Hola rrufino.
Para los obtener nombres, tipos y valores de dominios podrías hacer:
Código SQL
[-]
SELECT T1.RDB$FIELD_NAME AS F_NAME,
CASE T1.RDB$FIELD_TYPE
WHEN 7 THEN 'SMALLINT'
WHEN 8 THEN 'INTEGER'
WHEN 9 THEN 'QUAD'
WHEN 10 THEN 'FLOAT'
WHEN 11 THEN 'D_FLOAT'
WHEN 12 THEN 'DATE'
WHEN 13 THEN 'TIME'
WHEN 14 THEN 'CHAR'
WHEN 16 THEN 'INT64'
WHEN 27 THEN 'DOUBLE'
WHEN 35 THEN 'TIMESTAMP'
WHEN 37 THEN 'VARCHAR'
WHEN 40 THEN 'CSTRING'
WHEN 261 THEN 'BLOB'
ELSE 'UNKNOWN TYPE'
END AS F_TYPE,
T1.RDB$FIELD_LENGTH AS F_LENGTH,
T1.RDB$FIELD_PRECISION AS F_PRECISION,
T1.RDB$FIELD_SCALE AS F_SCALE
FROM RDB$FIELDS T1
WHERE NOT (RDB$FIELD_NAME LIKE 'RDB$%')
En cuanto a modificarlos, revisa este enlace: [
Alter domain ]
Saludos.