This package's purpose is to trade safety for execution speed in operations of dpkg (and any program it may execute) by using eatmydata to disable disk synchronization calls. This is useful in situations where data loss in case of a power outage is not a concert, e.g. in setting up ephemeral chroot environments for building Debian packages.
Do not use in production environments where you might care about data integrity!
On installation, /usr/bin/dpkg is moved aside and replaced with a
wrapper script using dpkg-divert(1), this process is of course
reversed when removing this package.