Hi All, Has anyone tried Z-ORDER ing based on concatenated cols of a delta table. Example : if you have a table with the following columns: Order_id Order_dt Order_total And you want to Z-order the table by Order_id and Order_dt using the following syntax: ZORDER BY Order_id + Order_dt. what will be the performance implications ?

You know you can z-order multiple columns, right?

yes I do know, but wanted to know how will be the performance with more than cols. have not tried.

There is a decreasing return with the number of column included. 3 columns is a reasonable limit. You want them to be high cardinality columns, so including a date column for example is not the best usually, but if you can run a few experiments on your data and query patterns that is the best thing to do.

I got it. the combination ZORDER BY Order_id + Order_dt has high cardinality. will his be an option to try out. Pls let me know your thoughts

The syntax is

OPTIMIZE table_name ZORDER BY (Order_id, Order_dt)

That does the order over both columns. It is not a hierarchical sort, so it is essentially clustering by both column values across the curve--values of both columns are parameters to the continuous function.

Thanks @Dominique Brezinski