A system includes determination of a match between a first table column of a plurality of table columns of database tables and a second table column of the plurality of table columns, determination, based on stored metadata, of a first data dictionary associated with the first table column and a second data dictionary associated with the second table column, merging of the first data dictionary and the second data dictionary to generate a merged data dictionary, and modification of the stored metadata to associate the first data dictionary with the merged data dictionary and to associate the second data dictionary with the merged data dictionary.