DROP

Basic Syntax

DROP [TEMPORARY] TABLE [IF EXISTS] [database_name.]name [ON CLUSTER cluster] [SYNC]

Examples:

• Delete the t1 table.

  drop table t1 SYNC;

  

  • When you delete a replication table, create a path on ZooKeeper to store related data. The default library engine of ClickHouse is the atomic database engine. After a table in the atomic database is deleted, it is not deleted immediately but deleted 24 hours later. To resolve this issue, when deleting a table, add the SYNC field to the deletion command, for example, drop table t1 SYNC;
  • This issue does not occur when a local or distributed table is deleted. The SYNC field is not required in your deletion command, for example, drop table t1;
  • If the table creation statement contains ON CLUSTER ClickHouse cluster name, run the following command to delete the table:

    drop table Table name ON CLUSTER default_cluster;

  • If the table creation statement does not contain ON CLUSTER ClickHouse cluster name, run the following command to delete the table:

    drop table Table name;

  • Before deleting a data table, check whether the data table is in use to avoid unnecessary troubles. After a data table is deleted, it can be restored within 24 hours. The restoration command is as follows:

    set allow_experimental_undrop_table_query = 1;

    UNDROP TABLE Data table name;