A system and method of identifying relational patterns across a plurality of databases using a data structure and the data structure itself. The data structure including one or more data node branches, each of the one or more data node branches including one or more data nodes, each of the one or more data nodes representing a data item of interest and corresponding data item support values for the data item across the plurality of databases in relation to other data items represented in the data node branch. The data structure can be used to mine one or more relational patterns considering pattern support data across the plurality of databases at the same time.