Syntax
------

DROP INDEX [IF EXISTS] index_name ON tbl_name 
  [WAIT n |NOWAIT]

Description
-----------

DROP INDEX drops the index named index_name from the table tbl_name. This
statement is mapped to an ALTER TABLE statement to drop the index.

If another connection is using the table, a metadata lock is active, and this
statement will wait until the lock is released. This is also true for
non-transactional tables.

See ALTER TABLE.

Another shortcut, CREATE INDEX, allows the creation of an index.

To remove the primary key, `PRIMARY` must be specified as index_name. Note
that the quotes are necessary, because PRIMARY is a keyword.

Privileges
----------

Executing the DROP INDEX statement requires the INDEX privilege for the table
or the database.

Online DDL
----------

Online DDL is used by default with InnoDB, when the drop index operation
supports it.

See InnoDB Online DDL Overview for more information on online DDL with InnoDB.

DROP INDEX IF EXISTS ...
------------------------

If the IF EXISTS clause is used, then MariaDB will return a warning instead of
an error if the index does not exist.

WAIT/NOWAIT
-----------

Sets the lock wait timeout. See WAIT and NOWAIT.

Progress Reporting
------------------

MariaDB provides progress reporting for DROP INDEX statement for clients that
support the new progress reporting protocol. For example, if you were using
the mariadb client, then the progress report might look like this::

URL: https://mariadb.com/kb/en/drop-index/