2.2 KiB
| toc_priority | toc_title |
|---|---|
| 43 | DETACH |
DETACH Statement
Deletes information about the table or view from the server. The server stops knowing about their existence.
Syntax:
DETACH TABLE|VIEW [IF EXISTS] [db.]name [PERMANENTLY] [ON CLUSTER cluster]
Detaching does not delete the data or metadata for the table or view. If the table or view was not detached PERMANENTLY, on the next server launch the server will read the metadata and recall the table/view again. If the table or view was detached PERMANENTLY, there will be no automatic recall.
Whether the table was detached permanently or not, in both cases you can reattach it using the ATTACH query (with the exception of system tables, which do not have metadata stored for them).
ATTACH MATERIALIZED VIEW doesn't work with short syntax (without SELECT), but you can attach it using the ATTACH TABLE query.
Note that you can not detach permanently the table which is already detached (temporary). But you can attach it back and then detach permanently again.
Also you can not DROP the detached table, or CREATE TABLE with the same name as detached permanently, or replace it with the other table with RENAME TABLE query.
Similarly, a “detached” table can be re-attached using the ATTACH query (with the exception of system tables, which do not have metadata stored for them).
DETACH PERMANENTLY
Deletes information about name table or view from the server. Permanently detached tables won't automatically reappear after the server restart.
Syntax:
DETACH TABLE/VIEW [IF EXISTS] [db.]name PERMAMENTLY [ON CLUSTER cluster]
This statement does not delete the table’s data or metadata.
Permanently detached table or view can be reattached with ATTACH query and can be shown with SHOW CREATE TABLE query.