Good link for getting a refresh on the isolation level: http://www.oracle.com/technology/oramag/oracle/05-nov/o65asktom.html
| Isolation Level | Dirty Read | Nonrepeatable Read | Phantom Read |
|---|---|---|---|
| READ UNCOMMITTED | Permitted | Permitted | Permitted |
| READ COMMITTED | – | Permitted | Permitted |
| REPEATABLE READ | – | – | Permitted |
| SERIALIZABLE | – | – | – |
Oracle supports READ COMMITTED and SERIALIZABLE. Oracle doesn’t allow dirty reads(READ UNCOMMITTED). It allows a third isolation level which is READ ONLY. No insert, update, delete can be done in this mode.
