That's the theory. In practice, it is near-impossible to get any enterprise vendor to actually fix something. Either you're lucky and another customer had the problem. Then, after annoying them for about a week, you'll get a patch.

If however you've found something new like a feature that's so buggy it is actually completely defect, you're in for an ordeal of a few months. Simply getting a dev to look at your bug takes a month. In that month, you'll answer every day questions like what OS you're on ('As I told your past 10 colleagues, We see it under red hat linux version X1 X2 X3, and under windows Y1 and Y2, and under HPUX Z. Yes, this is a pristine OS install with a pristine JVM. Yes, our support contract covers this. There is a test case in the bug report, run it on your computer and see yourself'). They'll call you in the middle of the night. Then call you again 12 hours later because you're not allowed to respond to their questions outside business hours so please tell us again and next time read your contract.

If you survive this, and you provide a perfect example source code fragment of 100 lines, and you decompile their own code, point at the bug, and suggest a less insane way to write that code, you'll get a fix. This fix seems to work for up to a day, when you notice your performance is less than a sixt from what it was. Then you notice how they ignored your suggestion, did something even less sane than the original code, and managed to break something else you hadn't even noticed before.

Call again, insist they do not start a new ticket unless you want to redo that original month. A few minutes later they call back and try to sell you six times the hardware you have as a workaround, and promise a 10% price reduction for the first year. Do not swear at any point, this will immediately end the phone call and you'll have to navigate their insane phone menu again and get a new lesson in Indian English from a guy who swears he is speaking your language perfectly right now (which is neither English or anything spoken in India, afaik).

After a few rounds of this, they produce a working patch. You confirm it works and are promptly forbidden to use it ever again. They will provide you 'soon' with an official version of the patch, which has been vetted against their secure development lifecycle, legal team, and god knows what else. Actually applying the current patch so your users stop screaming will end your support contract.

It takes in total a bit more than 3 months before the final patch is delivered. At that point:

1) management congratulates themselves for having bought support.

2) Your colleagues however are in awe about you've got actually managed to get an enterprise vendor th actually fix a bug. Turns out they have tons and tons of bugs and spend their days inventing horrible workarounds as they gave up getting them fixed long ago.

3) Contractors from the enterprise vendor, working on another project in your company will turn the feature off, as they know for sure it can't work. If you claim to have a patch and it is already running on their servers, they refuse to use it and turn the feature off once more. Not using the feature costs a small fortune in network overhead, BTW. If you enable it, the next coontractor entering the building will disable it instantly, even if your config file has this story documented.

Anyway, thats my experience. YMMV.