Oracle Exascale supports sparse snapshots and fast cloning at the block level. With Cascade Snapshot Cloning, you can create a clone from another clone: Base PDB → Clone A → Clone B → Clone C This is useful when you need many database copies for development, testing, or migration. In this article, we will lookContinue reading “Understanding Cascade Snapshot Cloning in Oracle Multitenant”
Tag Archives: oracle
Exadata Exascale VM Storage is Finally Available
Exadata Exascale VM Storage is officially available in our region! If you are setting up new environments in ExaCC or OCI , Oracle now strongly recommends deploying your VM clusters using an Exascale VM Storage Vault rather than traditional local compute storage. By completely decoupling your VM’s file system from the underlying physical server, thisContinue reading “Exadata Exascale VM Storage is Finally Available”
Ghost in the Datafile: Fixing “Empty Block” Corruption in Oracle
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”
Exadata Snapshot PDB Clone with ACFS
When working with Exadata, there are several ways to create snapshot PDB clones. The main options are: Each one works well, but the best choice really depends on your environment and what you need. Exascale Clone This is clearly the most modern solution. It’s fast, simple, and designed for large environments. But in reality, notContinue reading “Exadata Snapshot PDB Clone with ACFS”
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”
Partitioning in PostgreSQL vs Oracle
A customer who had migrated from Oracle to PostgreSQL several years ago recently reported a serious performance regression. A critical table—now holding over 700 million rows—had become extremely slow when filtering by date. As an DBA, I approached this from an Oracle perspective: partition pruning, local indexes. PostgreSQL partitioning is broadly similar to Oracle’s, butContinue reading “Partitioning in PostgreSQL vs Oracle”
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”
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 