Unlocking Peak Performance: A DBA's Guide to Oracle 19c's Automatic Indexing

June 20, 2025

For seasoned Oracle Database Administrators, the release of a new version is a mix of excitement and cautious preparation. Oracle Database 19c, the long-term support release of the 12c family, is no exception. While it boasts a plethora of new features and enhancements, the core responsibility of a DBA remains the same: ensuring optimal performance and stability. One of the most significant advancements in 19c, and a feature that directly addresses a common and time-consuming DBA task, is Automatic Indexing. This article will delve into this game-changing feature, exploring how it can solve performance headaches and streamline your database management workload.

As an Oracle DBA and blogger with over a decade of experience, I've seen my fair share of performance bottlenecks. Inefficient indexing, or a complete lack thereof, is a frequent culprit. Manually identifying and creating the right indexes in a complex and evolving application environment is a relentless task. It requires deep analysis of execution plans, monitoring of high-load SQL, and a constant balancing act to avoid creating redundant or counter-productive indexes. This is where Oracle 19c's Automatic Indexing comes in, offering a powerful, automated solution to this age-old problem.

The Pain Point: The Manual Indexing Treadmill

Before we explore the solution, let's acknowledge the problem. For years, DBAs have relied on a combination of tools and expertise to manage indexes:

AWR (Automatic Workload Repository) and ASH (Active Session History) reports: Analyzing these reports to identify SQL statements with high resource consumption.

SQL Tuning Advisor: Running this advisor to get recommendations for new indexes.

Execution Plan Analysis: Manually examining execution plans to identify full table scans where an index could improve performance.

Third-party tools: Employing various scripts and tools to monitor index usage and identify unused indexes.

While effective, this manual process is reactive and labor-intensive. In a dynamic environment with frequent code releases and shifting data patterns, keeping up with the optimal indexing strategy is a constant battle. The consequences of falling behind are all too familiar: slow application response times, frustrated users, and late-night troubleshooting sessions.

The Solution: Oracle 19c's Automatic Indexing to the Rescue

Oracle 19c introduces a revolutionary approach to index management by automating the entire process. The Automatic Indexing feature, driven by the DBMS_AUTO_INDEX package, continuously monitors your database workload and makes intelligent decisions about creating, validating, and even dropping indexes.

 

Here's a breakdown of how it works and why it's a game-changer for DBAs:

Continuous Learning: Automatic Indexing operates in the background, observing the application's SQL execution patterns. It identifies candidate indexes that could potentially improve the performance of your queries.

Verification and Validation: This is where the magic truly happens. Instead of immediately creating and enabling a new index, Automatic Indexing first creates it as an invisible index. It then tests the impact of this new index on the SQL statements in the workload. This validation process ensures that the new index provides a tangible performance benefit without negatively affecting other queries.

Intelligent Implementation: If the validation proves successful and the new index is deemed beneficial, it is then made visible and available for the optimizer to use. This data-driven approach eliminates the guesswork and risk associated with manual index creation.

Automated Cleanup: The feature doesn't just create indexes; it also identifies and can be configured to drop unused or redundant indexes. This helps to reduce storage overhead and the performance impact of unnecessary index maintenance during DML operations.

Getting Started with Automatic Indexing: A Practical Approach

Implementing Automatic Indexing is surprisingly straightforward. Here’s a high-level overview of the steps involved:

  1. Configuration: The feature is controlled by the AUTO_INDEX_MODE parameter within the DBMS_AUTO_INDEX.CONFIGURE procedure. You can set this to IMPLEMENT to have the database automatically create and enable beneficial indexes, or to REPORT ONLY to simply generate reports of its findings without making any changes. Starting with REPORT ONLY is a prudent first step in a production environment. 
    EXEC DBMS_AUTO_INDEX.CONFIGURE('AUTO_INDEX_MODE', 'REPORT_ONLY');
  2. Monitoring and Reporting: Oracle provides a set of views, such as DBA_AUTO_INDEX_CONFIG, DBA_AUTO_INDEX_EXECUTIONS, and DBA_AUTO_INDEX_REPORTS, that allow you to monitor the activity and recommendations of the Automatic Indexing engine. These reports provide valuable insights into which indexes are being considered and their potential impact.

  3. Gradual Implementation: Once you are comfortable with the recommendations provided in REPORT ONLY mode, you can transition to IMPLEMENT mode. It's advisable to do this in a controlled manner, perhaps initially in a development or test environment, before deploying it in production.

Real-World Benefits and SEO Keywords in Action

By leveraging Oracle 19c Automatic Indexing, you're not just implementing a new feature; you're solving a fundamental performance problem. This directly translates to improved application performance, reduced manual effort, and a more stable database environment.

From an SEO perspective, understanding the key terms users search for is crucial. This article is crafted to rank for a variety of long-tail and high-intent keywords, including:

  • "Oracle 19c performance tuning"
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  • "DBMS_AUTO_INDEX"
  • "Oracle database 19c performance issues"
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Notice how these keywords are naturally woven into the problem-solving narrative of the article. This approach not only attracts the right audience – DBAs and developers struggling with performance – but also provides them with a tangible solution.

Conclusion: Embrace the Automation

Oracle Database 19c's Automatic Indexing is more than just a convenience; it's a paradigm shift in how we approach performance tuning. By entrusting the repetitive and complex task of index management to an intelligent, automated system, DBAs can free up valuable time to focus on more strategic initiatives like database architecture, security, and long-term capacity planning.

If you are currently managing an Oracle 19c database, or are planning an upgrade, exploring and implementing Automatic Indexing should be a top priority. It's a powerful tool that can significantly improve your database's performance and make your life as a DBA a whole lot easier. Stop the manual indexing treadmill and let the database work for you.