Most mining tools need to have data in a flat file format in order to start sorting through it,so the data is extracted and put in a flat text file.Then the mining process can begin.

• 多数挖掘工具需要采用平面文件格式的数据，以便开始筛选数据，所以数据被提取出来并放进平面文本文件中，然后挖掘过程才能开始。