The Oracle Applications Tablespace Model (OATM) -- sometimes also called the Oracle E-Business Suite Tablespace Model) -- organizes the EBS database by object type rather than by products. Prior to OATM, the EBS database had two tablespaces for each product, resulting in hundreds of tablespaces. OATM contains only twelve locally-managed tablespaces. This simplifies management and requires fewer operating system files.
Whether you're already using the Oracle Applications Tablespace Model depends on which version of the E-Business Suite you initially installed. If you started on an older EBS release, you have the option of migrating to the Oracle Applications Tablespace Model.
Is OATM mandatory?
No, it's optional, but we recommend that you use OATM. It's more-efficient and easier to manage. You can use the OATM Tablespace Migration Utility to migrate to the new model.
Can I use OATM with EBS 12.2?
The OATM Tablespace Migration Utility cannot be used after you enable Online Patching in EBS 12.2. If you wish to migrate to OATM, you must do so before you enable Online Patching.
If you do not migrate to OATM, you must continue to manage your tablespaces separately after enabling Online Patching.