A parable about the agility that "Touch It, Take It" adds to data warehousing; and the extra work that a misuse of "You Aren't Going to Need It" creates.
Once, there was a great chief called Yagni. Chief Yagni's village was very prosperous and had grown much during his rule. Eventually, Chief Yagni decided that it was time for the village to have a new gathering space as the old one had been well out grown. So, Chief Yagni recruited 2 strong men, Gwyn and Titi, to bring stones from the quarry to the village center so that a group of builders could stack them into the new gathering space.
Gwyn and Titi both arrived on Monday morning to receive their directions from Chief Yagni. Yagni reviewed the building plans and told Gwyn and Titi that he needed 20 large flat square stones for the base of the building. Gwyn and Titi took their push carts down to the quarry, gathered rocks, and returned to the village center. They emptied their rocks together in piles for Chief Yagni's review. Gwyn's pile had exactly 10 flat square stones. Titi's had 10 flat square stones and 3 smaller angled stones.
"Why are these here?" asked Yagni.
"I had to pick them up off of the flat stones in the quarry," replied Titi, "so I thought I would just bring them along in case there was a use for them."
"Get rid of them!" shouted Yagni angrily. "You've wasted time in gathering those worthless rocks I did not ask you to collect. We need 10 tall narrow stones for the doorway. Go back to the quarry and bring me those. Only those, Titi! When you see the other rocks, tell yourself that You Aren't Going to Need It."
Gwyn smiled at Titi's scolding, feeling proud that he'd followed the chief's directions so precisely. Titi still believed that the angled stones might eventually come in handy, though. Gwyn and Titi began pushing their carts back to the quarry. Gwyn's light and empty. Titi's partly full of unwanted rocks.
Frustrated, not wanting to push the angled rocks all the way back to the quarry, Titi dumped the extra rocks in a small pile just outside of chief Yagni's sight.
Gwyn and Titi gathered the tall narrow stones the chief asked for. Titi, again, had to clear angled rocks from on top of the narrow stones, and added them to his cart. This time, Titi paused and dropped the extra angled stones on his pile just outside of Chief Yagni's sight.
Gwyn and Titi returned to the chief with their carts full of only tall narrow stones and the chief was pleased with them both. This continued for several more trips until the new meeting place was nearly complete. Gwyn following directions exactly and Titi always bring back more than asked, but leaving the extra angled rocks on his pile. By this time, Titi has accumulated a large enough pile of angled stones to fill his entire cart.
On their last delivery to Chief Yagni, the chief looked over the plans again and stroked his chin in thought. "Gwyn, Titi," he said. "I need you to bring some angled stones for the roof. Like those that you brought back on the first trip, Titi. Go back to the quarry and bring me two carts full of those."
Gwyn and Titi hurried back toward the quarry. Gwyn went to the quarry and began collecting his cart full of angled rocks, but Titi had the large pile he had been accumulating during his other trips. He stopped just outside of the chief's sight, collected all of his angled rocks into his cart, and returned to the chief well before Gwyn had even loaded half of his own rocks.
"Titi. How did you gather these rocks so quickly, when Gwyn hasn't returned yet?"
Titi explained to his chief that when he had to pick up a stone anyway, he decided that if he had to Touch It, then he should Take It.
The chief was please with Titi's foresight and promoted him to lead rock collector.