Re: missing data in information_schema grant_* tables?

Hello pgdevs,

I'm trying to use the information_schema, and I'm looking at the grant
tables. ISTM that some views do not show all expected permissions.

psql> CREATE TABLE foo();
psql> CREATE USER calvin NOLOGIN;
psql> GRANT SELECT ON TABLE foo TO calvin;
psql> GRANT INSERT ON TABLE foo TO PUBLIC; -- not really a good idea

psql> \dp
Access privileges
Schema | Name | Type | Access privileges | Column access privileges
--------+------+-------+-----------------------+--------------------------
public | foo | table | fabien=arwdDxt/fabien |
: calvin=r/fabien
: =a/fabien

INSERT to PUBLIC is shown on the last line of the access privileges
column. However, when looking at the information_schema:

psql> SELECT grantor, grantee, privilege_type
FROM information_schema.role_table_grants
WHERE table_name = 'foo';
grantor | grantee | privilege_type
---------+---------+----------------
fabien | fabien | SELECT
fabien | fabien | INSERT
fabien | fabien | UPDATE
fabien | fabien | DELETE
fabien | fabien | TRUNCATE
fabien | fabien | REFERENCES
fabien | fabien | TRIGGER
fabien | calvin | SELECT
(8 rows)

My point is that the grant to "PUBLIC" does not show in the information
schema. However, it appears in the table_privileges view:

psql> SELECT grantor, grantee, privilege_type FROM
information_schema.table_privileges WHERE table_name='foo';
grantor | grantee | privilege_type
---------+---------+----------------
... same as previous query ...
fabien | PUBLIC | INSERT

(1) Would you agree that it is a "bug"? That is, if the grantee is PUBLIC,
it is an enabled role for the current user, so it should appear in the
role_table_grants view...

(2) If yes is the answer to the previous question, and in order to fix it,
would it be acceptable to drop the view definitions of role_table_grants
based on the pg_catalog and rely on the table_privileges view instead, if
possible (it looks so, but there may be some issues)? Or should the
current view definition be simply reworked?

--
Fabien.

On fre, 2010-01-15 at 12:00 +0100, Fabien COELHO wrote:
> INSERT to PUBLIC is shown on the last line of the access privileges
> column. However, when looking at the information_schema:
>
> psql> SELECT grantor, grantee, privilege_type
> FROM information_schema.role_table_grants
> WHERE table_name = 'foo';
> grantor | grantee | privilege_type
> ---------+---------+----------------
> fabien | fabien | SELECT
> fabien | fabien | INSERT
> fabien | fabien | UPDATE
> fabien | fabien | DELETE
> fabien | fabien | TRUNCATE
> fabien | fabien | REFERENCES
> fabien | fabien | TRIGGER
> fabien | calvin | SELECT
> (8 rows)
>
> My point is that the grant to "PUBLIC" does not show in the
> information
> schema. However, it appears in the table_privileges view:
>
> psql> SELECT grantor, grantee, privilege_type FROM
> information_schema.table_privileges WHERE table_name='foo';
> grantor | grantee | privilege_type
> ---------+---------+----------------
> ... same as previous query ...
> fabien | PUBLIC | INSERT
>
> (1) Would you agree that it is a "bug"? That is, if the grantee is
> PUBLIC,
> it is an enabled role for the current user, so it should appear in
> the
> role_table_grants view...

The whole point of role_table_grants is that it shows everything that
table_privileges shows except privileges granted to public. So the
behavior you observe is correct.

Dear Peter,

>> (1) Would you agree that it is a "bug"? That is, if the grantee is
>> PUBLIC, it is an enabled role for the current user, so it should appear
>> in the role_table_grants view...
>
> The whole point of role_table_grants is that it shows everything that
> table_privileges shows except privileges granted to public. So the
> behavior you observe is correct.

This is not my understanding of ISO/IEC 9075-11:2003(E), page 57 :

"5.39 ROLE_TABLE_GRANTS view

Function

Identifies the privileges on tables defined in this catalog that are
available or granted by the currently applicable roles."

From the definition above, ISTM that a privilege granted to PUBLIC should
also appear, both because it is granted by me and available to me.

Moreover, if I execute the SELECT of the view definition provided in the
standard (a little bit simplified, and executed on the information schema
instead of the "definition schema"), the PUBLIC stuff is displayed :

psql> SELECT grantor, grantee, table_name
FROM information_schema.table_privileges
WHERE grantee IN (SELECT role_name FROM information_schema.enabled_roles)
OR grantor IN (SELECT role_name FROM information_schema.enabled_roles);

...
fabien | calvin | foo
fabien | PUBLIC | foo

I think that the view definition in postgresql could simply reuse the view
defined in the standard.

--
Fabien.

On fre, 2010-01-15 at 15:06 +0100, Fabien COELHO wrote:
> > The whole point of role_table_grants is that it shows everything that
> > table_privileges shows except privileges granted to public. So the
> > behavior you observe is correct.
>
> This is not my understanding of ISO/IEC 9075-11:2003(E), page 57 :

You're right, it's a bug, but it's already fixed in 8.5. :-)

>> This is not my understanding of ISO/IEC 9075-11:2003(E), page 57 :
>
> You're right, it's a bug, but it's already fixed in 8.5. :-)

Great! :-)

Thanks,

--
Fabien.