os x terminal command.
sudo mdutil -a -i off
sudo mdutil -a -i on
Usage: mdutil -pEsa -i (on|off) -d volume ...
Utility to manage Spotlight indexes.
-p Publish metadata.
-i (on|off) Turn indexing on or off.
-d Disable Spotlight activity for volume (re-enable using -i on).
-E Erase and rebuild index.
-s Print indexing status.
-a Apply command to all volumes.
-V vol Apply command to all stores on the specified volume.
-v Display verbose information.
NOTE: Run as owner for network homes, otherwise run as root.
“sudo mdutil -a -i off” which turns off indexing only.
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist
source: How to Disable (or Enable) Spotlight in Mac OS X Mavericks & Mountain Lion
これをオフにしたままだとApp StoreでXcodeとかのアップデートができないので、「他のアカウントでお試しください」みたいなアラートが出た時は一回オンにしましょう。