12c Release 1

martin.bach's picture

Recovering a standby over the network in 12c

Another one of the cool but underrated features in 12c is the possibility to recover a physical standby over the network with one line in RMAN.

Why do you need to perform this activity? Assume someone really clever created a segment “nologging” and the database was not in force logging mode. This operation cannot be replicated by redo apply on the standby, and you are bound to have a problem. Or, in my case, I had the standby shut down in my lab environment (intentionally) and created a few PDBs on my primary. For some reason I lost an archived redo log. This would of course not happen in a production environment, but my lab VM is limited when it comes to space and I may have moved my backup to a USB disk that I didn’t bring along.

martin.bach's picture

Interesting GNS anomaly in 12.1.0.1.2 RAC

I was encountering an interesting anomaly with my 12.1.0.1.2 RAC cluster based on Grid Naming System. I have written about the setup here.

martin.bach's picture

Interesting GNS anomaly in 12.1.0.1.2 RAC

I was encountering an interesting anomaly with my 12.1.0.1.2 RAC cluster based on Grid Naming System. I have written about the setup here.

martin.bach's picture

Runtime Load Balancing Advisory in RAC 12c-addendum

A reader asked an interesting question yesterday with regards to the previous post on the subject: where did you get your service metrics from when you queried v$servicemetric-PDB or CDB$ROOT?

I queried the PDB, but this morning repeated the test to make sure the results are consistent, and they are. This is definitely something you’d hope for: you should not have different results in the same v$-view depending on the container you execute your query in for a given CON_ID.

During testing I noticed something interesting though. I queried gv$servicemetric but did not limit the result to the service I wanted to test with (FCFSRV). Here is the query against gv$servicemetric while the system was idle.

martin.bach's picture

Runtime Load Balancing Advisory in RAC 12c-addendum

A reader asked an interesting question yesterday with regards to the previous post on the subject: where did you get your service metrics from when you queried v$servicemetric-PDB or CDB$ROOT?

I queried the PDB, but this morning repeated the test to make sure the results are consistent, and they are. This is definitely something you’d hope for: you should not have different results in the same v$-view depending on the container you execute your query in for a given CON_ID.

During testing I noticed something interesting though. I queried gv$servicemetric but did not limit the result to the service I wanted to test with (FCFSRV). Here is the query against gv$servicemetric while the system was idle.

martin.bach's picture

Runtime Load Balancing Advisory in RAC 12c

This is a follow-up on yesterday’s post about services in the new 12c database architecture. After having worked out everything I needed to know about TAF and RAC 12c in CDBs I wanted to check how FCF works with PDBs today. While investigating I found out that the Runtime Load Balancing Advisory does not seem to work as expected in some cases. But I’m getting ahead of myself. First of all, here is my test case:

  • Oracle Linux 6.4 x86-64
  • Grid Infrastructure 12.1.0.1.2, i.e. January 2014 PSU applied
  • RDBMS 12.1.0.1.2, likewise patched with the January PSU
  • A CDB with just 1 PDB for this purpose, named DEMOPDB
  • Service FCFSRV is used

Service setup

The service is specifically created to connect against the PDB:

martin.bach's picture

Runtime Load Balancing Advisory in RAC 12c

This is a follow-up on yesterday’s post about services in the new 12c database architecture. After having worked out everything I needed to know about TAF and RAC 12c in CDBs I wanted to check how FCF works with PDBs today. While investigating I found out that the Runtime Load Balancing Advisory does not seem to work as expected in some cases. But I’m getting ahead of myself. First of all, here is my test case:

  • Oracle Linux 6.4 x86-64
  • Grid Infrastructure 12.1.0.1.2, i.e. January 2014 PSU applied
  • RDBMS 12.1.0.1.2, likewise patched with the January PSU
  • A CDB with just 1 PDB for this purpose, named DEMOPDB
  • Service FCFSRV is used

Service setup

The service is specifically created to connect against the PDB:

martin.bach's picture

RAC and Pluggable Databases

In preparation of the OUGN Spring Seminar and to finally fulfill at least a part of my promise from July I was getting ready to research RAC, PDBs and services for my demos. It turned out to become a lot more interesting than I first assumed.

RAC and Multi-Tenancy

So the first attempt to really look at how this works has started with my 2 node cluster where I created a RAC database: RAC12C, administrator managed with instance RAC12C1 and RAC12C2. The database is registered in Clusterware. Clusterware and RDBMS are patched to the January PSU, i.e. 12.1.0.1.2.

martin.bach's picture

Applying GI PSU 12.1.0.1.2 in the lab

In my previous posts about the first RAC Grid Infrastructure Patchset I document a few issues I encountered that were worth noting. But where things work as advertised I am more than happy to document it too. In a way, the January 2014 GI PSU works as you’d hope it would (at least in my lab for my 2 node cluster). Well-almost: if you have a non 12.1 database in your environment you might encounter this.

UPDATE: You might want review some additional information with regards to datapatch.

Admittedly it’s taken from an Oracle Restart (i.e. non cluster) environment but I can’t see this not happening in RAC:

martin.bach's picture

Applying PSU 12.1.0.1.1 to Oracle Restart

I was actually hoping I had already written enough about applying the PSU for 12.1.0.1.0 but today I tried to apply the patch to my Oracle Restart home in my lab VM and guess what-it wasn’t as automatic as I thought.

I must have performed the classic copy & paste error and applied the patch to the GRID_HOME only. Please don’t do this! The README clearly states you can but if you do, you will run into this mess. At the time of writing there was no hit for the error on my favourite search engine, hence this post. If you see this on a real database and not on your personal lab VM you should of course consult support what to do. This is for educational purposes only, so to say.

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