SELECT COLUMN_NAME,
       DATA_TYPE,
       CHARACTER_MAXIMUM_LENGTH,
       NUMERIC_PRECISION,
       NUMERIC_SCALE,
       IS_NULLABLE,
       SUBSTR(COALESCE(COLUMN_DEFAULT, '' ), 1, 8 ) = 'nextval(' AS IS_AUTOINCREMENT,
       COLUMN_DEFAULT
FROM   INFORMATION_SCHEMA.COLUMNS
WHERE  TABLE_NAME = 'xxxxxxxx'
ORDER BY ORDINAL_POSITION

(publié à l'origine sur http://www.bigbold.com/snippets/posts/show/816)