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12c Release 2

You may still need gcc when patching Oracle Database 12.2

I have previously written about changes in the Oracle 12.2 preinstall RPM and how gcc is no longer part of the dependencies list. As was pointed out to me, this shouldn’t be necessary anymore, according to the 12.2 Linux Database Installation Guide. Check the blue note for a statement indicating that gcc and gcc-c++ aren’t needed for Grid Infrastructure, nor for the RDBMS software.

I have applied patch 27100009 (January 2018 Release Update 12.2.0.1.180116) on my 2 node RAC system in the lab, and found out that this is partially true :) You may or may not encounter this issue in your environment, see below.

OSWatcher, Tracefile Analyzer, and Oracle Restart 12.2

You are about to read the second part of this mini-series on TFA and Oracle 12.2. In the previous article I wrote about TFA and Oracle 12.2 single instance. In this short article I am going to have a look at TFA in a 12.2 Oracle Restart environment before rounding it up with an investigation into a full-blown RAC installation in part 3.

Summarising the first part I can only say that I am very happy that we now get TFA as part of the standard installation. Running it in daemon mode provides some great insights, and even if you did not upgrade the installation to “MOS-TFA”, you have a very fine tool for Oracle troubleshooting at your disposal.

Summary of the environment

My environment is largely the same as last time, except the machine name changed to server4 and I have additional storage for use with ASM.

OSWatcher, Tracefile Analyzer, and Oracle 12.2 single instance

I have previously written about TFA, OSWatcher et all for Oracle 12.1. Since then, a lot of things have happened and I had an update for 12.2 on my to-do list for far too long. Experience teaches me that references to support notes and official documentation get out of date rather quickly, so as always, if you find anything that changed please let me know via the comments section and I’ll update the post.

This is going to be a 3 part mini-series to save you having to go over 42 pages of text … In this first part I’m going to have a look at single instance Oracle. In part 2 I’ll have a look at Oracle Restart environments, and finally in part 3 I’ll finish the series by looking at a 12.2 RAC system.

Little things worth knowing: redo transport in Data Guard 12.2 part 2

In the first part of this article I looked at a number of views and some netstat output to show how redo is transported from the primary database to its standby systems. The long story short is that TT02 (“async ORL multi”) was found sending redo to CDB3 asynchronously whilest NSS2 (“sync”) transferred redo to the synchronised target – CDB2. Unlike v$dataguard_process wanted me to believe, it really wasn’t LGWR sending redo over the network.

In this little article I would like to show you how the standby databases CDB2 and CDB3 receive redo and how you can map this back to the primary database, closing the loop.

Little things worth knowing: redo transport in Data Guard 12.2 part 1

I have researched Data Guard redo transport quite a bit, but so far haven’t really blogged about some of the details that I have worked out. This is what I am trying to do in this post.

In order to have a somewhat meaningful setup, I created a Data Guard configuration with 1 primary and 2 standby databases. They all reside on my lab (virtual) machines:

Truncated CTAS statements seem to be no longer shortened

Many bloggers have already discussed that Oracle can truncate the text of a “create table as select” statement to 20 characters depending on your version and patch level. This can be a problem in case a CTAS statement is a resource hog, yet you don’t see the SQL text that is needed for troubleshooting. A quick search on My Oracle Support reveals this can happen on 11.2.0.4, 12.1.0.1 and 12.1.0.2 systems unless patched of course. This has been bugging me for quite some time now, and merits a blog post.

Reproducing the offending behaviour

Oracle has provided a number of patches over time to fix this undesirable short-cutting of the SQL text. I wanted to reproduce the issue on 12.1 to demonstrate the effect. To my shame I have to admit that since 12.2 has come out I have somewhat neglected my 12.1 lab system. It was quite a bit out of date, which was useful for this blog post as it will turn out.

Changes to the Oracle preinstall RPMs in OL 7.3 and OL 7.4

For quite some time now Oracle has documented the use of the so-called preinstall RPMs to prepare Oracle Linux for the installation of the Oracle database software. I think that’s a great idea if the settings applied by the RPM fit your environment. If I find the time, I’ll write a blog post about what it does specifically in a little while. It definitely fits my lab environment, and I regularly kickstart my OL 7 VMs specifying the preinstall RPM in the %packages section.

When upgrading the current base image from Oracle Linux 7.2 to Oracle 7.4/Oracle 12.2 I noticed a few changes to the preinstall RPMs.

12.2 New Feature: the FLEX ASM disk group part 5

Some time ago I had a very interesting twitter conversation after publishing the first part of this series. The question was whether using ASM templates, which admittedly exist since Oracle 10.1, didn’t provide similar functionality as Flex Disk Groups. In other words, wouldn’t using ASM templates allow you to have high redundancy files on normal redundancy disk groups anyway?

This question has been answered by Alex Fatkulin in a blog post some time ago. In this post I would like to replay his test with my 12.2 setup. Initially I had hoped to compare the approach using ASM templates with the Flex ASM Disk Group but the post has become too long again … The actual comparison will be done with the next instalment of the series.

12.2 New Feature: the FLEX ASM disk group part 4

Flex Disk Group Properties

In the previous 3 parts I shared my investigation into ASM Flex Disk Groups, Quota Groups, File Groups, and how Quota Groups actually enforce space limits. What I haven’t discussed yet was changing properties of a File Group and the effects thereof. Properties I have in mind are related to the protection level, as discussed in the official documentation-Automatic Storage Management Administrator’s Guide, Administering Oracle ASM Disk Groups. There are of course other properties as well (and you’ll find a link to all of the modifiable properties later in this post), but they are out of scope for this investigation.

12.2 New Feature: the FLEX ASM disk group part 3

In the previous 2 parts of this mini series I introduced the Flex ASM disk group and two related concepts, the Quota Group and File Group. In what should have become the final part (but isn’t) I am interested in checking whether quotas are enforced.

(Un)fortunately I have uncovered a few more things that are worth investigating and blogging about, which is why a) this isn’t the last post and b) it got a bit shorter than the previous two. Had I combined part 3 and 4 it would have been too long for sure … BTW, you can navigate all posts using the links at the very bottom of the page.

Are quotas enforced?

The purpose of the Quota Group is … to enforce quotas on a disk group, much like on a file system. This is quite interesting, because you now have a hard limit to which databases can grow within a disk group even for non-CDBs.