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June 2015

A Database Wordfile…

It is not often that something like the following happens on Google while searching for…

Analysing UKOUG Presenter’s – I Know How You Performed.

This last few days I’ve been analysing how well received previous presentations (since 2006!) have been at the UKOUG tech conferences. It’s interesting to look at the information. I’ve learnt some interesting things about all those well-known-names :-)

Feedback from the Oracle documentation team

feedbackI got some feedback from the Oracle documentation team, based on my recent post.

GUIDs

One of the concerns I raised was about how the GUIDs would be used in different releases of the documentation. Although I don’t like the look of the GUIDs, I can understand why they might be more convenient that trying to think of a neat, descriptive, human readable slug. My concern was the GUID might be unique for every incarnation of the same page. That is, a new GUID for the same page for each patchset, DB version and/or minor text correction. That would make it really hard to flick between versions, as you couldn’t predict what the page was called in each variant.

Oracle Enterprise Manager Cloud Control 12c Release 5 (12.1.0.5) – Just Born

em-12cOracle Enterprise Manager Cloud Control 12c Release 5 (12.1.0.5) was announced a few days ago. I woke up today and checked the interwebs and it’s actually available for download.

I must admit I’m a little nervous about the upgrade. I had a few bad times with upgrades in the early days of Grid Control and Cloud Control and that has left me with a little bit of voodoo lurking in the back of my mind. The last couple of upgrades have been really easy, so I’m sure it will be fine, but that voodoo…

I’ll download it now and do a clean install. Then do a couple of practice upgrades. If all that goes well, I’ll schedule a date to sacrifice a chicken, raise a zombie from the dead to do my bidding, then do the real upgrade.

Indexing and Transparent Data Encryption Part III (You Can’t Do That)

In Part II of this series, we looked at how we can create a B-Tree index on a encrypted column, providing we do not apply salt during encryption. However, this is not the only restriction with regard to indexing an encrypted column using column-based encryption. If we attempt to create an index that is not a […]

Dynamic Sampling

Following on from an OTN posting about dynamic sampling difficulties I had planned to write a blog post about the difference between “not sampling when hinted” and “ignoring the sample” – but Mohamed Houri got there before me.

It’s just worth highlighing a little detail that is often overlooked, though: there are two versions of the dynamic_sampling() hint, the cursor level and the table level, and the number of blocks sampled at a particular level is dependent on which version you are using.  Level 4 at the cursor level, for example, will sample 64 blocks if and only if a certain condition is met,  but at the table level it will sample 256 blocks unconditionally.

CBO Series

About a year ago I came across a couple of useful articles from Stefan Koehler, which is when I added his name to my blog roll. As an introduction for other readers I’ve compiled an index for a series of articles he wrote about the CBO viewed, largely, from the perspective of using Oracle to run SAP. Today I realised I hadn’t got around to publishing it, and there’s been a couple of additions since I first started to compile the list.

Testing 12c CDB Resource Plans and a little bit about OEM Express

Inspired by Sue Lee’s presentation at Enkitec’s E4 conference I decided to re-run my test suite to work out how you can use Database and I/O Resource Manager in Oracle 12.1.0.2.2 to help consolidating databases in the new Multi-Tenant architecture. I should point out briefly that the use of Multi-Tenant as demonstrated in this article requires you to have a license. Tuning tools shown will also require you to be appropriately licensed…

Setup

A new challenge…

After the last 16 years in the contracting and consulting world, for dozens of clients in Australia and other countries around the world, its time for a change of direction.  Whilst doing work with Oracle systems has always been (and continues to be) rewarding, I realised that a lot of the motivation for being at client sites was the sharing of information with developers and DBA’s at those clients so they could get the most out of their Oracle investment.  Similarly, its really cool to speak at conferences to let people explore the Oracle technology in perhaps way they had not thought of, and similarly, blogging about features and idiosyncracies that we stumble upon.  Whatever the medium (and even whatever the technology, whether it be Oracle or otherwise), the concept of an “IT community”, ie, people being keen to share, debate, and discuss has always been one of the things I like about my profession.

12c Parallel Execution New Features: PX SELECTOR

Continuing my series on new 12c Parallel Execution features: I've already mentioned the new PX SELECTOR operator as part of the new Concurrent UNION ALL feature where it plays a key role.