My company is in the process of testing Sybase 15 with one of our homegrown apps. Since I am the new guy on the DBA team this project got dumped on me. This is OK by me since I think it is a great opportunity to learn some new things and I have. Anyway, I went through and found out everything that I needed to know in order to get the DB server installed and get all the disk devices setup and created the DBS for load. Once I did that I loaded the Databases and watched as ASE upgraded the Databases from 12.5 to 15. Everything seemed to go great. The only problem that I really ran into here was that I had to drop all encryption and set that up again. Other then that everything went great. I handed the server over to the developers and said it is all yours start testing. So they did just that. A couple weeks into the testing, with no major issue, I get an email saying that they have a stored proc that runs in a few minutes on 12.5 and never completes in 15.0. I and my team looked into this and the developers did as well. We could not really figure out what was going on. We say that the optimizer was doing things differently in 15 then in 12.5 but were not sure why. We opened a case with Sybase and after a couple weeks of communications and sending them data the level one support person agreed that we had a problem, he could replicate the issue, and was flying this up to engineering. A week later we finally hear back and they say that engineering can not duplicate the issue and that we do not have a issue. Let me assure you that we still had an issue. By this time I had gone to my training class and I had mentioned this to the instructor. He kinda laughed about it but I am sure that he would have helped out more if I asked. Instructor at class was very good and very knowledgeable. Anyway a day or two later I get an email from one of our contract developers saying that he has a solution. WOW this is great news and the solution is actually pretty simple. This should work for anyone having a similar issue. I am not sure that this is always the best solution but all he did was force the 12.5 plan on the 15.0 optimizer. I mentioned this to the instructor and he agreed that in this case this was a good solution. So anyone having a similar issue this should get you running until Sybase can help you find another solution if in fact another solution exists.
Thanks and please let me know if you have any questions.