After completing my doctorate in computer science, I have started working as a software developer in a middle-sized (several 100 people) company in Germany about 2 years ago. After repeatedly commenting on how excellent my work is during that time, my superior has told me several times already during the past few weeks that he cannot give me more money unless I come and ask for it, and that I should really request a performance review appointment for that purpose.
Now, I absolutely abhor any kind of negotiations, especially when it's about getting benefits for myself. It's one of the primary reasons why I chose to stay in academia instead of entering the industry some 7 years ago when I started my doctorate (getting a fixed salary at the university based on a pre-defined matrix), and it's also the reason why, during my employment at this company of two years, I have somewhat procrastinated the (in theory annual) performance review so far1.
I have no idea how I can approach the topic of getting "more money" during such a performance review appointment. I do not know whether my superior was referring to a raise of my agreed upon salary, or to a bonus of some sort (e.g. as a higher (> 100%?) percentage of the variable portion of my salary). I also have no clue what I should answer if they want to know a concrete number. Or could my superior's words have just been a polite way of him expressing he appreciates my work (he would give me more money, even though it's not possible from the side of the company)?
How can I find out what is appropriate to ask and where I am overstepping some line or seem undeservedly greedy by asking for something that was never in consideration for me?
While I am on good terms with everyone in my team, I do not have a close enough contact to anyone that I could possibly dare to ask them about their salary (even if this weren't a breach of contract for them, anyway).
Please note that "Don't set up a performance review and stick with your current salary." is not a useful answer here. I am fully aware that this is one of my options; I am trying to find out about the specifics of the option to request the performance review.
1: While the reasons of my colleagues may differ, skipping or delaying that annual review seems to be a very common thing done in this company. Hence, I don't think I am sticking out with my behavior.