1. A computer-implemented method comprising: populating a first data record in a first data source and a second data record in a second data source with manually selected, representative sample data, the first and second data sources using respective first and second data storage schemas to store the representative sample data as instance values of instance elements; selecting a first instance value of the first data record; selecting instance elements of the second data record whose associated instance values form a substring of the first instance value; generating one or more succession graphs using the instance elements, wherein each of the one or more succession graphs comprises: nodes representing the associated instance values of the second data record, and one or more lines connecting at least two nodes, each of the one or more lines indicating a succession relationship between the associated instance values represented by the at least two nodes and the first instance value of the first data record; selecting a succession graph from the one or more succession graphs whose combined instance values, when traced from a root node to a leaf node, provide the first instance value; automatically determining parameters for a CONCATENATE function or an EXTRACT function based on the succession graph; storing the CONCATENATE function or the EXTRACT function; and converting non-sample data between the first and second data storage schemas of the respective first and second data sources, by executing the CONCATENATE function or the EXTRACT function, the CONCATENATE function, when executed, combining a plurality of instance values from the first data storage schema to provide an instance value in the second data storage schema, and the EXTRACT function, when executed, parsing an instance value from the first data storage schema to provide a plurality of instance values in the second data storage schema.