Automatic In-Memory
Oracle In-Memory was introduced in version 12c as a way to accelerate performance by storing columnar-compressed database segments into memory.
In 18c, Oracle furthers development on In-Memory by introducing Automatic In-Memory (AIM).
AIM works by building a heat map of the in-memory enabled objects and makes room for those objects that are more frequently accessed. AIM will only kick in when there is not enough space to add another object to the memory store.
SQL Cancel
In past versions of Oracle whenever a database administrator needed to cancel a SQL query, the session that was running the SQL had to be killed.
This meant the session had to be removed from the database and a new connection would have to be initiated. Now in Oracle 18c the SQL statement itself can be canceled and rolled back.
Schema Only Accounts
In the past, a schema could be more closely associated as a user account that owned those objects. But this also meant that a user could log in to the schema and have control over those objects.
With schema only accounts, users cannot directly login to the schema. These types of accounts can be created without a password and can be assigned permissions or granted roles just like a regular user account.
Integration with Microsoft Active Directory
Starting with Oracle 18c, the database can authenticate and authorize users from Microsoft’s Active Directory, without the need for any intermediate directories.
This is a new, simpler way to integrate with Active Directory. In previous versions, intermediary software such as Oracle Enterprise User Security was required to achieve integration.
This new feature is named Centrally Managed Users (CMU) and allows you to manage authorization for Active Directory users to access the Oracle database. Active Directory account policies are enforced by the Oracle database when users are authenticated in this manner.
