having to do with machinery: a mechanical failure. 2. being a machine; operated by machinery: a mechanical toy. 3. caused by or derived from machinery: mechanical propulsion.
ERROR: cannot alter type of a column used by a view or rule DETAIL: rule _RETURN on view v_change_me depends on column too_short. Though PostgreSQL tells us which view and column prompted this error, thatâs the last favor it provides.
However, if the computed column value is defined by a deterministic expression and the data type of the result is allowed in index columns, a computed column can be used as a key column in an index or as part of any PRIMARY KEY or UNIQUE constraint.