Volkan,
> CREATE SEQUENCE document_docorder_seq START 1;
>
> UPDATE document
> SET docorder = T.docorder
> FROM (SELECT nextval('document_docorder_seq') AS docorder, docdate
> FROM document
> ORDER BY docdate) AS T
> WHERE document.docdate = T.docdate;
>
> DROP SEQUENCE document_docorder_seq;
thank you. Excellent.
Andrus.