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Oracle

Clemens Bleile

Creating archived redolog-files in group dba instead of oinstall

By | Database management, Oracle | No Comments

Since Oracle 11g files created by the database belong by default to the Linux group oinstall. Changing the default group after creating the central inventory is difficult. In this Blog I want to show how locally created archived redo can be in group dba instead of oinstall. One of my customers had the requirement to provide read-access on archived redo to an application for logmining. To ensure the application can access the archived redo, we…

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Mouhamadou Diaw

Oracle 19c : Point-In-Time Recovery in a PDB

By | Database Administration & Monitoring, Oracle | No Comments

Point-In-Time Recovery is also possible in a multitenant environment. As in Non-CDB, a recovery catalog can be used or not. In this blog we will see how to recover a dropped tablespace in a PDB. We will also see the importance of using a recovery catalog or not. A PITR of a PDB does not affect remaining PBDs. That means that while doing a PITR in PDB, people can use the other PDBs. In this…

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Jérôme Dubar

ODA X8-2: the new generation

By | Database Administration & Monitoring, Hardware & Storage, Oracle | 2 Comments

Introduction ODA X7-2 marked the maturity of the Oracle Database Appliance evolution, with 3 models suitable for nearly all customers using Oracle databases. The X7-2M was my favorite, with a lots of cores available (and restrainable), enough memory for dozens of databases, and strong storage performance and capacity (with a maximum of 50TB RAW NVMe). And taking up only 1U of space in your rack. Today, 2 years later, Oracle just introduced the new generation…

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Mouhamadou Diaw

RMAN in a Multitenant Environment

By | Database Administration & Monitoring, Oracle | No Comments

The Oracle Multitenant architecture came with Oracle 12c a few years ago. For people usually working with traditional Non-CDB database it might be confusing the first time to do Backup and Recovery with pluggable databases (PDBs) In this document we are trying to explain how to use RMAN backup and recovery in a multitenant environment for an oracle 19c database with 2 pluggable databases. Below the configuration we are using. SQL> show pdbs CON_ID CON_NAME…

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Jérôme Dubar

Useful Linux commands for an Oracle DBA

By | Database Administration & Monitoring, Operation systems, Oracle | 3 Comments

Introduction Oracle & Linux is a great duet. Very powerfull, very scriptable. Here are several commands that make my life easier. These tools seems to be widespread on most of the Linux distributions. watch with diff It’s my favorite tool since a long time. watch can repeat a command indefinitely until you stop it with Ctrl+C. And it’s even more useful with the – -diff parameter. All the differences since last run are highlighted. For…

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Jérôme Dubar

Patching or reimaging your ODA?

By | Database Administration & Monitoring, Hardware & Storage, Operation systems, Oracle | No Comments

Introduction One of the key features of the ODA (Oracle Database Appliance) is the ability to patch the entire stack every three months, the goal being to keep all the components up-to-date. Most of the customers won’t patch so often, but one patch a year is quite a good average. But when comes the time for patching, comes the time for anxiety for the DBA. And it’s totally justified. Why ODA patching can eventually be…

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Pierre Sicot

ORA-01000 and agent13c

By | Database Administration & Monitoring, Oracle | No Comments

Recently I received errors messages from OEM13c saying too many cursors were opened in a database: instance_throughput:ORA-01000: maximum open cursors exceeded My database had currently this open_cursors value: SQL> show parameter open_cursors NAME TYPE VALUE ———————————— ———– —————————— open_cursors integer 300 I decided to increase its value to 800: SQL> alter system set open_cursors=800; System altered. But a few minutes later I received again the same message. I decided to have a more precise look…

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Jérôme Dubar

Why ODA reimaging doesn’t work on the first try?

By | Database Administration & Monitoring, Database management, Oracle | No Comments

Introduction Reimaging an ODA is a good practice for a lot of reasons. To make your ODA cleaner if it’s running for many years and if you patch regularly. To simplify patching because if you’re late you could have to apply multiple intermediate patches to reach the target version. Or simply because you need to change the configuration (for example network configuration) and you want to make things clean, and be sure that future patches…

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