FIND-20260404-019 · 2026-04-04 · Innovation Veille
ClickHouse 26.3 LTS Released — Breaking Changes + Default Async Inserts
release
HIGH
ClickHouse 26.3 LTS (v26.3.3.20, released April 1 2026) is the new long-term support branch. Key changes: async inserts now ON by default (batching), deduplication ON by default for all inserts including materialized views, NOT operator precedence fix (SQL standard alignment — may break existing queries), MySQL data type defaults updated. ODS is on 26.2.6.27-stable — upgrade to 26.3 LTS should be planned with query compatibility testing.
Source
https://quantrail-data.com/clickhouse-26-3-lts-features-performance-guide/
ODS Impact
ClickHouse is ODS analytics backend. All materialized views feeding from Debezium/Redpanda CDC pipeline may behave differently with async inserts and deduplication defaults. Kafka engine tables using INSERT INTO ... SELECT must be tested. The NOT operator precedence change may affect any analytics queries or Metabase reports. Schedule upgrade testing in staging before promoting.
Security Review
License: Apache-2.0 | Maintenance: ACTIVE | Risk: LOW | Recommendation: SAFE_TO_USE
Tags
clickhouse
release
lts
analytics
breaking-change
data-platform