Why after moving exist table to tablespace, memory table data still there? (no replies)

Hi, there.

How can I delete the table in Memory after using ALTER TABLE and move the table to disk data?
It seems after I use ALTER TABLE to move the exist table in DataMemory to disk, using cmd:
ALTER TABLE tb01 TABLESPACE ts01 STORAGE DISK NDB;

The DamaMemory increased, but no space is used in the tablespace.
And from the information_schema.partision, we can see the table exists in the tablespace.

Why is like this?

So if we want to move a table from Memory to Disk, do we need to DROP the table first and use "CREATE TABLE ...TABLESPACE ts01 STORAGE DISK NDB" to store it on the disk?

Thanks very much