September 2026 newsletter

ClickHouse released version 26.8, adding custom HTTP handlers, a new `|>` pipelined SQL operator, a `system.user_query_log` table, a URL database engine, and Japanese and Chinese tokenizer support for the text index. The release also includes previews of PromQL, On-Demand Compute, AI functions, and sub-second Postgres replication to ClickHouse, while PostHog ClickHouse engineer Rory Shanks contributed replica mutation-fetch, text-index token caching, and JSON subcolumn read improvements to 26.8. The company's Open House Roadshow continues with stops in Bangalore on Sep 22, London on Sep 30, and Munich on Oct 6.

Hello and welcome to another ClickHouse newsletter We’ve got another feature-packed ClickHouse release, with custom HTTP handlers, pipelined SQL, and Japanese/Chinese tokenizers for the text-index. Elsewhere, Mohamed Hussain S dives into the replication queue, Tom Schreiber and Lionel Palacin share the first end-to-end results from CostBench, and Himanshu Pandey walks us through reading ClickHouse query plans. We also have preview releases of PromQL, On-Demand Compute, AI functions, and sub-second Postgres replication to ClickHouse Featured community member: Rory Shanks This month's featured community member is Rory Shanks, ClickHouse Engineer at PostHog. Rory’s background is in site reliability and cloud platform engineering, and he previously worked as a Staff DevOps Engineer at ENWAY and a Senior Site Reliability Engineer at Inkitt and powercloud. Rory contributed several improvements to ClickHouse 26.8, released at the end of August. First, he added an option for replicas to fetch already mutated data parts https://github.com/ClickHouse/ClickHouse/pull/113020 from another replica, avoiding the need to repeat mutation work locally. Additionally, he added caching for tokens absent from the text index https://github.com/ClickHouse/ClickHouse/pull/112742 and improved JSON subcolumn reads https://github.com/ClickHouse/ClickHouse/pull/113008 by reusing column metadata during conversions. ➡️ Connect with Rory on LinkedIn https://www.linkedin.com/in/rorylshanks/ Open House Roadshow We’re halfway through the Open House Roadshow https://clickhouse.com/company/events?category=Open+House&utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , but there are still visits to come in Bangalore https://clickhouse.com/company/events/202609-APJ-India-Bangalore-Open-House-Roadshow?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter Sep 22 , London https://clickhouse.com/openhouse/london-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter Sep 30 , and Munich https://clickhouse.com/company/events/202610-munich-open-house?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter Oct 6 , so don’t forget to sign up ➡️ See all Open House locations https://clickhouse.com/company/events?category=Open+House&utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter 26.8 release After last month’s mega 26.7 release blog post, we’ve decided to try something different this month: multiple smaller posts The 26.8 release includes a series of features, such as custom HTTP handlers and dynamic query filtering, that enable you to use ClickHouse as a streaming HTTP API https://clickhouse.com/blog/clickhouse-streaming-http-api?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . This release also adds a new | operator that lets us write queries as a sequence of transformations https://clickhouse.com/blog/pipelined-sql-26.8?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . The release also adds a system.user query log table that shows only the current user’s queries, a URL database engine, and Japanese and Chinese tokenizer support for the text index. Understanding the replication queue in ClickHouse Mohamed Hussain S explores ClickHouse’s replication queue by stopping a replica and investigating the backlog. He shows how to use the system.replicas and system.replication queue system tables to diagnose issues, and explains why a non-empty queue doesn’t necessarily mean something is wrong. Measuring real-time performance per dollar under continuous load: CostBench’s first end-to-end results Tom Schreiber and Lionel Palacin share the first end-to-end results from CostBench https://clickhouse.com/blog/costbench-data-warehouse-cost-performance?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , an open benchmark for cloud data warehouse cost-performance: performance-per-dollar, rather than just speed. They test ClickHouse Cloud, Snowflake, BigQuery, and Redshift Serverless under continuous ingestion, measuring the cost of keeping fresh data ready for queries alongside query performance. In a follow-up post, they take a closer look at the ClickHouse Cloud and Snowflake results https://clickhouse.com/blog/clickhouse-vs-snowflake-real-time-performance-per-dollar?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , explaining how their architectures and billing models contribute to the performance-per-dollar gap. Announcing On-Demand Compute: Instant compute for your most intensive workloads This is one of the biggest features we have been working on: On-Demand Compute is now in private preview https://clickhouse.com/cloud/on-demand-compute-waitlist?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . You are now a step away from offloading intensive workloads to dedicated ClickHouse workers. And it doesn’t land alone It comes with two friends: • A new cost-based optimizer CBO • A new distributed query execution framework The dream for anybody wanting to offload ad-hoc or data lake queries to dedicated workers Curious to learn more? Melvyn Peignon will present a live webinar on September 24th https://clickhouse.com/company/events/202609-AMER-Webinar-On-Demand-Compute?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , where he’ll explain how it works, give a live demo, and talk through the six-month roadmap. ClickHouse 26.8 LTS: 57 Breaking Changes Since 26.3 Mohamed Hussain S has written an alternative blog post for the 26.8 release, exploring changes since the previous LTS release, 26.3. He highlights breaking changes and new defaults across all five releases, with a checklist of what to audit before upgrading and monitor afterward. Postgres Round-up We’ve been publishing more and more Postgres content https://clickhouse.com/blog?search=postgres&utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter as the weeks go by, so I thought it deserved its own section in the newsletter. - Sai Srirampur announced WalShadow https://clickhouse.com/blog/introducing-walshadow?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , an open-source engine that replicates Postgres data to ClickHouse directly from the physical WAL. It’s available as an open-source project or in private preview on ClickHouse Managed Postgres https://clickhouse.com/cloud/postgres/walshadow?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . - Kunal Gupta announced the availability of ClickHouse Managed Postgres on Google Cloud https://clickhouse.com/blog/postgres-managed-by-clickhouse-gcp-private-preview?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , also in private preview https://clickhouse.com/cloud/postgres?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter gcp-waitlist for the time being. - David Wheeler announced the open-source chdb Postgres extension https://clickhouse.com/blog/introducing-chdb-postgres?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , which expands Postgres import and export features via the chDB https://clickhouse.com/docs/chdb?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter library. - Gülçin Yıldırım Jelínek has started writing a series of blog posts on Postgres 19. So far, she’s covered monitoring https://clickhouse.com/blog/postgres-19-monitoring-whats-new?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , new system views https://clickhouse.com/blog/postgres-19-new-system-views?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , and read-your-writes https://clickhouse.com/blog/postgresql-19-wait-for-read-your-writes?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . - Kaushik Iska explains how ClickHouse Managed Postgres protects Postgres from resource-hungry supporting processes https://clickhouse.com/blog/protect-postgres-from-supporting-processes?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . - Sai Srirampur explores how storage choices affect Postgres performance https://clickhouse.com/blog/posette-talk-recap-postgres-isnt-slow-your-storage-is?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . - Cristina Albu and Yashpreet Bathla walk through a new onboarding flow for ClickHouse Managed Postgres https://clickhouse.com/blog/clickhouse-managed-postgres-onboarding?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . Introducing ClickHouse's new TimeSeries Engine: Your drop-In Prometheus replacement James Cunningham introduces PromQL and the TimeSeries table engine in ClickHouse Cloud, now in private preview https://clickhouse.com/cloud/promql-support-waitlist?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter . You can send metrics to ClickHouse through Prometheus remote write and query them with PromQL in Grafana, ClickHouse, or ClickStack, all while keeping your existing collection setup. Quick reads - Saarth Soni compares streaming and batch counts of Wikipedia edits https://medium.com/@saarthsoni/wikipulse-what-streaming-and-batch-actually-disagree-about-afbd88e1c267 using Quix Streams and ClickHouse, exploring why the same data can yield different results. - Oleksandr Andrushchenko compares ClickHouse and PostgreSQL for SMS analytics https://medium.com/@oleksandr.andrushchenko1988/clickhouse-vs-postgresql-what-happens-at-billion-row-scale-8506a11f2836 , reporting that ClickHouse processes 10 times more rows and exploring how query shape affects performance. - Himanshu Pandey explains how to read ClickHouse query plans https://medium.com/@hp12/reading-a-clickhouse-explain-plan-ffb4e8353098 to understand query execution and investigate performance. - Andriy Yakovlev and George Larionov introduce AI Functions in ClickHouse https://clickhouse.com/blog/ai-functions-in-clickhouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , bringing AI models into SQL for tasks such as text generation, classification, and embeddings. - Pete Hampton shows how to build semantic search with Google’s MCP Toolbox and ClickHouse https://clickhouse.com/blog/mcp-toolbox-clickhouse-vectors?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , automatically turning text into embeddings for storage and search. - Lareb Zafar introduces ClickGap https://clickhouse.com/blog/clickgap-autonomous-qa-for-clickhouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter , an autonomous QA agent that tests merged ClickHouse changes and traces regressions to the commits that introduced them. Upcoming events Global virtual events - Webinar: What if your most intensive queries could run on more compute? Introducing On-Demand Compute https://clickhouse.com/company/events/202609-AMER-Webinar-On-Demand-Compute?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 24, 2026 AMER - Webinar: What if your most intensive queries could run on more compute? Introducing On-Demand Compute https://clickhouse.com/company/events/202610-EMEA-Webinar-On-Demand-Compute?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 7, 2026 EMEA Virtual training - Query Optimization with ClickHouse Workshop https://clickhouse.com/company/events/202609-APJ-query-optimization-workshop?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 29, 2026 - PostgreSQL and ClickHouse, Better Together https://clickhouse.com/company/events/202609-AMER-PostgreSQL-ClickHouse-Better-Together?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - - Oct 8, 2026 - Real-time Analytics with ClickHouse: Level 1 https://clickhouse.com/company/events/202610-APJ-Real-time-Analytics-ClickHouse-Level1?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 20, 2026 - Real-time Analytics with ClickHouse: Level 2 https://clickhouse.com/company/events/202610-APJ-Real-time-Analytics-ClickHouse-Level2?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 21, 2026 - Real-time Analytics with ClickHouse: Level 3 https://clickhouse.com/company/events/202610-APJ-Real-time-Analytics-ClickHouse-Level3?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 22, 2026 Events in AMER - Rows and Columns summit San Francisco https://luma.com/clickh-wavw - Sep 22nd - Google Cloud Summit Brasil https://cloudonair.withgoogle.com/events/google-cloud-summit-brasil-2026-1 - Sep 23-24, 2026 - Runway by RunReveal https://runway.runreveal.com/ - San Francisco - Sep 29, 2026 - CoreWeave Fully Connected https://coreweave.com/fully-connected-2026 - San Francisco - Sep 29 - Oct 2, 2026 - Sao Paulo In-person training https://clickhouse.com/company/events/202610-LATAM-SaoPaulo-Observability-with-ClickStack/?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Observabilidade com ClickStack - Sao Paulo - Oct 8, 2026 - Sao Paulo Meetup - Observabilidade de Agentes em Escala: o Case do iFood com Langfuse - Sao Paulo - Oct 8, 2026 Events in EMEA - AI Engineer Paris Langfuse - Sept 22-24, 2026 https://ai.engineer/paris/2026 - Stockholm In-Person Training: Real-time Analytics with ClickHouse https://clickhouse.com/company/events/202609-EMEA-Stockholm-Real-time-Analytics-w-ClickHouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 23, 2026 - AI Builders and Databases Barcelona https://luma.com/p7td11mb - Sep 23, 2026 - BigDataLondon - Sept 23-24, 2026 https://www.bigdataldn.com/ - Copenhagen In-person training - Sept 24, 2026 https://clickhouse.com/company/events/202609-EMEA-Copenhagen-Real-time-Analytics-w-ClickHouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - FabCON - Sept 28 - Oct 1 https://espc.tech/conference/fabcon-europe-2026/ - FabCon Lunch and Learn - Sept 30, 2026 https://go2.striim.com/2026-fabcon-ai-roundtable?tracker=clickhouse - AI Builders and Databases Paris https://clickhouse.com/company/events/ai-builders-and-databases-sep-paris-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 29, 2026 - Agentic AI Forum Dubai https://www.agenticaiforum.net/ - Sept 30, 2026 - London In-person training - From 0 to Production: Observing and Improving AI Agents with Langfuse https://clickhouse.com/company/events/202609-EMEA-London-AI-Agents-w-Langfuse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 30, 2026 - London In-person training - One Database, Every Workload: A ClickHouse Workshop https://clickhouse.com/company/events/202609-EMEA-London-One-Database-Every-Workload?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 30, 2026 - Open House Roadshow London https://clickhouse.com/openhouse/london-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 30, 2026 - Munich In-person training - From 0 to Production: Observing and Improving AI Agents with Langfuse https://clickhouse.com/company/events/202610-EMEA-Munich-AI-Agents-w-Langfuse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 6, 2026 - Munich In-person training - One Database, Every Workload: A ClickHouse Workshop https://clickhouse.com/company/events/202610-EMEA-Munich-One-Database-Every-Workload?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 6, 2026 - Open House Roadshow Munich https://clickhouse.com/company/events/202610-munich-open-house?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 6, 2026 - World Summit AI Amsterdam https://worldsummit.ai/ - Oct 7-8, 2026 - AI Builders and Databases Stockholm https://clickhouse.com/company/events/ai-builders-and-databases-oct-stockholm-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 8, 2026 - AI Builders and Databases Tel Aviv https://clickhouse.com/company/events/ai-builders-and-databases-oct-tel-aviv-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 12, 2026 - SRECon Dublin Happy Hour by the Quay https://luma.com/clickh-6n6u - Oct 13, 2026 - SRECon Dublin https://www.usenix.org/conference/srecon25emea - Oct 13-15, 2026 - Data Innovation Summit Dubai https://datainnovationsummit.com/region/mea/ Oct 14-15 - Oslo In-Person Training: Real-time Analytics with ClickHouse https://clickhouse.com/company/events/202610-EMEA-Oslo-Real-time-Analytics-w-ClickHouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 14, 2026 - PostgreSQL Conference Europe - Oct 20-23, 2026 https://www.postgresql.org/about/event/pgconfeu-2026-2587/ - AWS Cloud Days Riyadh https://aws.amazon.com/events/cloud-days/riyadh/ - Oct 21, 2026 - London In-Person Training: Real-time Analytics with ClickHouse https://clickhouse.com/company/events/202610-EMEA-London-Real-time-Analytics-w-ClickHouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 21, 2026 - AI Builders and Analytics London https://clickhouse.com/company/events/ai-builders-and-analytics-oct-london-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 21, 2026 - AI Builders and Databases Dubai https://luma.com/clickh-vtzf - Oct 22, 2026 - Battle of the Quants London - Oct 22, 2026 https://battleofthequants.com/london-2026/ - Dublin In-Person Training: Real-time Analytics with ClickHouse https://clickhouse.com/company/events/202610-EMEA-Dublin-Real-time-Analytics-w-ClickHouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 23, 2026 - AI Builders and Databases Madrid https://luma.com/clickh-1qqg - Nov 3, 2026 - AI Builders and Databases Cyprus https://clickhouse.com/company/events/ai-builders-and-databases-nov-cyprus-2026?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Limassol - Nov 26, 2026 Events in APAC - Open House Roadshow Bangalore https://clickhouse.com/company/events/202609-APJ-India-Bangalore-Open-House-Roadshow?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 22, 2026 - Singapore - From 0 to Production: Observing and Improving AI Agents with Langfuse https://clickhouse.com/company/events/202609-APJ-Singapore-AI-Agents-w-Langfuse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 24, 2026 - Singapore: One Database, Every Workload: A ClickHouse Workshop https://clickhouse.com/company/events/202609-APJ-Singapore-One-Database-Every-Workload?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 24, 2026 - Singapore: Build Better LLM Apps https://clickhouse.com/company/events/build-better-llm-apps-with-langfuse-singapore?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Sep 29, 2026 - Auckland: One Database, Every Workload: A ClickHouse Workshop https://clickhouse.com/company/events/one-database-every-workload-new-zealand?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 6, 2026 - Auckland: Build a unified data stack with Postgres and ClickHouse https://clickhouse.com/company/events/nz-unified-data-stack-postgres-clickhouse?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 6, 2026 - Singapore: Confluent Financial Services Leaders Summit https://events.confluent.io/confluent-fsi-singapore-2026 - Oct 9, 2026 - Sydney: Build a unified data stack for real-time AI with Postgres and ClickHouse https://clickhouse-workshop-syd.innovatusmediaevents.com/ - Oct 13, 2026 - Melbourne: Build Better LLM Apps https://clickhouse.com/company/events/build-better-llm-apps-with-langfuse-melbourne?utm source=clickhouse&utm medium=email&utm campaign=202609-newsletter&ref=newsletter - Oct 15, 2026