Oracle 19c offers significant advancements tailored for cloud deployment, making it more suitable for modern applications requiring scalability, efficiency, and automation in cloud environments, whereas Oracle 12c is primarily focused on traditional on-premises database management.

Here’s a summary of the key features and improvements in Oracle Database 19c that you mentioned:

1. Automatic Indexing: Oracle 19c introduces automatic indexing, which enhances query performance by automatically creating and managing indexes based on the workload. This feature helps optimize database performance without requiring manual intervention from administrators.

2. Oracle Data Guard Enhancements: Oracle Data Guard ensures high availability and disaster recovery for Oracle databases. Recent improvements have streamlined its management, making it easier and more efficient for organizations to maintain their databases in a failover scenario. An analogy might be likening it to a safety net that not only catches you when you fall but also helps you get back on your feet faster.

3. Multitenant Architecture: This architecture allows a single Container Database (CDB) to host multiple Pluggable Databases (PDBs). This setup optimizes resource usage, simplifies management, and enhances the consolidation of databases, akin to having multiple apartments (PDBs) within a single building (CDB), where shared resources can be efficiently utilized.

4. Automatic In-Memory Population: This feature improves database performance by automatically detecting frequently accessed tables and their associated columns, populating them into the In-Memory column store without manual intervention. This leads to faster data retrieval and improved overall performance.

5. Long-Term Support: Oracle 19c is designated as a long-term support release, meaning it will receive updates, patches, and bug fixes for an extended period compared to other versions. This long-term support ensures stability and security, allowing organizations to plan for the future without needing frequent upgrades.

These features collectively enhance the usability, performance, and reliability of Oracle Database 19c, making it a robust choice for organizations looking to optimize their database management practices.