Oracle recommends exclusion of which of the following objects while migrating to ADWC using export/import?

The recommendation to exclude database links (DB Links) during the migration to Autonomous Database on Cloud (ADWC) aligns with the operational context of cloud environments. DB Links are often used to establish a connection between different databases, allowing queries or transactions to span multiple databases. However, when migrating to a cloud service like ADWC, the environment preserves the security and isolation of the cloud architecture.

Migrating DB Links can lead to complications because the references might not resolve in the same context as they did in the on-premises or other environment. This can potentially result in broken references or connectivity issues within the new cloud environment. Instead, it is typically recommended for users to assess their DB Link usage and consider creating new links after migration, which can better align with the cloud's network structure and security policies.

On the other hand, objects like tables, materialized views, and indexes are fundamental components of database structure and queries. They are critical for maintaining data integrity and performance and can be exported and imported without the same level of concern regarding functionality in the new environment. Tables hold the actual data, materialized views allow for more efficient querying and reporting, and indexes improve query performance—all of which should be included during the migration process to ensure the application's functionality remains intact