Manageability
Hybrid Read-Only Mode for Pluggable Databases
Administrators can configure pluggable databases (PDBs) to operate in a new mode called hybrid read-only. Hybrid read-only mode enables a PDB to operate as either read-write or read-only, depending on the user who is connected to the PDB. For common users, the PDB will be in read-write mode. For local users, the PDB will be restricted to read-only mode.
Hybrid read-only mode enables you to patch and maintain an application in a safe mode for open PDBs without the risk of local users, including higher privileged ones, interfering with the ongoing maintenance operation of the PDB.
Real-Time SQL Monitoring Enhancements
Real-time SQL Monitoring works independently and concurrently across multiple PDB containers in an efficient manner. SQL statements, PL/SQL procedures and functions, and DBOPs (Database Operations) are monitored at PDB and CDB levels. You can efficiently query SQL Monitor reports across ad-hoc time ranges, DBIDs (internal database identifiers), and CON_DBIDs (CDB identifiers). This data is also accessible through SQL History Reporting.
Additionally, SQL Monitoring data can be exported along with the Automatic Workload Repository (AWR) and imported into another database or container for longer term storage and analysis.
Real-time SQL Monitoring is now supported per-PDB and CDB levels efficiently by default. As a PDBA persona, you can get a more accurate view of the monitored SQL for your application.
SQL Monitoring data can be transported through the AWR framework to a different container or database for longer term storage and offline analysis.
Control PDB Open Order
Administrators can define a startup order or priority for each pluggable database (PDB) where the most important PDBs are started first. The priority is applied to PDB opening order and upgrade order as follows:
- Restoring PDB states when opening the CDB
- Setting PDB states when using the
PDB OPEN ALLstatement - Setting the order for PDB database upgrade operations
- Starting PDBs in an Active Data Guard (ADG) switchover or failover
This feature allows critical PDBs to start and open before less important PDBs, reducing the time for the critical applications to become usable.
Inter-Instance Resource Management
Inter-Instance Resource Management is a preemptive task scheduling and resource management capability that enables fine-grained control over CPU resources across multiple Container Databases, Pluggable Databases, and non-Database processes residing within servers, hosts, or Virtual Machines, in clustered and non-clustered environments. Inter-Instance Resource Management includes upper limits on CPU resource consumption, as well as lower-bound guarantees to enable bursting for multiple Pluggable Databases within a Container and multiple Container Databases on a server, host, or Virtual Machine.
This feature enables effective use of system resources with high-density database consolidation.
Optimized Performance for Parallel File System Operations
In environments that contain many PDBs and require multiple DBMS_FS requests to be processed in parallel, you can update the number OFS_THREADS to increase the number of DBMS_FS requests executed in parallel. This increases the number of worker threads executing the make, mount, unmount, and destroy operations on Oracle file systems in the Oracle database. This will reduce the time needed to execute parallel file system requests in environments with multiple PDBs.
This feature significantly reduces the time required to perform parallel file system requests in consolidation environments containing multiple PDBs.
Read-Only Users and Sessions
You can control whether a user or session is enabled for read-write operations, irrespective of the privileges of the user that is connected to the database. The READ_ONLY session applies to any type of user for any type of container. The READ_ONLY user only applies to local users.
Providing the capability to disable and re-enable the read-write capabilities of any user or session without revoking and re-granting privileges provides you with more flexibility to temporarily control the privileges of users or sessions for testing, administration, or application development purposes. It also gives you a simple way to control the read-write behavior within different parts of an application that are used by the same user or session.