Desktop Indexing is a service in KDE desktop which is useful but most of the time it hogs the system memory and processing power. For a home user, it good to disable it for saving some valuable system process.
Earlier it was Nepomuk, now its Baloo, is the program behind this. Here is a simple tip to disable it and save up
You can make your file manager display hidden files, after which go to
$HOME/.kde/share/config/baloofilerc. It is enough to edit it and change the option
to (or add if there is not such option)
to disable baloo.