Sleep function
This function can be used to introduce a delay or pause in the execution of a query or a batch of queries for a specific amount of time.
| Function | Description |
|---|---|
sleep() | Delays or pauses in the execution of a query or a batch of queries. |
sleep
The sleep function delays or pauses the execution of a query or a set of statements.
API DEFINITIONsleep(duration) -> none
The following example shows this function, and its output, when used in a RETURN statement:
RETURN sleep(1s);
RETURN sleep(500ms);
SurrealDB also has a SLEEP statement statement that accepts a datetime; however, the sleep function can be used in more dynamic ways such as the following example that simulates a 100ms delay between each record in a query.
-- Create 3 `person` records
CREATE |person:3|;
LET $now = time::now();
SELECT *,
sleep(100ms) AS _,
time::now() - $now AS elapsed
FROM person;
Response[
{
_: NONE,
elapsed: 101ms457µs,
id: person:fkgvriz1kl2tcgv6yqfq
},
{
_: NONE,
elapsed: 203ms599µs,
id: person:lgibwdgtvx4v8ck60guk
},
{
_: NONE,
elapsed: 305ms728µs,
id: person:pr0uby896y1az2p44wtw
}
]
Use cases
Putting a database to 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