# DROP INDEX

The `DROP INDEX` command drops the specified index on the specified table.

## Syntax

```
DROP INDEX <key_name | index_name> ON <table_name>;

```

## Remarks

* `<key_name | index_name>` is the name of the index you want to drop.
* `<table_name>` is the name of a table in a SingleStore Helios database.
* This command will attempt to run as an online operation, but in certain cases cannot. See [ALTER TABLE](https://docs.singlestore.com/cloud/reference/sql-reference/data-definition-language-ddl/alter-table.md) for more information. Operations that be run offline cannot be run on distributed tables.
* `SORT KEY` indexes and `FULLTEXT` indexes cannot be dropped using `DROP INDEX`. If a table having these indexes is dropped, the indexes are deleted automatically.
  > **📝 Note**: `KEY() USING CLUSTERED COLUMNSTORE` is a legacy syntax that is equivalent to `SORT KEY()`. SingleStore recommends using `SORT KEY()`.
* SingleStore Helios supports online `DROP INDEX`, which means that you can read and write while the index is being dropped on a table. `DROP INDEX` on a sharded table is always executed online. Note that online `DROP INDEX` will not begin dropping the index on the table, but it will wait until all DML queries that were already running on the table finish. This allows any in-progress queries to complete execution before dropping the index on the table, and ensures consistency of results from queries on the table since the time of execution of `DROP INDEX`. As soon as the in-progress reads and writes complete and the `DROP INDEX` command begins dropping the index on the table, new reads and writes will proceed as normal. This blocking period usually lasts approximately for milliseconds.

  If you are running frequent `DROP INDEX` statements on a table and have a lot of long-running queries on that table, then your normal workload may experience some periods of delay since it blocks other queries from starting while it waits for the completion of long-running queries.

  Refer to the [Query Errors](https://docs.singlestore.com/cloud/reference/troubleshooting-reference/query-errors.md) topic for resolving query timeout errors due to long-running queries in a workload.
* Refer to the [Permissions Matrix](https://docs.singlestore.com/cloud/reference/sql-reference/security-management-commands/permissions-matrix.md) for the required permissions.

## Examples

## DROP INDEX for a Named Index

```sql
CREATE TABLE drop_ind_1 (a INT, b INT, c INT, INDEX ind_1 (b));
```

```sql
DROP INDEX ind_1 ON drop_ind_1;

```

## DROP INDEX for an Unnamed Index with a Single Column

```sql
CREATE TABLE drop_ind_2 (a INT, b INT, c INT, INDEX (b));
```

```sql
DROP INDEX b ON drop_ind_2;
```

## DROP INDEX for an Unnamed Index with Multiple Columns

```sql
CREATE TABLE drop_ind_3 (a INT, b INT, c INT, INDEX (a,b));
```

Execute the `SHOW INDEX` command to find the `Key_name`.

```sql
SHOW INDEX FROM drop_ind_3;

```

```output

+------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------------+---------+---------------+---------------+
| Table      | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type       | Comment | Index_comment | Index_options |
+------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------------+---------+---------------+---------------+
| drop_ind_3 |          1 | a        |            1 | a           | NULL      |        NULL |     NULL |   NULL | YES  | COLUMNSTORE HASH |         |               |               |
| drop_ind_3 |          1 | a        |            2 | b           | NULL      |        NULL |     NULL |   NULL | YES  | COLUMNSTORE HASH |         |               |               |
+------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------------+---------+---------------+---------------+
```

The `Key_name` is used in the `DROP INDEX` command to drop the multiple-column index.

```sql
DROP INDEX a ON drop_ind_3;
```

***

Modified at: June 11, 2026

Source: [/cloud/reference/sql-reference/data-definition-language-ddl/drop-index/](https://docs.singlestore.com/cloud/reference/sql-reference/data-definition-language-ddl/drop-index/)

(An index of the documentation is available at /llms.txt)