martin.bach's picture

Applying PSU in the lab environment

Since the first patch for Oracle 12c has been made available I was of course keen to see how to apply it. For a first test I opted to use my 3 node RAC cluster which is running on Oracle Linux 6.4 with UEK2. This post is not terribly well-polished, it’s more of a log of what I did…

The cluster makes use of some of the new 12c RAC features such as Flex ASM but it is not a Flex Cluster:

[oracle@rac12node3 ~]$ srvctl config asm
ASM home: /u01/app/
Password file: +OCR/orapwASM
ASM listener: LISTENER
ASM instance count: 2
Cluster ASM listener: ASMNET1LSNR_ASM
[oracle@rac12node3 ~]$

My database is a standard 3 node administrator managed build:

rshamsud's picture

Scripts to create AWR reports quickly.

It is easier to create one or two AWR reports quickly using OEM. But, what if you have to create AWR reports for many snapshots? For example, your Oracle support analyst wants you to supply 10 1-hour AWR reports from 10AM to 8PM in a 8 node cluster? That’s about 80 AWR reports to create! Okay, okay, I may(!) be overselling it, but you get the point. It is useful to have a script to create AWR report for all instances for a given range of snapshot IDs. Following scripts are handy:

rshamsud's picture

Oaktable world presentation

I will be hacking RAC internals with few LINUX tools in Oaktable world presentation series, in SFO. Details are available at Oaktable World 2013

Hope to see you there!

rshamsud's picture

RAC Internals: cached sequences and 12c


I blogged about DFS lock handle contention in an earlier blog entry. SV resources in Global Resource Directory (GRD) is used to maintain the cached sequence values. I will further probe the internal mechanics involved in the cached sequences. I will also discuss minor changes in the resource names to support pluggable databases (version 12c).

SV resources

Let’s create an ordered sequence in rs schema and then query values from the sequence few times.

create sequence rs.test_seq order cache 100;
select rs.test_seq.nextval from dual; -- repeated a few times.

Sequence values are permanently stored in the seq$ dictionary table. Cached sequence values are maintained in SV resources in GRD and SV resource names follows the naming convention to include object_id of the sequence. I will generate a string using a small helper script and we will use that resource name to search in the GRD.

rshamsud's picture

Book: Expert Oracle RAC 12c

A quick note, Expert Oracle RAC book co-written by me is available now: Expert Oracle RAC 12c. I have written about 6 chapters covering the RAC internals that you may want to learn :) I even managed to discuss the network internals in deep, after all, network is one of the most important component of a RAC cluster.

martin.bach's picture

Adding a node to a 12c RAC cluster

This post is not in chronological order, I probably should have written something about installing RAC 12c first. I didn’t want to write the tenth installation guide for Clusterware so I’m focusing on extending my two node cluster to three nodes to test the new Flex ASM feature. If you care about installing RAC 12c head over to RAC Attack for instructions, or Tim Hall’s site. The RAC Attack instructions are currently being worked at for a 12c upgrade, you can follow/participate the work on this free mailing list.

The cluster I installed is based on KVM on my lab server. I have used Oracle Linux 6.4 with UEK2 for the host OS. It is a standard, i.e. not a Flex Cluster but with Flex ASM configured. My network configuration is as shown:

oraclebase's picture

Oracle 12cR1 RAC Installation on Windows 2012 Using VirtualBox…

After having a play with Oracle 12c on Windows 8, I decided to give Windows Server 2012 a go. Here is the resulting virtual RAC installation.

As you would expect, much of the process is pretty similar to the 11gR2 RAC installation on Windows 2008.

oraclebase's picture

Oracle Database 12c Virtual RAC Installation on Oracle Linux 6

I finally got my server problems sorted out yesterday, so I was able to do a 12c virtual RAC installation. You can see what I did here:

The setup is pretty much the same as the 11gR2 setup. So there’s no real drama at all.

With the basic installation articles out of the way I can start having a play with the functionality.

oraclebase's picture

My Plans for Oracle 12c RAC Thwarted…

My initial batch of 12c installations resulted in these two articles.

Judging by my web stats, they’ve proved very popular. According to Google Analytics, there are 3-4 active visitors on them pretty much 24×7.

martin.bach's picture

An introduction to Policy Managed Databases in 11.2 RAC

I just realised this week that I haven’t really detailed anything about policy managed RAC databases. I remembered having done some research about server pools way back when came out. I promised to spend some time looking at the new type of database that comes with server pools: policy managed databases but somehow didn’t get around to doing it. Since I’m lazy I’ll refer to these databases as PMDs from now on as it saves a fair bit of typing.

So how are PMDs different from Administrator Managed Databases?

First of all you can have PMDs with RAC only, i.e. in a multi-instance active/active configuration. Before 11.2 RAC you had to tie an Oracle instance to a cluster node. This is why you see instance prefixes in a RAC spfile. Here is an example from my lab cluster:

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