Sleep function in ORACLE

I need execute an SQL query in ORACLE it takes a certain amount of time. So I wrote this function:

CREATE OR REPLACE FUNCTION MYSCHEMA.TEST_SLEEP
(
TIME_  IN  NUMBER
)
RETURN INTEGER IS
 BEGIN
   DBMS_LOCK.sleep(seconds => TIME_);
RETURN 1;
 EXCEPTION
   WHEN OTHERS THEN
   RAISE;
   RETURN 1;
END TEST_SLEEP;

and I call in this way

SELECT TEST_SLEEP(10.5) FROM DUAL

but to work I need set grant of DBMS_LOCK to the owner of the procedure.

How I can rewrite this function without using the DBMS_LOCK.sleep function?

Short of granting access to DBMS_LOCK.sleep, this will work but it's a horrible hack:

IN_TIME INT; --num seconds
v_now DATE;

-- 1) Get the date & time 
SELECT SYSDATE 
  INTO v_now
  FROM DUAL;

-- 2) Loop until the original timestamp plus the amount of seconds <= current date
LOOP
  EXIT WHEN v_now + (IN_TIME * (1/86400)) <= SYSDATE;
END LOOP;

Create a procedure which just does your lock and install it into a different user, who is "trusted" with dbms_lock ( USERA ), grant USERA access to dbms_lock.

Then just grant USERB access to this function. They then wont need to be able to access DBMS_LOCK

( make sure you don't have usera and userb in your system before running this )

Connect as a user with grant privs for dbms_lock, and can create users

drop user usera cascade;
drop user userb cascade;
create user usera default tablespace users identified by abc123;
grant create session to usera;
grant resource to usera;
grant execute on dbms_lock to usera;

create user userb default tablespace users identified by abc123;
grant create session to userb;
grant resource to useb

connect usera/abc123;

create or replace function usera.f_sleep( in_time number ) return number is
begin
 dbms_lock.sleep(in_time);
 return 1;
end;
/

grant execute on usera.f_sleep to userb;

connect userb/abc123;

/* About to sleep as userb */
select usera.f_sleep(5) from dual;
/* Finished sleeping as userb */

/* Attempt to access dbms_lock as userb.. Should fail */

begin
  dbms_lock.sleep(5);
end;
/

/* Finished */

From Oracle 18c you could use DBMS_SESSION.SLEEP procedure:

This procedure suspends the session for a specified period of time.

DBMS_SESSION.SLEEP (seconds  IN NUMBER)

DBMS_SESSION.sleep is available to all sessions with no additional grants needed. Please note that DBMS_LOCK.sleep is deprecated.

If you need simple query sleep you could use WITH FUNCTION:

WITH FUNCTION my_sleep(i NUMBER)
RETURN NUMBER
BEGIN
    DBMS_SESSION.sleep(i);
    RETURN i;
END;
SELECT my_sleep(3) FROM dual;

There is a good article on this topic: PL/SQL: Sleep without using DBMS_LOCK that helped me out. I used Option 2 wrapped in a custom package. Proposed solutions are:

Option 1: APEX_UTIL.sleep

If APEX is installed you can use the procedure “PAUSE” from the publicly available package APEX_UTIL.

Example – “Wait 5 seconds”:

SET SERVEROUTPUT ON ;
BEGIN
    DBMS_OUTPUT.PUT_LINE('Start ' || to_char(SYSDATE, 'YYYY-MM-DD HH24:MI:SS'));
    APEX_UTIL.PAUSE(5);
    DBMS_OUTPUT.PUT_LINE('End   ' || to_char(SYSDATE, 'YYYY-MM-DD HH24:MI:SS'));
END;
/

Option 2: java.lang.Thread.sleep

An other option is the use of the method “sleep” from the Java class “Thread”, which you can easily use through providing a simple PL/SQL wrapper procedure:

Note: Please remember, that “Thread.sleep” uses milliseconds!

--- create ---
CREATE OR REPLACE PROCEDURE SLEEP (P_MILLI_SECONDS IN NUMBER) 
AS LANGUAGE JAVA NAME 'java.lang.Thread.sleep(long)';

--- use ---
SET SERVEROUTPUT ON ;
BEGIN
    DBMS_OUTPUT.PUT_LINE('Start ' || to_char(SYSDATE, 'YYYY-MM-DD HH24:MI:SS'));
    SLEEP(5 * 1000);
    DBMS_OUTPUT.PUT_LINE('End   ' || to_char(SYSDATE, 'YYYY-MM-DD HH24:MI:SS'));
END;
/

If executed within "sqlplus", you can execute a host operating system command "sleep" :

!sleep 1

or

host sleep 1