COMMENT ON [ [ DATABASE | INDEX | RULE | SEQUENCE | TABLE | TYPE | VIEW ] object_name | COLUMN table_name.column_name| AGGREGATE agg_name agg_type| FUNCTION func_name (arg1, arg2, ...)| OPERATOR op (leftoperand_type rightoperand_type) | TRIGGER trigger_name ON table_name ] IS 'text'
COMMENT adds a comment to an object that can be easily retrieved with psql's \dd, \d+, or \l+ commands. To remove a comment, use NULL. Comments are automatically dropped when the object is dropped.
Comment the table mytable:
COMMENT ON mytable IS 'This is my table.';
Some more examples:
COMMENT ON DATABASE my_database IS 'Development Database';
COMMENT ON INDEX my_index IS 'Enforces uniqueness on employee id';
COMMENT ON RULE my_rule IS 'Logs UPDATES of employee records';
COMMENT ON SEQUENCE my_sequence IS 'Used to generate primary keys';
COMMENT ON TABLE my_table IS 'Employee Information';
COMMENT ON TYPE my_type IS 'Complex Number support';
COMMENT ON VIEW my_view IS 'View of departmental costs';
COMMENT ON COLUMN my_table.my_field IS 'Employee ID number';
COMMENT ON AGGREGATE my_aggregate (double precision) IS 'Computes sample variance';
COMMENT ON FUNCTION my_function (timestamp) IS 'Returns Roman Numeral';
COMMENT ON OPERATOR ^ (text, text) IS 'Performs intersection of two text';
COMMENT ON TRIGGER my_trigger ON my_table IS 'Used for R.I.';