This CREATE TABLE AS … WITH DATA request creates a new NUSI index on column_2 of target_table. The request also copies the data from the selected columns into target_table.
Because the request specifies a subquery and no explicit table kind is specified, the table kind of target_table defaults to the session mode default, not to the table kind of subquery_table.
CREATE TABLE target_table ( column_1, column_2) AS (SELECT * FROM subquery_table ) WITH DATA INDEX (column_2);