We have fairly complex build process where each build produces 400 jacoco exec files which are total of 80MB, in addition of exec files jacoco is also keeping snapshot of source code and class files which is drastically increasing the cost for keeping historical build which we all want to keep.

Jacoco plugin should make it configurable to persist old Java/Class files or not, as generating trend chart shouldn't require keeping the entire data set but trend chart can be generated incrementally, as most people wouldn't need to go and analyze older code coverage reports.