@Andreas,

hast Du das ausprobiert oder vermutest Du das nur?
(Ich kann es erst heute Abend ausprobieren, da ich aktuell kein Zugriff auf eine 6.1 Maschine habe)
... die Dokumentation lässt zumindest auf etwas anderes schließen:


ALL:
Selects all rows of the final result table and does not eliminate duplicates. This is the default.

DISTINCT:
Eliminates all but one of each set of duplicate rows of the final result table. Two rows are duplicates of one another only if each value in the first row is equal to the corresponding value in the second row. (For determining duplicate rows, two null values are considered equal.) The collating sequence is also used for determining distinct values. DISTINCT is not allowed if the select-list contains a DATALINK column.

Select list notation *:
Represents a list of columns of table R in the order the columns are produced by the FROM clause. Any columns defined with the hidden attribute will not be included. The list of names is established when the statement containing the SELECT clause is prepared. Therefore, * does not identify any columns that have been added to a table after the statement has been prepared.
Birgitta