Hyperstage supports common ALTER TABLE commands to add columns to existing tables and modify table structures, the same as you would with a PostgreSQL table. For detailed syntax information, see the PostgreSQL 9.2 Documentation.
psql> ALTER TABLE table_name ADD [COLUMN] col_name col_definition;
psql> ALTER TABLE table_name ADD [COLUMN] col1_name col1_definition, ADD [COLUMN] col2_name col2_definition;
psql> ALTER TABLE table_name DROP [COLUMN] col_name;
Note: Hyperstage only supports DROP of the last added column for the purposes of undo capability. Any column DROP will be supported in a future release.
psql> ALTER TABLE tbl_name RENAME [TO] new_tbl_name;