(you don't have to strictly follow this form)

Use case

We use materialized columns extensively in our analytics app to speed up queries on a lot of free-form json data where the structure is not static.

Managing these columns is however a pain because:

• Adding them, the data starts trickling in only forwards
• To populate the data for historic data, you need to OPTIMIZE the whole data or partition. https://clickhouse.tech/docs/en/sql-reference/statements/optimize/

Describe the solution you'd like

Extend optimize statement to allow materializing only one column.

OPTIMIZE TABLE [db.]name [ON CLUSTER cluster] [COLUMN mat_column] [PARTITION partition | PARTITION ID 'partition_id']

Ex: OPTIMIZE TABLE mytable ON CLUSTER cluster COLUMN mycolumn

Describe alternatives you've considered

Optimizing our whole dataset every time we materialize a column. This runs into issues due to heavy I/O

Additional context

Add any other context or screenshots about the feature request here.