Oracle 12c

How to check Multitenant Option feature usage

By Franck Pachot . 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 there.

RMAN 12c Push and Pull duplicate explained

By Franck Pachot . 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 opposite way: instead of asking(…)

12c Multitenant: PDB spfile parameters for standby database

By Franck Pachot . 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, which is one reason(…)

The privileges to connect to a container

By Franck Pachot . 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.

12c Multitenant internals: AWR tables and views

By Franck Pachot . 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$ROOT. However, neither the views DBA_HIST... nor the tables WRH$_... are(…)

Any reason to change the C## common user prefix?

By Franck Pachot . 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?(…)

12c online datafile move and ongoing changes

By Franck Pachot . 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.

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 package DBMS_MONITOR or DBMS_SYSTEM) What is not(…)

SQL Plan Directives strikes again

By Franck Pachot . 12c SQL Plan Directives, a side effect, a bad application design, a bug... and the occasion to show how to quickly troubleshoot. An application has long response time since 12c migration. No blind guesses, no reason(…)

awrrpt and spreport in multitenant

By Franck Pachot . Yesterday I was giving my 'Interpreting AWR Reports' Prezi at Oracle Midlands. There is a point where I explain that I always check the 'Captured SQL account for ...% of Total DB Time (s)' in order(…)