
Discover TOON Token Oriented Object Notation, the efficient data format revolutionizing how humans and AI communicate.
November 15, 20256 min read
Using UUID as a Primary Key in ClickHouse®: Benefits, Trade-offs, and Real Benchmarks
Discover how UUID performs as a primary key in ClickHouse®. Learn its advantages, trade-offs, and see real benchmark results comparing.
October 16, 20254 min read
ClickHouse® 25.8 LTS: Smarter SQL, PromQL & Iceberg Enhancements
ClickHouse® 25.8 adds PromQL, ArrowFlight RPC, AI-powered SQL, improved Iceberg/Delta Lake, and major performance boosts.
August 28, 20254 min read
ClickHouse® Memory Leak Mystery in 25.3 LTS
Discover how a critical ClickHouse® memory leak was found in 25.3 LTS and fixed, why it caused crashes, and how to prevent it.
August 9, 20252 min read
ClickHouse® 25.7: Practical Features and Smart Optimizations
Discover the new features in ClickHouse® 25.7, from faster UPDATEs to Iceberg table support and improved performance for modern analytics.
August 5, 20253 min read
ClickHouse® 25.6: Time-Series Enhancements, Smarter Merges, and Performance Gains
Explore ClickHouse® 25.6 with time-series enhancements, smarter merges, and performance gains for faster, more efficient analytics
July 31, 20252 min read
ClickHouse® 25.5: Small Changes, Big Impact for Developers & Analysts
ClickHouse® 25.5 release focuses on developer productivity and geospatial accuracy with updates to the geoToH3 function, a new native macOS installer, and.
July 29, 20254 min read
ClickHouse® 25.4: A Smarter and Faster Analytical Database
Discover ClickHouse® 25.4’s new features and performance boosts, making it a smarter, faster choice for analytical workloads
July 25, 20255 min read
JSON Datatype in ClickHouse®, Part 1
Discover how the JSON data type in ClickHouse® 25.3 simplifies and accelerates working with semi-structured data.
April 3, 20255 min read
ClickHouse®, Dynamic Data Type
Discover how Dynamic data type simplifies mixed-type data handling and enhances flexible data modeling in ClickHouse®.
March 23, 20252 min read
BigQuery vs. ClickHouse®: The Cost Trap You Didn’t See Coming
Discover how BigQuery’s pricing model can lead to unexpected costs and why ClickHouse® is a cost-effective, open-source alternative.
March 22, 20253 min read
ClickHouse® as Vector Database
Discover how ClickHouse® can be used as a vector database for AI and ML applications with ANN search and vector indexing.
March 18, 20254 min read
ClickHouse® Memory Management
Learn how to optimize ClickHouse® memory settings, prevent OOM killer interventions, and improve query efficiency for stable performance.
March 8, 20253 min read
ClickHouse® Projections : Turbocharge your queries
Discover the basics of ClickHouse® Projections and Learn how they improve efficiency, enable faster analytics with large-scale workloads.
March 5, 20255 min read