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