Multiple roles assigned to an user

Question

Hi folks,
My question sounds to be something weird, but wanted to be cautious. I see a lot of users in my environment with multiple roles assigned to them. When i checked the roles of an user who has three roles assigned to him, i noticed that all the roles have some tables in common with the same grants in all the three roles, and all these three roles are assigned to the same user. Will there be any problem?
An example to explain my senerio...
User scott has three roles A,B and C assigned to him. All the three roles have execute on xy.abc procedure and select,insert,update,delete on xy.xyz table. Will there be any problem to the user who is assigned all these three roles. Will there be any confusion from oracle to chooose from which role?
Thanks

Answer 1

This sounds to be something new. So When a oracle
tries to hold all the privileges does it do a
distinct on the table grants, so that i will have
just one entry of the privilege of an object, though
it exists in all the roles assigned to that user.No, the table objauth$ looks like this,
  1* select * from objauth$ where rownum < 100
SYS@etest> /
      OBJ#   GRANTOR#   GRANTEE# PRIVILEGE#  SEQUENCE# PARENT                OPTION$       COL#
       133          0          5          0          1
       133          0          5          3          2
       133          0          5          5          3
       133          0          5          6          4
       133          0          5          9          5
       133          0          5         10          6
       133          0          5         11          7
       135          0          5          0          8
       135          0          5          3          9
       135          0          5          5         10
       135          0          5          6         11
      OBJ#    GRANTOR#  GRANTEE# PRIVILEGE#  SEQUENCE# PARENT                OPTION$       COL#
---------- ---------- ---------- ---------- ---------- ------------------ ---------- ----------where
OBJ# is object ID, could be any object not only table,
GRANTOR# is user# , ROLE is also considered a special USER internally in Oracle.
SYS@etest> select user#, name from user$
  2  /
     USER# NAME
         0 SYS
         1 PUBLIC
         2 CONNECT
         3 RESOURCE
         4 DBA
         5 SYSTEM
         6 SELECT_CATALOG_ROLE
         7 EXECUTE_CATALOG_ROLE
         8 DELETE_CATALOG_ROLE
         9 EXP_FULL_DATABASE
        10 IMP_FULL_DATABASE
..............So different roles will have different records in objauth$. Even it's same privilege of same object granted to same user.
a GRANTEE# can have same privilege to the same object from different GRANTOR#