Advisory on Arch: it's necessary to update regularly, if not weekly preferably, due to cutting edge package versions and changing dependency/package versions. This will save unnecessary issues or time concerning maintenance tasks and keep your install working smooth-as-butter. Arch is a rolling distribution, offering the best and latest in software with a small but worthwhile price of simple, regular maintenance updates being mandatory --- the design of this distribution and its package management.
pacman -Qe - List explictly-installed packages
pacman -Ql >pkg< - List files belonging to package
pacman -Qii >pkg< - List info on package
pacman -Qo >file< - List owner of file
pacman -Qs >query< - Search installed packages for keywords
pacman -Syup - Synch pkg db, only print to screen updates