Very often, if I call 'Find Usages' on a method, IDEA is searching for several minutes (ca. 5 minutes), even though there might be one usage only which is even in the same class.
For example, searching for usages of MyClass.getForm() (which is not overriden nor part of an interface or something like that) in 'Project Files' scope:
'Search for form...' shows up in the progress bar and moves from 1% to 2% to 3%. in baby steps.
Maybe an important detail:
The progress bar shows up twice in a row: the first one shows up and progresses very quickly and then the second progress bar shows up that starts from zero again and progresses very slowly. Maybe it searches in all text files as well...
Doing the same search several times in a row, the search time remains the same.