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1.9 KiB
1.9 KiB
slug | sidebar_label |
---|---|
/en/sql-reference/statements/undrop | UNDROP |
UNDROP TABLE
Cancels the dropping of the table.
Beginning with ClickHouse version 23.3 it is possible to UNDROP a table in an Atomic database
within database_atomic_delay_before_drop_table_sec
(8 minutes by default) of issuing the DROP TABLE statement. Dropped tables are listed in
a system table called system.dropped_tables
.
If you have a materialized view without a TO
clause associated with the dropped table, then you will also have to UNDROP the inner table of that view.
:::note UNDROP TABLE is experimental. To use it add this setting:
set allow_experimental_undrop_table_query = 1;
:::
:::tip Also see DROP TABLE :::
Syntax:
UNDROP TABLE [db.]name [UUID '<uuid>'] [ON CLUSTER cluster]
Example
set allow_experimental_undrop_table_query = 1;
CREATE TABLE undropMe
(
`id` UInt8
)
ENGINE = MergeTree
ORDER BY id
DROP TABLE undropMe
SELECT *
FROM system.dropped_tables
FORMAT Vertical
Row 1:
──────
index: 0
database: default
table: undropMe
uuid: aa696a1a-1d70-4e60-a841-4c80827706cc
engine: MergeTree
metadata_dropped_path: /var/lib/clickhouse/metadata_dropped/default.undropMe.aa696a1a-1d70-4e60-a841-4c80827706cc.sql
table_dropped_time: 2023-04-05 14:12:12
1 row in set. Elapsed: 0.001 sec.
UNDROP TABLE undropMe
Ok.
SELECT *
FROM system.dropped_tables
FORMAT Vertical
Ok.
0 rows in set. Elapsed: 0.001 sec.
DESCRIBE TABLE undropMe
FORMAT Vertical
Row 1:
──────
name: id
type: UInt8
default_type:
default_expression:
comment:
codec_expression:
ttl_expression: