Re: [PATCH] Fix leaky VIEWs for RLS

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> On 04/06/10 17:33, Tom Lane wrote:
>> Maybe the entire idea is unworkable.  I certainly don't find any comfort
>> in your proposal in the above-referenced message to trust index
>> operators; where is it written that those don't throw errors?

> Let's consider b-tree operators for an index on the secure table, for 
> starters. Surely a b-tree index comparison operator can't throw an error 
> on any value that's in the table already, you would've gotten an error 
> trying to insert that.

Man, are *you* trusting.

A counterexample: suppose we had a form of type "text" that carried a
collation specifier internally, and the comparison routine threw an
error if asked to compare values with incompatible specifiers.  An index
built on a column of all the same collation would work fine.  A query
that tried to compare against a constant of a different collation would
throw an error.

> I'm not sure. But indexable 
> operations are what we care about the most; the order of executing those 
> determines if you can use an index scan or not.

Personally, I care just as much about hash and merge join operators...
        regards, tom lane