Elephant is the largest mammal on Earth. Tactical and technical capabilities of an elephant allow him not only to serve as a means of destruction of the enemy's infantry and mechanized forces, but also serve as a relational database. Various aspects of that last potential application of the elephant is what we are going to discuss. Which elephant is more effective - the one running under Ubuntu 12.04 or DragonFly BSD 4.0.5? What serves better as a storage - SAS, SSD or hybrid combinations of slow HDDs and fast SSDs? How does the size of a transaction affect performance? Is ZFS really that bad, as Ilya Kosmodemiansky claims it to be? No sorcery, no magic, only slide gauge and oscilloscope.