Oracle 19c introduced several enhancements and features aimed at improving manageability for both network services and distributed database environments. These enhancements help DBAs manage complex networks of Oracle databases more efficiently while ensuring security, performance, and automation. Below are key network and database manageability features in Oracle 19c:
1. Enhancements in Network Services
Oracle 19c provides new features and improvements for network configuration, security, and connectivity, making it easier for DBAs to manage distributed databases.
1.1. Secure and Simplified Database Connectivity
Easy Connect Enhancements
Oracle 19c enhances the Easy Connect (EZCONNECT) naming method, reducing the need for cumbersome tnsnames.ora files.
Supports multiple host addresses for High Availability (HA) configurations.
Allows TCP/IP options, making it more flexible and reducing administrative overhead.
Enhanced SQL*Net Client and Server Logging
Improved logging mechanisms provide better diagnostics for connection failures, network timeouts, and handshake issues.
Supports tracing with diagnostic events for deeper visibility.
Oracle Connection Manager (CMAN) Enhancements
Improved scalability and performance for connection pooling.
Supports database traffic filtering, helping DBAs manage large networks securely.
Reduces the number of direct database connections, improving manageability.
ADDM now supports pluggable databases (PDBs) within a multitenant container database (CDB).
Improved diagnostic capabilities help DBAs troubleshoot issues faster.
2.2. Automatic Indexing
Oracle 19c automates index creation, monitoring, and maintenance to improve performance.
Uses AI-based analysis to determine which indexes should be created or dropped.
2.3. Real-Time SQL Monitoring Enhancements
Real-Time SQL Monitoring now includes Automatic Workload Repository (AWR) integration, allowing better visibility of long-running queries across distributed databases.
2.4. Active Data Guard DML Redirection
Oracle 19c allows DML operations on standby databases, automatically redirecting them to the primary database.
This simplifies Active Data Guard setups, reducing manual intervention.
3. High Availability and Scalability Enhancements
Oracle 19c improves resilience and scalability for networks of distributed databases.
3.1. Automatic Reconnect for Data Guard
If a network failure occurs, Oracle 19c automatically reconnects Data Guard processes without DBA intervention.
3.2. Oracle RAC and Grid Infrastructure Enhancements
Grid Infrastructure now supports rapid node addition and removal, making it easier to scale Oracle RAC clusters.
Enhances Cache Fusion performance, reducing network bottlenecks in RAC environments.
3.3. Zero Downtime Grid Infrastructure Patching
Oracle 19c introduces Rolling Patches for Grid Infrastructure, allowing updates without downtime.
4. Improved Security for Database Networks
4.1. Stronger Database Link Security
Stronger password encryption for database links prevents unauthorized access.
New authentication methods support Oracle Cloud and hybrid environments.
4.2. Enhanced Support for TLS 1.2
Oracle 19c enforces TLS 1.2 by default, improving network encryption.
Stronger network encryption algorithms ensure secure connections between Oracle databases.
Conclusion
Oracle 19c introduces significant enhancements that improve network manageability and database operations in distributed environments. Features like automatic indexing, self-healing database links, and secure connection enhancements make it easier for DBAs to manage complex Oracle networks. These improvements reduce manual intervention, improve security, and enhance performance, ensuring a more scalable and resilient Oracle database infrastructure.
In addition to improving the functionality of Network Services with Oracle, we also see some new features that help the DBA manage complex networks of distributed Oracle databases. They are especially useful to the Oracle DBA who has to manage a very large network services installation.
Transparent Application Failover Transparent application failover (TAF)[1] initially worked only with OPS environments, but its functionality has been extended to work with all types of database connections. TAF detects a lost connection and reconnects the user's session to another database.
Ideally, the user does not even notice that his or her connection was temporarily lost.
Transparent application failover (TAF) vs. Application Continuity (AC) in Oracle 19c
Transparent Application Failover (TAF) still exists in Oracle 19c, but Oracle recommends using Application Continuity (AC) as the preferred alternative for better availability and transaction continuity.
TAF in Oracle 19c
TAF provides automatic failover for Oracle Net Services clients in case of a database node failure. It enables reconnection to a surviving database instance without affecting the application, though some transactions may need to be restarted.
TAF Modes in Oracle 19c
SESSION FAILOVER
When a failure occurs, the session is automatically reconnected to a surviving instance.
Any open transactions are lost, but the session remains active.
SELECT FAILOVER
If a query is in progress when a failure occurs, it automatically resumes from the last successful fetch.
Other types of statements (DML, DDL) do not fail over.
NONE
No failover occurs; the client must manually reconnect.
Alternative to TAF in Oracle 19c: Application Continuity (AC)
Application Continuity (AC) is Oracle's recommended solution over TAF.
AC preserves the full transaction state across failovers.
Unlike TAF, AC supports all transaction types, including DML and PL/SQL.
AC works with JDBC, OCI, and UCP (Universal Connection Pooling).
Best suited for mid-tier applications using Oracle RAC, Data Guard, or Autonomous Database.
When to Use TAF vs. Application Continuity?
Feature
Transparent Application Failover (TAF)
Application Continuity (AC)
Failover Type
Select failover (queries only)
Full transaction failover
Supports DML
❌ No
✅ Yes
Supports PL/SQL
❌ No
✅ Yes
Mid-Tier Compatibility
Limited
Fully integrated with JDBC, OCI, and UCP
Recommended for New Deployments?
❌ No (legacy use only)
✅ Yes (preferred solution)
Key Takeaways
TAF is still supported in Oracle 19c, but Oracle recommends using Application Continuity (AC) instead.
TAF is limited to SELECT failover, whereas AC supports full transaction failover.
If you're migrating or deploying a new Oracle 19c system, consider using Application Continuity for seamless failover and better user experience.
Other OEM manageability enhancements
The Oracle Enterprise Manager (OEM) front-end contains the other manageability enhancements: the Management Server and the shared repository. As you know, OEM is a graphical user interface that issues native Oracle commands on your behalf, and edits Oracle parameter files.
Examine the diagram below to see explanations of the two new features within OEM.
Oracle Enterprise Manager enhancementsOracle Enterprise Manager
Oracle Management Server (OMS)
To better support a three-tier architecture, the Enterprise Manager now uses the OMS as a middle tier between the Enterprise Manager console (the first tier), and the distributed databases (the third tier).
Shared Repository: This new feature allows multiple administrators to share the same repository and lets you delegate tasks among database administrators as needed.
The next lesson introduces the new features that improve and simplify security.
[1]Transparent application failover (TAF): A feature in Network to seamlessly move a user’s session from one instance to another when the original instance fails.
