DROP INDEX
Syntax
DROP [ONLINE|OFFLINE] INDEX [IF EXISTS] index_name ON tbl_name [algorithm_option | lock_option] algorithm_option: ALGORITHM [=] {DEFAULT|INPLACE|COPY} lock_option: LOCK [=] {DEFAULT|NONE|SHARED|EXCLUSIVE}
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.
IF EXISTS
MariaDB starting with 10.1.4
The IF EXISTS
clause was added in MariaDB 10.1.4
When the IF EXISTS
clause is used, MariaDB will return a warning instead of an error if the index does not exist.
ONLINE/OFFLINE
MariaDB starting with 10.0
The ONLINE
and OFFLINE
clauses have been removed in MariaDB 10.0.
Progress reporting
MariaDB starting with 5.3
Since MariaDB 5.3 this statement supports progress reporting.