If the corpus used in the appendix of someone else's paper is exactly the same as yours, the corpus you use may be duplicate with others' appendix. However, just because two people use the same corpus does not mean that their appendices are repetitive, because everyone has different purposes and methods when choosing and using corpus. In addition, in most studies, appendices usually provide supplementary information of data independently of other parts, so the repetition of appendices usually does not affect your research results. However, when quoting other people's research results in the paper, we should pay attention to quoting and indicating the source.