Alignment specification for PostgreSQL user-defined base types.

Specifies the storage alignment requirement for values of the data type. The allowed values equate to alignment on 1, 2, 4, or 8 byte boundaries. Note that variable-length types must have an alignment of at least 4, since they necessarily contain an int4 as their first component.

§PostgreSQL Documentation

See: https://www.postgresql.org/docs/current/sql-createtype.html

§Examples

CREATE TYPE mytype (
    INPUT = in_func,
    OUTPUT = out_func,
    ALIGNMENT = int4  -- 4-byte alignment
);