After database security is hardened, the oracle user cannot be used to connect to the Oracle database or receive alarm and performance data in the I2000, why?

Possible Causes
After security hardening for an Oracle database, the use of the RESOURCE,
DBA, and CATALOG roles are limited and the any permission is revoked. If
necessary, manually assign detailed permission.

Procedure
•Method 1: Assign certain permission of a role to service users based
on the minimum permission principle.
For example, run the following statements to assign permission of the DBA
role to the secguard user:

grant create procedure to secguard;
grant create sequence to secguard;
grant ... to secguard;•Method 2: Create a role, assign certain permission of a role to the
new role based on the minimum permission principle, and assign the role to a
service user.
For example, you can run the following statements for create a role_secguard
role, assign the permission of the DBA role to the role_secguard role, and
assign the role_secguard role to the secguard user:

create role role_secguard;
grant create procedure to role_secguard;
grant create sequence to role_secguard;
grant ¡­ to role_secguard;
grant role_secguard to secguard;