A common frustration for DBAs occurs after identifying a corrupted index or table. You drop the object, expecting the error to vanish, but RMAN backups still fail and Data Guard continues to report a gap. Even though the block is no longer part of a segment, it remains “physically” corrupted in the eyes of theContinue reading “Ghost in the Datafile: Fixing “Empty Block” Corruption in Oracle”
Category Archives: Non classé
ACFS Replication Background Process Stopped After Upgrade to 23ai
If you recently moved from Oracle 19c to Oracle 23ai, you might find your file replication has stopped. Your status shows “Stopped”, and no matter how many times you try to start it, nothing happens. The Problem: The “SCAN” Name In the old version (19c), replication usually connected directly to a specific server’s name orContinue reading “ACFS Replication Background Process Stopped After Upgrade to 23ai”
Deinstalling Oracle Grid Home in Oracle 23ai: Step-by-Step Guide
In Oracle 23ai, the procedure for deinstalling an Oracle Home or Grid Infrastructure Home has not changed compared to previous releases. The standard deinstall utility is still used, and the process remains straightforward. In this article, I will walk through the real procedure I followed to remove an Oracle Grid Home in Oracle 23ai andContinue reading “Deinstalling Oracle Grid Home in Oracle 23ai: Step-by-Step Guide”
Out-of-Place GI Patching Using gridSetup.sh in Oracle 23ai / 26ai
Before performing Out-of-Place Grid Infrastructure (GI) patching, it is strongly recommended to read the following MOS document: Step by Step Out of Place Grid Infrastructure Patching Through gridSetup.sh in Silent Mode(Doc ID 2853839.1) Although this MOS document was written for GI 19.x, it is still largely applicable to Oracle 23ai / 26ai. However, the documentContinue reading “Out-of-Place GI Patching Using gridSetup.sh in Oracle 23ai / 26ai”
Understanding Disk Rebuilds After Replacement in Exadata Compute Nodes
When a disk fails in an Exadata compute node, it should be replaced as soon as possible. Compute node disks are typically configured with RAID-5, which can tolerate only one disk failure. ⚠️ Important: RAID-5 does not create two copies of your data. It stores only one copy, with parity distributed across the other disksContinue reading “Understanding Disk Rebuilds After Replacement in Exadata Compute Nodes”
When the Clustering Factor Strikes: How a “Perfect” Plan Turned into a 9-Second I/O Nightmare
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”
Streamlit : Making Your Enterprise Knowledge Assistant AI Accessible
Last time, I built a working enterprise knowledge assistant in Python using RAG + OpenAI + Chroma. It could read documents, answer questions, and even remember chat history. Today, I’m taking it a step further: giving it a friendly web interface. Instead of typing commands in a terminal, employees can now interact with the assistantContinue reading “Streamlit : Making Your Enterprise Knowledge Assistant AI Accessible”
Building an Enterprise Knowledge Assistant with RAG, OpenAI, and a Vector Database
Many companies have a lot of documents — policies, procedures, meeting notes, and training materials.The problem: this knowledge is often hard to find. In this post, I’ll show how to build a simple Enterprise Knowledge Assistant using LangChain, OpenAI, and a vector database (Chroma).This AI assistant can read your internal files and answer employee questionsContinue reading “Building an Enterprise Knowledge Assistant with RAG, OpenAI, and a Vector Database”
Building a Simple RAG Q&A Assistant with LangChain and OpenAI
I recently explored how to combine LangChain and OpenAI’s GPT models to create an intelligent Retrieval-Augmented Generation (RAG) assistant. This project can read your local documents, store them in a searchable vector database, and answer questions based on your own text . What is RAG? RAG (Retrieval-Augmented Generation) is a powerful technique that combines informationContinue reading “Building a Simple RAG Q&A Assistant with LangChain and OpenAI”
Resizing an ASM Diskgroup on Exadata When OCR/Voting Files Are on It
When you try to shrink an ASM diskgroup that holds Oracle Clusterware files (OCR and voting disks), you may hit errors like: Why it happens Even though Oracle bugs 24568147 and 37688474 mention fixes in newer releases (19.27 RU+), this issue still reproduces in 19.28 and 23.8. The voting files are persisted in the ASMContinue reading “Resizing an ASM Diskgroup on Exadata When OCR/Voting Files Are on It”
Oracle DBA Insights 