Uninstalling an app will remove entry from `/data/system/packages.xml`, and delete package from:

* `/data/app/` (apk file)  
* `/data/data/` (user data and cache)  
* `/data/dalvik-cache/arm/` (translated java bytecode to executable dalvik bytecode)

Clear cache can performed from the android settings. Custom recovery twrp has option for wipe the dalvik cache.