It is estimated that the world's total data is approximately 2.8 zettabytes (1 zettabyte: 1 trillion gigabytes) by 2012. When this statement is first read, we can imagine that most of the raw data has been retained in tables of the databases. However, this data treasure is not as easy to find as it seems. We may identify this treasure with the mystical treasure to that of El-Dorado.