OBIEE Which connection pool user NOT to use

Sometime ago I asked why you don’t want to see this:
http://obiee101.blogspot.com/2010/06/obiee-you-dont-want-to-see-this.html
RMN1978 and @lex where the firsts to answer:
If you are using “fixed” users in the connection pool, there are a couple of accounts you never ever should use and a couple you should try to avoid.
Users you should never ever use are the so called system users like SYS, SYSDBA, SYSTEM (Oracle), SA (mssql) etcetera. These users have a specific function on the database and shouldn’t have any operational data. If you really need data owned by these users use a view and ask your DBA to grant you selec only rights.
Users you should try to avoid are so called SCHEMA or OBJECT owners. These users have besides SELECT the right to execute DELETE, UPDATE and INSERT statements. (and sometimes even DROP and CREATE privileges). Always ask you DBA for a SELECT ONLY / READ ONLY account. If you need to execute any functions ask him to grant it to your user (preferably trough a ROLE).
Please Please Please consult your DBA on which Account to use !
Till Next Time