Re: Re: [SQL] Foreign keys breaks tables permissions

Hannu Krosing wrote:
> 
> Hiroshi Inoue wrote:
> >
> > Tom Lane wrote:
> >
> > > "Stephan Szabo" <sszabo@kick.com> writes:
> > > > I believe the reason that the trigger does a select for update was
> > > > because otherwise there could exist a case that we select and see it
> > > > and then have the row go away afterwards because nothing stops the
> > > > delete.
> > >
> > > Probably the denial-of-service argument is the weakest of the three
> > > points.  Is anyone in favor of reducing SELECT FOR UPDATE to only
> > > requiring "SELECT" rights, and living with the possible lock-that-
> > > you-shouldn't-really-have-been-able-to-get issue?
> > >
> >
> > But what about DELETE CASCADE cases for exmaple ?
> > Maybe RI_trigger should be able to update/insert/delete
> > the referenced table.
> > However another kind of permission for foreign key
> > seems to be needed. i.e only granted users could
> > define foreign key of the referenced table in CREATE
> > (ALTER) TABLE command.
> 
> IIRC this is even in the SQL standard as a separate right (maybe REFERENCES ?)

Here's from SQL92 draft:
We should at least consider it when designing our GRANT system

.........

         4.26  Privileges

         A privilege authorizes a given category of <action> to be per-
         formed on a specified base table, view, column, domain,
character
         set, collation, or translation by a specified <authorization
iden-
         tifier>. The mapping of <authorization identifier>s to
operating
         system users is implementation-dependent. The <action>s that
can be
         specified are:

         -  INSERT

         -  INSERT (<column name list>)

         -  UPDATE

         -  UPDATE (<column name list>)

         -  DELETE

         -  SELECT

         -  REFERENCES

         -  REFERENCES (<column name list>)

         -  USAGE

 .......


         A privilege descriptor with an action of INSERT, UPDATE,
DELETE,
         SELECT, or REFERENCES is called a table privilege descriptor
and
         identifies the existence of a privilege on the table identified
by
         the privilege descriptor.

         A privilege descriptor with an action of SELECT (<column name
         list>), INSERT (<column name list>), UPDATE (<column name
list>),
         or REFERENCES (<column name list>) is called a column privilege
de-
         scriptor and identifies the existence of a privilege on the
column
         in the table identified by the privilege descriptor.

         Note: In this International Standard, a SELECT column privilege
         cannot be explicitly granted or revoked. However, for the sake
         of compatibility with planned future language extensions,
SELECT
         column privilege descriptors will appear in the Information
Schema.

         A table privilege descriptor specifies that the privilege iden-
         tified by the action (unless the action is DELETE) is to be au-
         tomatically granted by the grantor to the grantee on all
columns
         subsequently added to the table.

         A privilege descriptor with an action of USAGE is called a
usage
         privilege descriptor and identifies the existence of a
privilege on
         the domain, character set, collation, or translation identified
by
         the privilege descriptor.

         A grantable privilege is a privilege associated with a schema
that
         may be granted by a <grant statement>.

         The phrase applicable privileges refers to the privileges
defined
         by the privilege descriptors that define privileges granted to
the
         current <authorization identifier>.

         The set of applicable privileges for the current <authorization
         identifier> consists of the privileges defined by the privilege
         descriptors associated with that <authorization identifier> and
         the privileges defined by the privilege descriptors associated
with
         PUBLIC.

         Privilege descriptors that represent privileges for the owner
of
         an object have a special grantor value, "_SYSTEM". This value
is
         reflected in the Information Schema for all privileges that
apply
         to the owner of the object.


........

         11.36  <grant statement>

         Function

         Define privileges.

         Format

         <grant statement> ::=
              GRANT <privileges> ON <object name>  
                TO <grantee> [ { <comma> <grantee> }... ]
                  [ WITH GRANT OPTION ]

         <object name> ::=
                [ TABLE ] <table name>
              | DOMAIN <domain name>
              | COLLATION <collation name>
              | CHARACTER SET <character set name>
              | TRANSLATION <translation name>


-----------
Hannu