For most companies, raises are most often tied to a yearly planning cycle and most often that is tied to the company's fiscal year. The exception being if you actually change jobs (you get promoted and take on additional responsibility OR you accept a transfer into another role), more often than not a raise is offered in either case.
If you've been promoted or transferred in your first eight months and didn't get a raise, I would say that is not normal. If your job has stayed the same, again I would say it is normal, but would start asking questions at around 12 months. It's perfectly normal in any job you've been in for a year, in any situation, to inquire about a raise. Per my comment above about the yearly planning cycle, timing is sometimes for you, sometimes against. Ex. If company raises/merit increases went into effect on April 1 and you started on February 15th, there's a good chance you would have to wait until April 1 of the following year to get a raise, 13 plus months.
Hope this helps! Bottom-line, likely perfectly normal, but don't hesitate to speak with your manager as you come up on a full year in role.