# SLEEP

The SLEEP statement is used to introduce a delay or pause in the execution of a query or a batch of queries for a specific amount of time.

The `SLEEP` statement is used to introduce a delay or pause in the execution of a query or a batch of queries for a specific amount of time.

### Statement syntax

**SurrealQL Syntax**

```syntax title="SurrealQL Syntax"
SLEEP @duration;
```

## Example usage

The following query shows example usage of this statement.

```surql
-- Sleep one second
SLEEP 1s;
-- Sleep 100 milliseconds
SLEEP 100ms;
```

For more dynamic usage of sleep, see SurrealDB's [sleep](/docs/reference/query-language/functions/database-functions/sleep.md) function.

## SLEEP during parallel operations

A `SLEEP` statement does not interfere with operations that are underway in the background, such as a [`DEFINE INDEX`](/docs/reference/query-language/statements/define/indexes.md) statement using the `CONCURRENTLY` clause.

```surql
CREATE |user:50000| SET name = id.id() RETURN NONE;
DEFINE INDEX unique_name ON TABLE user FIELDS name UNIQUE CONCURRENTLY;
INFO FOR INDEX unique_name ON TABLE user;
SLEEP 50ms;
INFO FOR INDEX unique_name ON TABLE user;
SLEEP 50ms;
INFO FOR INDEX unique_name ON TABLE user;
SLEEP 50ms;
INFO FOR INDEX unique_name ON TABLE user;
```

```surql title="Possible output"
-------- Query 1 --------
{
	building: {
		count: 0,
		status: 'initial'
	}
}

-------- Query 2 --------
{
	building: {
		count: 17250,
		status: 'initial'
	}
}

-------- Query 3 --------
{
	building: {
		count: 33542,
		status: 'initial'
	}
}

-------- Query 4 --------
{
	building: {
		status: 'built'
	}
}
```

## Use cases

`SLEEP` can be useful in a small number of situations, such as:

* Testing and debugging: can be used to understand how concurrent transactions interact, test how systems handle timeouts and delays, simulate behaviour in more distant regions with longer latency
* Throttling: can be used to throttle the execution of operations to prevent the database from being overwhelmed by too many requests at once
* Security measures: can be used to slow down the response rate of login attempts to mitigate the risk of brute force attacks