[kross]

His check-call on the flop probably means he doesn't yet have a pair.

His donk on the turn probably means he either picked up a draw with an 8, or he just made a pair with a 9.

His river donk could either be him betting his 9 again, because he doesn't want you to check behind, or it could be he had a straight draw on the turn, and just now picked up a pair (i.e. J8)

It could be an outright bluff, his turned straight draw not getting there, etc.

It could also be runner runner two pair.

So, it it's a bluff, he most likely won't call your raise. If it's a one-pair hand, he will probably call. If it's two pair, you're most likely toast.

So I think a call is better than a raise.