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The ALTER TABLE statement applies a schema change to a table.
Note:
To understand how CockroachDB changes schema elements without requiring table locking or other user-visible downtime, see Online Schema Changes in CockroachDB.Subcommands
For information on using ALTER TABLE, see the documents for its relevant subcommands.
| Subcommand | Description |
|---|---|
ADD COLUMN |
Add columns to tables. |
ADD CONSTRAINT |
Add constraints to columns. |
ALTER COLUMN |
Change or drop a column's Default constraint or drop the Not Null constraint. |
DROP COLUMN |
Remove columns from tables. |
DROP CONSTRAINT |
Remove constraints from columns. |
EXPERIMENTAL_AUDIT |
Enable per-table audit logs. |
PARTITION BY |
New in v2.0: Repartition or unpartition a table with partitions (Enterprise-only). |
RENAME COLUMN |
Change the names of columns. |
RENAME TABLE |
Change the names of tables. |
SPLIT AT |
Force a key-value layer range split at the specified row in the table. |
VALIDATE CONSTRAINT |
Check whether values in a column match a constraint on the column. |
Viewing Schema Changes
Whenever you initiate a schema change, CockroachDB registers it as a job, which you can view with SHOW JOBS.
