This wasn’t a theoretical exercise—it was a real-world performance issue that left the database paralyzed.Let’s start with the global stats: The database wasn’t working—it was waiting.Over 90% of the query’s elapsed time was spent on I/O waits, meaning the database was stuck reading data from disk. Step 1: The Execution Plan At first view, theContinue reading “When the Clustering Factor Strikes: How a “Perfect” Plan Turned into a 9-Second I/O Nightmare”
Tag Archives: performance
What Is a Bloom Filter in Oracle Database?
When working with big databases, speed matters. Oracle uses many smart tricks to make things faster. One of these tricks is called the Bloom filter. In this post, I’ll explain what it is and how it helps Oracle database run queries faster — in simple terms! The Problem: Big Tables and Slow Joins Let’s sayContinue reading “What Is a Bloom Filter in Oracle Database?”
Unlocking Performance with Oracle 23AI’s True Cache
Oracle 23AI introduces a groundbreaking feature called True Cache, which provides an in-memory caching layer for frequently accessed data. This significantly improves read performance, especially in environments where quick access to repetitive data queries is critical. However, don’t confuse it with the “In-Memory” feature, as both serve very different use cases. Let’s explore the details.Continue reading “Unlocking Performance with Oracle 23AI’s True Cache”
What should we do if the Flash Cache is degraded in an Exadata cell
Flash cache plays a critical role in Exadata performance. When issues arise, it’s crucial to understand the symptoms and resolution steps. Typically, each flash cache comprises four flash disks. If one flash disk fails, the cell service automatically removes it while continuing to operate with the remaining three disks. In most cases, immediate intervention isContinue reading “What should we do if the Flash Cache is degraded in an Exadata cell”
Oracle DBA Insights 