Automatic append includes: identifying, based at least in part on contents of a first data set comprising a first plurality of columns and contents of a second data set comprising a second plurality of columns, a plurality of matching columns and a plurality of non-matching columns. The matching columns comprise one or more columns among the first plurality of columns; and corresponding one or more matching columns among the second plurality of columns. The non-matching columns comprise: one or more columns among the first plurality of columns that do not match with any columns among the second plurality of columns; and one or more columns among the second plurality of columns that do not match with any columns among the first plurality of columns. Automatic append further includes obtaining a user specification of a first one or more non-matching columns to be appended to a second one or more non-matching columns, the first one or more non-matching columns and the second one or more non-matching columns being selected among the plurality of non-matching columns; and appending the first data set and the second data set according to at least the identified plurality of matching columns and the user specification.