FIND-20260409-003 · 2026-04-09 · Innovation Veille
ClickHouse 26.3.4.11-stable released — async insert default, full-text search GA, vector index scaling
release
HIGH
ClickHouse 26.2 (Winter Release, Feb 2026) and the subsequent 26.3 stable (Apr 8 2026) bring the most extensive performance changes in the project's history. Key changes: async insert now ON by default for all inserts; deduplication enabled by default; bucketed Map serialization gives 2-49x speedup for single-key lookups; full-text search with tokenizers is now GA; vector indexes can exceed single-VM memory. Observability via embedded ClickStack, native TOTP auth, and Google BigLake integration.
Source
https://github.com/ClickHouse/ClickHouse/releases/tag/v26.2.8.15-stable
ODS Impact
ODS Data Platform uses ClickHouse as the OLAP store for Zero-ETL pipeline (Redpanda -> Debezium -> ClickHouse). The async insert default change is a breaking behavior change — existing insert code may behave differently. The deduplication default and async batching will affect Redpanda Kafka engine tables used for CDC ingestion. ClickHouse administrators must review settings before upgrading. Full-text search GA is relevant for future DocStore and SecureMail analytics. Recommend testing 26.3 in staging before upgrading production.
Security Review
License: Apache-2.0 | Maintenance: ACTIVE | Risk: LOW | Recommendation: SAFE_TO_USE
Tags
clickhouse
olap
zero-etl
data-platform
release
breaking-change