detached_parts
Contains information about detached parts of MergeTree tables. The reason
column specifies why the part was detached.
For user-detached parts, the reason is empty. Such parts can be attached with ALTER TABLE ATTACH PARTITION|PART command.
For the description of other columns, see system.parts.
If part name is invalid, values of some columns may be NULL
. Such parts can be deleted with ALTER TABLE DROP DETACHED PART.