Enable 10046 Tracing for a specific SQL
Available methods to enable 10046 trace are described in My Oracle Support Note 376442.1. You can enable 10046-tracing – on session level (alter session) – for other sessions (e.g. with oradebug, the...
View Article12c online datafile move and ongoing changes
Here is a long answer for a question on our forum about online move: what is internal mechanism to store/keep ongoing changes in that particular datafile while copying is in progress. The short answer...
View ArticleAny reason to change the C## common user prefix?
In 12.1.0.1 the common user prefix was set to C## by an underscore parameter. In 12.1.0.2 it’s a documented parameter and you can change it. But is there any reason for that? I can think of a reason....
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12c Multitenant internals: AWR tables and views
I received a question about multitenant. AWR tables are often raised as an example of Object Links because automatic workload repository is stored only in CDB$ROOT. However, neither the views DBA_HIST…...
View ArticleThe privileges to connect to a container
In Multitenant, there are two ways to connect to a pluggable database. This means that if you want to prevent access to a pluggable database you need to revoke two privileges. Privilege Analysis Rather...
View Article12c Multitenant: PDB spfile parameters for standby database
In multitenant, the spfile parameters at pluggable database level are not stored in the spfile but in the CDB$ROOT table SYS.PDB_SPFILE$ If you open the standby database in read only for reporting,...
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RMAN 12c Push and Pull duplicate explained
Oracle Database 12c introduced the ‘restore from service’ where you can restore and recover by requesting backupsets from the source. With that feature, the duplicate from active can work in the...
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How to check Multitenant Option feature usage
Matching the Feature Usage Statistics to licensed options is not always easy. And once a feature usage is recorded, it is usually stored definitively. Let’s see how the multitenant option is recorded...
View ArticleSingle-Tenant vs. non-CDB: no reason to refuse it
When non-CDB has been declared deprecated, I was a bit upset because multitenant with a lone PDB just looks like an overhead of 3 containers instead of one. But with experience I changed my mind. First...
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APEX Connect 2016 – Day 1 – SQL and PL/SQL
This year the APEX connect conference spans over three days with the first day dedicated to SQL and PL/SQL which are the basement of APEX and its close link to the Database. After the Keynote about...
View Article12c online datafile move and resize
I’ve described in previous posts how the 12c online datafile move works: your session process do the copy and tells other writers (dbwr and direct-path inserts) to write blocks to both files (old one...
View ArticleAdaptive Plans and SQL Baselines
I encountered recently an issue with Adaptive Plan and SPM. Documentations says that it works perfectly together but I remembered a presentation from Nelson Calero at UKOUG TECH15 mentioning strange...
View ArticleStatspack Idle Events
When you don’t have Enterprise Edition + Diagnostic Pack, you cannot use AWR but you can, and should, install Statspack. Statspack is still there, but unfortunately do not evolve a lot. The most...
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Oracle Multitenant feature name
We all know what is the multitenant option: a container database (CDB) with multiple user pluggable databases (PDB). This requires Enterprise Edition plus option. But you can use the same architecture...
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DBA essentials workshop with release Oracle 12c is Available
It’s with pleasure to announced dbi services have upgrade the infrastructure for Oracle DBA essentials workshop. We have migrate the release of Oracle 11g R2 to the latest version Oracle 12c features...
View ArticleMultitenant internals: how object links are parsed/executed
I had a comment on object links internals when creating a sharing=object view on GV$SESSION. Before posting about this specific case, I realized that I’ve never explained how a query on an object link...
View ArticleMultitenant internals: object links on fixed tables
The previous post partly answered to the original question (why an object link to V$SESSION is refreshed only every 30 seconds): recursive queries on shared=object views. Now let’s see what is...
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Windows: Sauvegarde RMAN sur un disque partagé
Dans ce blog, je vais vous expliquer comment exporter les backups RMAN sur un « share disk » appartenant à un Domaine. Assurer la sécurité des données est l’une des tâches principales de...
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Unplugged pluggable databases
When Oracle Multitenant came out in 12c, with pluggable databases, it was easy to draw them as USB sticks that you can plug and unplug to/from your Container Database (CDB). I don’t like this because...
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AUDIT_SYS_OPERATIONS and top-level operation
SYSDBA is powerful. You should use it only when you need to. And you should audit what is done when connected SYSDBA. This is achieved by AUDIT_SYS_OPERATION. But do you have an idea how much audit log...
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