v.18.14Improvement

New Feature: 'partition_key' Alias in clickhouse-copier WHERE Expressions

In a user-defined WHERE expression in clickhouse-copier, you can now use a partition_key alias (for additional filtering by source table partition). This is useful if the partitioning scheme changes during copying, but only changes slightly. #3166
Added support for using a partition_key alias in user-defined WHERE expressions within clickhouse-copier to enable filtering by source table partition.

Why it matters

This feature addresses scenarios where the partitioning scheme of a table changes slightly during data copying. It allows users to apply additional fine-grained filtering based on the source table's partitions, improving control and efficiency in data migration tasks.

How to use it

When defining a custom WHERE clause in clickhouse-copier, include the partition_key alias to filter source partitions as needed. This provides an easy way to selectively copy data based on partition values.