Oracle

Result Cache: when *not* to use it

By Franck Pachot . I encountered recently a case where result cache was incorrectly used, leading to high contention when the application encountered a peak of load. It was not a surprise when I've seen that the function was called(…)

Testing Oracle SQL online

By Franck Pachot . Want to test some DDL, a query, check an execution plan? You need only a browser. And you can copy-paste, or simply link, your test-case in a forum, a tweet, an e-mail, a tweet. Here is(…)

Explain Plan format

By Franck Pachot . The DBMS_XPLAN format accepts a lot of options, which are not all documented. Here is a small recap of available information. The minimum that is displayed is the Plan Line Id, the Operation, and the Object(…)

Unplug an Encrypted PDB (ORA-46680: master keys of the container database must be exported)

By Franck Pachot . In the Oracle Database Cloud DBaaS you provision a multitenant database where tablespaces are encrypted. This means that when you unplug/plug the pluggable databases, you also need to export /import the encryption keys. You cannot just(…)

Spectre and Meltdown on Oracle Public Cloud UEK – LIO

By Franck Pachot . In the last post I published the strange results I had when testing physical I/O with the latest Spectre and Meltdown patches. There is the logical I/O with(…)

Spectre/Meltdown on Oracle Public Cloud UEK – PIO

By Franck Pachot . The Spectre and Meltdown is now in the latest Oracle UEK kernel, after updating it with 'yum update': [opc@PTI ~]$ rpm -q --changelog kernel-uek | awk '/CVE-2017-5715|CVE-2017-5753|CVE-2017-5754/{print $NF}' | sort | uniq -c 43 {CVE-2017-5715} 16(…)

RMAN debugging during catalog import

In this post I would like to share how I have been able to troubleshoot and solve a catalog import issue using RMAN debug function. As we can see, the error message provided by RMAN is not very helpful. oracle@vmtestoradg1:/home/oracle/(…)

ORACLE 11g to 12c RMAN catalog migration

This is a small migration demo of a 11g catalog (RCAT11G) to a new 12c catalog (RCAT12c). Demo databases environments have been easily managed thanks to DBI DMK tool. oracle@vmreforadg01:/home/oracle/ [RCAT11G] sqh SQL*Plus:(…)

Spectre and Meltdown, Oracle Database, AWS, SLOB

By Franck Pachot . Last year, I measured the CPU performance for an Oracle Database on several types of AWS instances. Just by curiosity, I've run the same test (SLOB cached reads)(…)

Running the Oracle Client on a Raspberry Pi

What are the possibilities to use a Raspberry Pi computer as an Oracle client? Besides other things I’ll show a possibility in this Blog to run the fat/thick Oracle Client on a Raspberry Pi! REMARK: All examples below(…)