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 to get Active Data Guard option, you may want different optimizer settings suited for reporting. In non-CDB it’s easy: the…
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. Privilege Analysis Rather than trying with different combination of privileges there is a clever way to do it in 12c with privilege analysis (remember it’s…
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 defined as Object Link. Let’s explain on an example: DBA_HIST_SYSSTAT I’ll talk about all those multitenant internals in DOAG 2016…
By Franck Pachot . In multitenant, there are two goals: consolidation within the same container database and isolation of pluggable databases. I see multitenant consolidation as an extension of schema consolidation. What is not possible in schema consolidation, such as public objects name collision, is now possible with pluggable databases. 10 years ago I administrated on a database with high…
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? I can think of a reason. Let’s say I want to use external authentication for my common users SQL> show parameter prefix NAME…
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 to know whether I’ll get all details in the report or not. There are two main reasons why the most…
By Franck Pachot . In the previous post I’ve explained how to use ‘snapshot copy’ PDB creation for thin provisioning and quick restore of initial state for continuous integration tests. If you don’t have the multitenant option, you need a remote CDB to do it. Here is a way to do the same on only one single-tenant CDB. The idea…
By Franck Pachot . How do you manage your continuous integration tests on the database? You need to restart at the same state for probably a hundred of tests. Recreating the schema and test data takes too long. Oracle is not optimized for DDL. Restoring the database takes too long. Even if you data is small, there is those SYSTEM,…
By Franck Pachot . In multitenant a session can switch from one container to another. There are a few restrictions such as a transaction cannot span multiple containers. But how do sessions parameters behave? It seems that there is a small inconsistency. I was looking at some adaptive plan and SPM behavior (see this tweeter conversation) and played with the…
By Franck Pachot . I have several customers that have cases where Real Application Testing can be interesting, but they don’t use it because it’s an expensive option. Which is why it’s probably the topic listed for OCM 12c exam where I’ve the less experience. And I don’t even know at which level (CDB or PDB) it has to be…
By Franck Pachot . The OCM exam advice says: Be prepared to use the non-searchable documentation during the exam, to help you with correct syntax. I’ve checked that I can find quickly the documentation related with each topic listed. Here it is As in the previous posts, I write that before taking the exam, from only the list of topics,…
By Franck Pachot . I use transportable tablespaces a lot since 8i, here are just a few examples. Same disclaimer here as in the first post of the series: don’t expect to get those posts close to what you will have at the exam, but they cover important points that matches the exam topics. Documentation Information about the exam says:…
