(2010/07/08 22:08), Robert Haas wrote: > I think we pretty much have conceptual agreement on the shape of the > solution to this problem: when a view is created with CREATE SECURITY > VIEW, restrict functions and operators that might disclose tuple data > from being pushed down into view (unless, perhaps, the user invoking > the view has sufficient privileges to execute the underlying query > anyhow, e.g. superuser or view owner). What we have not resolved is > exactly how we're going to decide which functions and operators might > do such a dastardly thing. I think the viable options are as follows: > > 1. Adopt Heikki's proposal of treating indexable operators as non-leaky. > > http://archives.postgresql.org/pgsql-hackers/2010-06/msg00291.php > > Or, perhaps, and even more restrictively, treat only > hashable/mergeable operators as non-leaky. > > 2. Add an explicit flag to pg_proc, which can only be set by > superusers (and which is cleared if a non-superuser modifies it in any > way), allowing a function to be tagged as non-leaky. I believe that > it would be reasonable to set this flag for all of our built-in > indexable operators (though I'd read the code before doing it), but it > would remove the need for the assumption that third-party operators > are equally sane. > > CREATE OR REPLACE FUNCTION doesnt_leak() RETURNS integer AS $$SELECT > 42$$ IMMUTABLE SEAWORTHY; -- doesn't leak > > This problem is not going away, so we should try to decide on something. > I'd like to vote the second option, because this approach will be also applied on another aspect of leaky views.
When leaky and non-leaky functions are chained within a WHERE clause, it will be ordered by the cost of functions. So, we have possibility that leaky functions are executed earlier than non-leaky functions. It will not be an easy work to mark built-in functions as either leaky or non-leaky, but it seems to me the most straight forward solution. Thanks, -- KaiGai Kohei <kai...@ak.jp.nec.com> -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
