Tiger barbs and goldfish living in the same tank together will have different outcomes, it will depends on the size of your fish, the aggression, and what species of goldfish is it. I have a 1 inch comment living with 4 half an inch Tiger barbs in a heated tank for almost a year and there has been no conflicts between the fish and zero deaths. If they goldfish don't work then try; Red tail, Rainbow, or Bala sharks.
To all the people who think that goldfish are cold water, goldfish more likely to get bladder disease in cold water. That is why I keep my goldfish in tropical temperatures.
Best of luck,
fish keeper 101