Transition from partitioned table to Liquid clustered table

[mjedy78]

Hi all,
I have a table called classes, which is already partitioned on three different columns. I want to create a Liquid Clustered Table, but as far as I understand from the documentation—and from Dany Lee and his team—it was not possible as of 2024 YouTube Video.

I believe there is still no smooth transition. So, I want to recreate the table, but is the only way to do this by creating a new table, deleting the old one, and moving everything from new_table to the old table’s location?

%sql
-- Step1
CREATE TABLE IF NOT EXISTS class_clustered
CLUSTER BY (id, family, result_date)
LOCATION 'my_new_table_location'
AS
SELECT *
FROM class(the main partitioned table);

-- Step2
DROP class

-- Step3
Remove location in dbfs

-- Step4
Move everything from location my_new_table_location --> old location(for class partitioned)

Can I overwrite it or do something similar without too much effort? 😃 There are more than 20 tables that need to be converted to Liquid Clustered Tables, so I’m looking for the best approach.

[MariuszK]

You can enable liquid clustering on an existing table:

ALTER TABLE <table_name>
CLUSTER BY (<clustering_columns>)

You need to run OPTIMIZE FULL to force reclustering.

[mjedy78]

@MariuszK It is for normal tables and will not work with the partitioned ones 

[MariuszK]

I'm sorry, I missed that your tables are partitioned, in this case easiest  way will be to recreate it.

[biancaorita]

Is there a plan to implement a way to migrate to liquid clustering for an existing table that has traditional partitioning and that is quite large (over 4 TB)? Re-creating such tables from scratch is not always ideal.

[jeffrey-gong]

You're in luck! The feature to easily convert a partitioned table to Liquid Clustering is in Private Preview - please reach out to your account team to try it. User Guide