v.20.8Improvement

Update: ALTER Query for Version Column in VersionedCollapsingMergeTree

Official CH changelog text
Now it's possible to change the type of version column for VersionedCollapsingMergeTree with ALTER query. #15442 (alesapin).
Enable changing the type of the version column in VersionedCollapsingMergeTree tables using ALTER queries.

Why it matters

This feature allows users to modify the data type of the version column in VersionedCollapsingMergeTree tables without recreating the table. It solves the problem of inflexibility in schema evolution related to version columns, improving manageability and reducing downtime.

How to use it

Use the ALTER TABLE query to change the type of the version column in a VersionedCollapsingMergeTree table. Example syntax:

ALTER TABLE table_name MODIFY COLUMN version_column_name NEW_TYPE

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