Tree-DM has many advantages such as:(1)it only scans transaction database one time; (2)it can find transaction set which includes frequent items set; (3)it has reasonable complexity of time;

• 它利用项目树记录扫描信息,通过项目树的交操作生成事务树,进而利用事务树的交操作逐步产生频繁事务树,该算法的显著特点是能在发现频繁项目集的同时发现这些频繁项目集出现在哪些事务中,并就Tree-DM的性能进行了分析。