Oracle Database as our consultants live it every day: installation and patching, upgrades, RMAN backup and recovery, Data Guard, RAC, performance tuning, multitenant, licensing, and engineered systems such as ODA and Exadata.
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 a small list (expecting to grow from your comments) of free online services which can run with an Oracle Database:…
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 Name. You can add columns and/or sections with options, such as ‘rows’, optionally starting with a ‘+’ like ‘+rows’. Some…
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 copy the wallet because the wallet contains all CDB keys. Usually, you can be guided by the error messages, but…
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 SLOB cached reads. Logical reads I’ve run some SLOB cache reads with the latest patches, as well as with only KPTI disabled, and with KPTI, IBRS and IBPB…
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 $NF}’ | sort | uniq -c 43 {CVE-2017-5715} 16 {CVE-2017-5753} 71 {CVE-2017-5754} As I did on the previous post on AWS, I’ve run quick tests on the Oracle Public…
In this post I would like to share how I have been able to troubleshoot and solve a catalog import issue using RMAN debug function. As we can see, the error message provided by RMAN is not very helpful. oracle@vmtestoradg1:/home/oracle/ [RCAT12C] rman catalog rcat/manager Recovery Manager: Release 12.2.0.1.0 connected to recovery catalog database RMAN> import catalog rcat/manager@RCAT11G; Starting import catalog…
This is a small migration demo of a 11g catalog (RCAT11G) to a new 12c catalog (RCAT12c). Demo databases environments have been easily managed thanks to DBI DMK tool. oracle@vmreforadg01:/home/oracle/ [RCAT11G] sqh SQL*Plus: Release 11.2.0.4.0 oracle@vmtestoradg1:/home/oracle/ [RCAT12C] sqh SQL*Plus: Release 12.2.0.1.0 Current configuration Displaying the list of databases registered in the RCAT11g catalog. SQL> select instance_name from v$instance; INSTANCE_NAME…
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) now that Amazon has applied all Spectre and Meltdown mitigation patches. I must admit that I wanted to test this on the Oracle Cloud first. I’ve updated a…
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 were made with an Rasperry Pi 3 and the OS Raspbian, which can be downloaded from https://www.raspberrypi.org/downloads First of all what’s possible…
By Franck Pachot . This is a small demo I did when I’ve found a database password file (orapw) lying around in /tmp with -rw-rw-rw- permissions, to show how this is a bad idea. People think that the orapw file only contains hashes to validate a password given, and forget that it can be used to connect to a remote…
By Franck Pachot . In the previous post https://www.dbi-services.com/blog/12c-multitenant-internals-pdb-replay-ddl-for-common-users I’ve done some DDL on a common user to show how this is replayed later for PDBs that were not opened at that time. But what happens when one of the DDL fails on one PDB? PDB$LASTREPLAY In the last post, the C##USER1 common user was created and all pluggable databases…
By Franck Pachot . In multitenant, you can create common Users, Roles, and Profiles. You create them in CDB$ROOT, with the CONTAINER=ALL clause (which is optional because it is the only possible value when connected to CDB$ROOT) but they are visible to all containers. As the goal of multitenant is to avoid to duplicate common metadata to all containers, You…
