Altinity Stable Build for ClickHouse® 25.8

Altinity Stable® Build for ClickHouse® 25.8 is now available! As Altinity users are aware, Altinity Stable Builds are based on ClickHouse Long Term Support releases and maintained for three years. We build them for organizations who value stable operation without major upgrades for long periods of time. 

Version 25.8 Release Summary

Development always moves fast in the ClickHouse GitHub project. More than 300 contributors from companies all around the world submitted 3200+ pull requests with new features and improvements. We spent several months testing the new version and tracking fixes merged to the 25.8 LTS branch. We also collected early adopter feedback on upgrades as well as feature changes that affect production use.

One example of that is the high memory usage due to very wide system tables. Another detective story was a broken DDL worker that affected many new Docker and Kubernetes deployments. Now that they are fixed, we are confident in certifying 25.8 as ready for use. 

Detailed release notes for Altinity Stable Build 25.8 are available on the Altinity Documentation Site. There are a lot of new features, but also many behavior changes, so check the release notes carefully before upgrading. 

Differences Between Altinity Stable Builds and Upstream Official Builds

Like upstream builds, Altinity Stable builds for ClickHouse are open source and are based on upstream LTS versions. Altinity Stable Build version 25.8.16.10001 is based on upstream 25.8.16.34-lts, but we have additionally backported several fixes from newer versions:

• ALTER MODIFY COLUMN now requires explicit DEFAULT when converting nullable columns to non-nullable types. Previously such ALTERs could get stuck with cannot convert null to not null errors. Now NULLs are replaced with column’s default expression (ClickHouse#84770 by @vdimir via #1344)
• Added new SQL statement EXECUTE AS to support user impersonation (ClickHouse#70775 by @shiyer7474, ClickHouse#90437 by @alexbakharew via #1340)
• Fix crash in StorageDistributed when parsing malformed shard directory names (ClickHouse#90243 by @AVMusorin via #1343)
• Datalake catalogs will be shown in system introspection tables only if show_data_lake_catalogs_in_system_tables explicitly enabled (ClickHouse#88341 by @alesapin via #1331)
• ClickHouse will show data lake catalog database in SHOW DATABASES query by default (ClickHouse#89914 by @alesapin via #1331)
• Possible crash/undefined behavior in IN function where primary key column types are different from IN function right side column types (ClickHouse#89367 by @ilejn via #1339)
• Fixed move-to-prewhere optimization, which did not work in the presence of row policy (ClickHouse#87303 by @KochetovNicolai via #1345)
• Fixes a bug where certain distributed queries with ORDER BY could return ALIAS columns with swapped values (i.e., column a showing column b’s data and vice versa) (ClickHouse#94644 by @filimonov via #1346)
• Split part ranges by volume characteristics to enable TTL drop merges for cold volumes. After this patch, parts with a max TTL < now will be removed from cold storage. The algorithm will schedule only single part drops. (ClickHouse#90059 by @Michicosun via #1363)
• Check and mark the interserver IP address active in DDL worker (ClickHouse#92339 by @tuanpach via #1403)
• Fix handling of users with a dot in the name when added via config file (ClickHouse#86633 by @mkmkme via #1342)
• S3Queue auxiliary Zookeeper support using keeper_path setting from s3Queue (ClickHouse#95203 by @lesandie via #1357)
• SELECT query with FINAL clause on a ReplacingMergeTree table with the is_deleted column now executes faster because of improved parallelization from 2 existing optimizations (ClickHouse#88090 by @shankar-iyer via #1332)
• Reduce INSERT/merges memory usage with wide parts for very wide tables by enabling adaptive write buffers. Add support of adaptive write buffers for encrypted disks (ClickHouse#92250 by @azat via #1341)

We have also disabled one setting to allow safe downgrade from 25.8 to 25.3:

• Disable write_marks_for_substreams_in_compact_parts by default to preserve downgrade compatibility (#1407 by @zvonand)

Let’s Install!

Altinity Stable build packages for different Linux distributions can be found at https://builds.altinity.cloud. 

Altinity Stable build container images are available as altinity/clickhouse-server:25.8.16.10001.altinitystable on Docker Hub.

Altinity.Cloud users may upgrade to a new build using Cluster Upgrade wizard.

For more information on installing Altinity Builds, see the Altinity Stable® Builds Install Guide. Please contact us at support@altinity.com if you experience any issues with the upgrade.

Project Antalya or Altinity Stable?

Altinity Stable builds are focused on safe upgrades and stability for production operation. If you are interested in the newest features for data lakes, Iceberg, Parquet and other cool stuff, try out Project Antalya builds. Those represent the latest Altinity work on the Project Antalya.

Want More Information About Altinity Stable Builds? 

Check out our blog article on the upgrade philosophy behind Altinity Stable Builds and how it differs from official ClickHouse builds. Altinity supports both builds, so you can choose whichever is best for you!