Confused about rights

Greetings,

I am just starting to use postgresql (7.0.2, on Debian), and I am rather
confused about how to use its access rights (grant/revoke). Two questions
in particular:

(1) I created a database and table as a super-user, then started to GRANT
away. The first thing I noticed is that UPDATE and DELETE rights are
actually the same in postgresql - did I get that right? So I can't actually
give the right to change anything in a table without also giving the right
to completely erase all rows from it?

(2) The COPY command documentation says that COPY ... FROM STDIN requires
"insert OR update" rights to the table. I tried to set up a non-privileged
user with just INSERT rights on a table, but COPY rejects an attempt to
COPY unless I (also, or just) grant UPDATE rights to that user. I can use
INSERT commands just fine with just INSERT rights, but not COPY. Is that a
feature or a bug? (It is definitely annoying - I wanted to set up a "least
privileged" account for a web server to just dump data into the table, so
it can't possibly change or delete anything once it's stored there.)

I tried to browse/search the mailing list archives and "interactive
documentation", but I guess I don't know the magic keywords to look for...

Thanks
  -- perry
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Perry The Cynic                                             perry@cynic.org
To a blind optimist, an optimistic realist must seem like an Accursed Cynic.
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