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November 2018

opatch investigations

This blogpost is about opatch and how to obtain information about the current oracle home(s), and how to obtain information about the patches to be applied.

Patches that can be applied using opatch are provided by oracle as zip files which have the following naming convention:
p[patchnumber]_[baseversion]_[platform]-[architecture].zip. The patch normally contains an XML file called ‘PatchSearch.xml’ and a directory with the patch number. Inside the patch number directory there is a README.txt which is lame, because it says ‘Refer to README.html’, and a README.html that contains the readme information that is also visible when the [README] button for this patch is selected in MOS.

Super Lock an Oracle Database

I started this blog post a few weeks ago and kept adding to it from time to time but I have been incredibly busy helping people secure data in their Oracle databases that it has taken a long time to....[Read More]

Posted by Pete On 14/11/18 At 02:20 PM

March 2019 – New Webinar Dates Announced for “Oracle Indexing Internals and Best Practices”

I’m very excited to announce two new Webinar events for my acclaimed “Oracle Indexing Internals and Best Practices” training event, running in March 2019 !! For details of all the extensive content covered in the webinars, please visit my Indexing Seminar page. The webinars will run for 4 hours each day, spanning a full week period (Monday […]

Index Splits – 3

This is stored only for reference, and in case anyone wants to wade through the details. It’s the redo log dump from the 90/10 index leaf block split test from the previous blog posts running on 11.2.0.4 on Linux. The first part is the full block dump, the second part is an extract of the Record and Change vector headings with the embedded opcode (opc:) for the undo records in the redo vectors, and a tiny note of what each change vector is doing.

Ansible tips’n’tricks: executing related tasks together

I have recently written an ansible playbook to apply one-off patches to an Oracle Home. While doing this, I hit a little snag that needed ironing out. Before continuing this post, it’s worth pointing out that I’m on:

$ ansible --version
ansible 2.6.5

And it’s Ansible on Fedora.

Most likely the wrong way to do this …

So after a little bit of coding my initial attempt looked similar to this:

Sizing Up #SQLPass Summit 2018 After the Fact

This is my third time attending PASS Summit and second time as a speaker.  I applaud the PASS organizers, the community, the volunteers, the sponsors and the attendees for another incredible event.  In less than four days, I came home and tried to isolate one defining moment from the event and it was impossible to do so.

opatch versions

This blogpost is about oracle’s patching tool for the database and grid infrastructure: opatch. I personally have a love/hate relationship with opatch. In essence, opatch automates a lot of things that would be very error prone if it were to be done by hand, which is a good thing. However, there are a lot of things surrounding opatch that I despise. An example of that is the version numbering of opatch itself.

Versions and more versions

To jump into the matter directly: versions. I don’t understand why this has to be this complicated. I would even go as far as saying that somebody needs to step in and clean this up.

Oracle LIKE predicate and cardinality estimations

A new blog post on the Databases at CERN blog about the optimizer estimations with a LIKE predicate: https://db-blog.web.cern.ch/blog/franck-pachot/2018-11-oracle-predicate-and-cardinality-estimations.

Or why the cardinality estimation here is 1346 objects like ‘DBA_OBJECTS’ rather than 2:

Scripts for Drilling Down Into Unknown Optimizer Changes

When I delivered my Advanced Oracle SQL Tuning training last week, I jumped into a free-form demo to show that the PARALLEL hints don’t really force anything other than adjusting the cost of parallelizable operations for CBO evaluation as usual. If a serial plan (or branch) still has a lower cost than the respective parallel processing cost, then serial execution would be used there. But when demoing this, I got a surprise.

Scripts for Drilling Down Into Unknown Optimizer Changes

When I delivered my Advanced Oracle SQL Tuning training last week, I jumped into a free-form demo to show that the PARALLEL hints don’t really force anything other than adjusting the cost of parallelizable operations for CBO evaluation as usual. If a serial plan (or branch) still has a lower cost than the respective parallel processing cost, then serial execution would be used there. But when demoing this, I got a surprise.