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Clemens Bleile

Clemens Bleile

Oracle DBs and ransomware attacks

By | Oracle | No Comments

By Clemens Bleile I had a discussion with a customer recently about the risk of running into an issue with ransomware encrypting data of Oracle databases. Just to quickly recap on what ransomware is: Wikipedia: Ransomware is a type of malware from cryptovirology that threatens to publish the victim’s personal data or perpetually block access to it unless a ransom is paid. While some simple ransomware may lock the system without damaging any files, more…

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Clemens Bleile

Oracle Database Appliance: Install a DB Release Update manually

By | Oracle | No Comments

By Clemens Bleile Recently I upgraded an ODA X7-M from 19.12. to 19.13. After the dcs-, server- and storage-upgrade several databases on the machine had to be patched from 19.9. to 19.13. The [[email protected]<node> ~]# odacli create-prepatchreport –dbhome –dbhomeid <home-id> -v 19.13.0.0.0 went through without reporting an issue, but during the [[email protected]<node> ~]# odacli update-dhome -i <home-id> -v 19.13.0.0.0 -f I got an error “DCS-10001:Internal error encountered: null.”: [[email protected]<node> ~]# odacli describe-job -i “<Job-Id>” Job…

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Clemens Bleile

Oracle Database Appliance (ODA): Adjusting to the new ORACLE_BASE-setting from 19.11. onwards

By | Oracle | No Comments

By Clemens Bleile From Oracle Database Appliance (ODA) version 19.11. onwards the ORACLE_HOMEs and ORACLE_BASE will be created on ACFS, i.e. take space from an ASM-diskgroup instead of taking filesystem space from /u01. See this blog concerning details. If the ODA has been upgraded from a release < 19.11. to 19.11. or newer, then you usually have diag- and admin-data in 2 ORACLE_BASE-locations: /u01/app/oracle for databases created before migrating to ODA 19.11. or newer and…

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Clemens Bleile

opatch hangs while patching OEM 13.4. concerning the log4j-vulnerability

By | Oracle | No Comments

By Clemens Bleile To address the log4j-vulnerability I recently had to fix the Oracle Enterprise Manager 13.4.-installation for a customer. REMARK: Please check the following link for details concerning the log4j-vulnerability and how Oracle is affected: alert-cve-2021-44228 and the following MOS Notes: – Impact of December 2021 Apache Log4j Vulnerabilities on Oracle Products and Services (CVE-2021-44228, CVE-2021-45046) (Doc ID 2827611.1) – Impact of December 2021 Apache Log4j Vulnerabilities on Oracle on-premises products (CVE-2021-44228, CVE-2021-45046) (Doc…

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Clemens Bleile

Script to calculate the network latency between the application and the Oracle DB-server

By | Oracle | 2 Comments

By Clemens Bleile Network latency is crucial for applications, especially if lots of “row by row”-processing (some call it “slow by slow”-processing) is used by the application or if lots of data is transported between the database and the application. If there’s lots of data to be transported between the database and the application then increasing the fetchsize may help to improve the performance and throughput. But this is not the aim of this blog….

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Clemens Bleile

MacOS: Reduce fan noise when using Microsoft Teams

By | MS Teams | No Comments

The Laptop I’m using for the business is a MacBook Pro, model 2019 (2.6 GHz 6-Core Intel Core i7). I’m thankful to be able to choose the Hardware and OS of my business laptop at dbi services. We have collegues using Laptops with Windows, some use Laptops with Linux and a considerable amout of people use MacBooks. However, what annoyed me with my Laptop were MS Teams meetings when the fan noise went up considerably….

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Clemens Bleile

Exadata Cloud at Customer: Considerations for Backup & Recovery

By | Oracle | No Comments

Working in a project where the customer migrates from an on-premises environment to Exadata Cloud at Customer provides insights about the decisions to take and what to consider when using the Exadata Cloud at Customer environment. In a series of blogs I want to talk about the different aspects when going to the Exadata Cloud at Customer (ExaCC). Let’s start with the most important task a DBA is responsible for: Backup & Recovery. REMARK: This…

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Clemens Bleile

ODA 19.11.: ORACLE_HOMEs on ACFS

By | Oracle | 4 Comments

Introduction Beginning with Oracle Database Appliance (ODA) 19.11. the ORACLE_BASE and ORACLE_HOMEs are created on ACFS. That’s good news, because there is much more space on ASM than on the internal disks, i.e. no space issues with /u01 anymore. So how does it work? ORACLE_BASE and ORACLE_HOME on ACFS When installing an ODA from scratch then ORACLE_BASE and ORACLE_HOME are already on ACFS. See an example of a freshly installed ODA X8-2M: [[email protected] ~]# odacli…

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Clemens Bleile

Creating an Oracle Snapshot Copy PDB on top of ASM

By | Oracle | No Comments

Creating a snapshopt copy Pluggable Database (PDB) on top of Automatic Storage Management (ASM) is not possible, because you need to have a filesystem which supports sparse files. According the following MOS-Note sparse files are supported on Automatic Storage Management Cluster File System (ACFS) since 12.2.: 12.2 Oracle ACFS Sparse Files Enhancements (Doc ID 2200264.1) However, I thought it is more fun to create a PDB Snapshot Copy on a XFS-filesystem, which I wanted to…

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Clemens Bleile

Parameterized Views with SYS_CONTEXT in Oracle. How can the optimizer peek values?

By | Oracle | No Comments

There was a dicsussion a couple of years ago about a mssing feature in Oracle that the Optimizer is not peeking values when SYS_CONTEXT is being used in a predicate. I.e. specifically when using SYS_CONTEXT in Views to simulate passing parameters to views. See the following links concerning this topic: https://connor-mcdonald.com/2016/10/20/taking-a-peek-at-sys_context https://blog.jooq.org/2016/10/20/be-careful-when-emulating-parameterised-views-with-sys_context-in-oracle https://community.oracle.com/ideas/15826 E.g. take the example of Connor McDonald here: [email protected]@PDB1> create table t ( x varchar2(10), y char(100)); Table created. [email protected]@PDB1> [email protected]@PDB1> insert…

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