Clemens Bleile

Oracle: Is it possible to setup a system that a client (specific IP address) can only connect to a specific DB-User?

Problem description In a recent consulting assignment I got the following task: A server with a specific IP address (Application server or Oracle Client) should be able to connect to a specific DB-user only. E.g. a single application server(…)

Considerations when backing up from the Oracle Standby Database (Data Guard) with rman to shared storage (NFS)

To reduce load on the Primary DB in a Data Guard configuration you may decide to do your rman backups from the Standby site. A very common approach today is to use NFS as the backup location, especially when using(…)

VirtualBox on Mac Host: High CPU utilization for idle VM

Many people in the IT industry do use VirtualBox as a Type-2 Hypervisor to test software in virtual machines. I’m using it with Vagrant on my Macbook Pro 2019 (Intel with Ventura 13.2. when writing this Blog) to setup testcases(…)

Latency test from Client to Oracle DB: Minimum number of rows fetched in sqlplus and sqlcl

Some time ago I wrote a Blog on how to calculate the network latency fetching a row to a Client from an Oracle database. The tool I used was sqlcl, because it just requires Java and hence no Oracle(…)

Running Intel x86-64 VMs with an Oracle DB on Apple Silicon (ARM)

For testing purposes many IT-people traditionally use Virtual Machines (VMs) on their Laptops (often on Oracle Virtualbox). Since Apple moved to its own processor type (Apple Silicon, i.e. ARM architecture), it’s no longer possible to run VMs based on Intel(…)

datapatch fails when running against an Oracle Container Database because of missing temp files in PDBs

When going to 19.15. a customer hit this error when running datapatch: Unsupported named object type for bind parameter at /u01/app/oracle/product/19.0.0.0/dbhome1915/sqlpatch/sqlpatch.pm line 5849, line 4452. After anlyzing the issue it turned out to be related to what has been documented(…)

Why do we still have HEIGHT BALANCED Histograms and how to get rid of them?

A customer, who is on 19c with his Oracle databases asked me recently why he still has Height Balanced Histograms in his database? E.g. SQL> select histogram, count(*) from dba_tab_columns where histogram <> 'NONE' group by histogram order by 2;(…)

Oracle DBs and ransomware attacks

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(…)

Oracle Database Appliance: Install a DB Release Update manually

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 [root@<node> ~]# odacli create-prepatchreport --dbhome --dbhomeid(…)

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

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(…)