# ALTER INDEX

The `ALTER INDEX` statement applies a schema change to an index. For information on using `ALTER INDEX`, see the pages for its relevant subcommands.

Note:

This statement performs a schema change. For more information about how online schema changes work in CockroachDB, see Online Schema Changes.

## Subcommands

Subcommand | Description
--- | ---
`CONFIGURE ZONE` | Configure replication zones for an index.
`PARTITION BY` | Partition, re-partition, or un-partition an index. (Enterprise-only).
`RENAME` | Change the name of an index.
`SPLIT AT` | Force a range split at the specified row in the index.
`UNSPLIT AT` | Remove a range split enforcement at a specified row in the index.

## Viewing schema changes

This schema change statement is registered as a job. You can view long-running jobs with `SHOW JOBS`.