Re: Jailing a schema from PUBLIC

Rich. Rjamya

>> wild idea,
>>
>> since public access is visible through ALL_* views, you can create local
>> ALL_* views in schema B. These would be essentially same as regular views
>> but you'd filter out owner A.

The dictionary views are just that: views for your convenience. You can tell they aren't used by the SQL engine to do name and privilege resolution - just look at the recursive SQL in a trace file which always refers directly to the underlying dictionary tables (eg OBJ$, TAB$, SEG$, PRV$ etc etc). You can't spoof it into giving you more (or fewer) privileges. So if you've granted S/I/U/D to public on your first database, the only ways to close the door are

1. You can use your two remote schemas - ie use a database that isn't 'infected' by the public grants

Remote schema RA owns the views
Remote schema RB is Vendor B's schema to use

• Create a db link owned by remote user RA create database link LINKA connect to A identified by X using 'servicename';
• And of course, *don't* create a public link, else RB can use it directly and get full SIUD access.
• Create remote views in RA on your original vendor A schema; they will use the DB link create view X as select * from X_at_LINKA;
• Grant required (**limited**) select. insert, update privileges to schema RB grant select, update on X to RB;
• Create synonyms for the views
• Either create public synonyms in the remote database create PUBLIC synonym X for RA.X;
• or create private synonyms as RB

   create synonym X for RA.X;

Now you have full control over what RB can see, and what DML (if any) he can do. (This doesn't include any PL/SQL API access... yet)

2) Or (as you already indicated)

• revoke all public grants of User A objects
• replace them with appropriate private grants to all legitimate Application A users
• Now add user B, and do the right thing

Writing a script for (2) is a fairly trivial exercise; weeding out users who don't need App A (eg SYS, SYSTEM etc) is tedious (but not strictly necessary). You don't need to destroy the public synonyms; they'll be no use to B without the grants.

Option 2 is likely to be easier to set up and maintain...

HTH Regards Nigel

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