SLEEP
Waits a specified number of seconds before executing another statement or command.
	Waits a specified number of seconds before executing another statement or command.
This is a meta-function. You must call meta-functions in a top-level SELECT statement.
Behavior type
VolatileSyntax
SLEEP( seconds )
Parameters
seconds- The wait time, specified in one or more seconds (0 or higher) expressed as a positive integer. Single quotes are optional; for example, 
SLEEP(3)is the same asSLEEP('3'). 
Notes
- 
This function returns value 0 when successful; otherwise it returns an error message due to syntax errors.
 - 
You cannot cancel a sleep operation.
 - 
Be cautious when using SLEEP() in an environment with shared resources, such as in combination with transactions that take exclusive locks.
 
Examples
The following command suspends execution for 100 seconds:
=> SELECT SLEEP(100);
 sleep
-------
     0
(1 row)