Re: [v9.2] Fix leaky-view problem, part 2

Yeb Havinga <yebhavinga@gmail.com>

From: Yeb Havinga <yebhavinga@gmail.com>
To: Kohei KaiGai <kaigai@kaigai.gr.jp>
Cc: Robert Haas <robertmhaas@gmail.com>, Noah Misch <noah@2ndquadrant.com>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Kohei Kaigai <Kohei.Kaigai@emea.nec.com>, Stephen Frost <sfrost@snowman.net>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-07-20T07:02:59Z
Lists: pgsql-hackers
On 2011-07-09 09:14, Kohei KaiGai wrote:
> OK, I'll try to modify the patch according to the flag of pg_proc design.
> As long as the default of user-defined function is off, and we provide
> built-in functions
> with appropriate configurations, it seems to me the burden of DBA is
> quite limited.

A different solution to the leaky view problem could be to check access 
to a tuple at or near the heaptuple visibility level, in addition to 
adding tuple access filter conditions to the query. This would have both 
the possible performance benefits of the query rewriting solution, as 
the everything is filtered before further processing at the heaptuple 
visibility level. Fixing leaky views is not needed because they don't 
exist in this case, the code is straightforward, and there's less change 
of future security bugs by either misconfiguration of leakproof 
functions or code that might introduce another leak path.

regards,

-- 
Yeb Havinga
http://www.mgrid.net/
Mastering Medical Data