A method, system and computer program product for identifying reference data tables in an Extract-Transform-Load (ETL) process, by identifying, by operation of one or more computer processors, at least a first reference data operator in the process, wherein the first reference data operator references one or more tables and evaluating at least a first table referenced by the reference data operator to determine whether the first table is a reference data table by assigning a score to the first table, wherein the score is indicative of the likelihood that the first table is a reference data table and wherein a reference data table contains a set of values that describes other data.