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Sqlplus is my second home: Part 6 – Colorizing sqlplus and terminal output

Jagjeet Singh mentioned that he has built a V2 of his cool SQL Dashboard sqlplus-based monitoring script, which now also shows a nice colored ASH graph output. Yes, right inside sqlplus!

Loving VirtualBox 4.2…

I’m loving VirtualBox 4.2.

I’ve been throwing some RAC, WebLogic and Cloud Control installations on it at home and it’s been coping just fine. I’m especially loving the grouping stuff. I’ve got quite a lot of VMs and scrolling down the list can get a little tiresome. Grouping them and collapsing the group is great!

So far I’ve only see one issue with the groups and I’ve not been able to repeat it. When I dragged one Windows VM (with 2 virtual disks) into a group, both virtual disks were physically moved into the new group sub-directory, but the interface “lost” one of the disks. I went into the Virtual Media Manager, deleted the reference to the “missing” disk, then added it by re-selecting the file from the file system. Everything then worked fine.

Minimum stats

Occasionally I come across complaints that dbms_stats is not obeying the estimate_percent when sampling data and is therefore taking more time than it “should” when gathering stats. The complaint, when I have seen it, always seems to be about the sample size Oracle chose for indexes.

There is a simple but (I believe) undocumented reason for this: because indexes are designed to collate similar data values they are capable of accentuating any skew in the data distribution, which means a sample taken from a small number of leaf blocks can be highly misleading as a guide to the whole index – so Oracle aims for a minimum sample size for gathering index stats.

Private Redo

Following a question on the Oracle Core Addenda pages, here’s a little script to tell you about the sizes of the public and private redo threads currently active in the instance. It’s a minor variation of a script I published in Appendix D (Dumping and Debugging), page 237 to show the addresses of current activity in the various log buffers:

Cloud Control 12cR2 : Is it really release 2?

Oracle Cloud Control 12cR2 is installed and merrily monitoring one of the test 11gR2 databases running on HP-UX. I’ll probably leave it like that until I come back from Oracle OpenWorld. I don’t want to change the entire administration and monitoring infrastructure just as I leave for a couple of weeks.

As I’m re-familiarizing myself with the 12c way of doing things, I’ve been wondering if this really is a full “Release 2″ product, or just 12cR1 with Bundle Patch 2. Not surprisingly, one of my readers asked the same question, pointing out the version 12.1.0.2 does not look consistent with a “Release 2″ product, which would typically be 12.2.0.1.

Courses

I’m working on creating two new courses – one of them about Oracle structures (tables, indexes etc.) the other about Oracle mechanisms (undo, redo etc.). The aim of the courses is to help people do the right thing, avoid the wrong thing, and recognise the difference; the latter, as you might guess, is based loosely on my last book. The courses will probably be ready some time around March next year.

One of the problems of creating the content for courses like this is getting the balance between what people really need to know,  what they already know, and what they would really like to know (or know better); so I thought I’d throw the idea open to the public and ask the question: what would you like to learn (more) about if you came on one of these courses.

Enterprise Manager Cloud Control 12c Release 2 Installation…

I did an EM Cloud Control 12cR2 installation at work yesterday. The database repository was 11.2.0.3 on HP-UX and the middle tier was installed on RHEL 5.8. The installation was pretty much the same as the 12cR1 version. Over the next few days I’ll be testing out some of the features to decide if we can move across to it permanently.

Today I did two run throughs of single server installations on Oracle Linux 5.8 and 6.3. There are a couple of minor differences, but nothing to worry about. You can see what I did here:

The installations are a little small, so they are not too fast, but it’s good enough to test things out.

Cheers

Tim…

VirtualBox 4.2 Released

Hot on the heels of the 4.1.22 release comes Virtual Box 4.2. The downloads and changelog are in the usual places.

It’s a major release with a bunch of interesting new features, so I’ve got an interesting few days ahead while I get to grips with it. You can get an idea about what’s in it here.

Happy upgrading!

Cheers

Tim…

Announcing The Oracle Real World Conference. Attending Oracle OpenWorld 2012? Great, It Happens To Coincide With This Great Event!

BLOG UPDATE 2012-09-21: The conference organizers had to dodge legal bullets from Oracle Corporation for using the word Oracle. So, the name of the conference changed to Oaktable World:

This is just a quick announcement about a great conference hosted by the good folks at Delphix, Miracle and Pythian.

Please visit the Oracle Real World website for session and venue information.

I’ll be offering a session called “SLOB Why, How and What’s It Got To Do With Exadata.” Attendees will learn how to put SLOB to use for their benefit. They might even learn something important about Exadata as an added bonus.

Please follow this link to the website to learn more.

Histogram Generation

This really could be published in the Errata and Addenda of “Cost Based Oracle – Fundamentals”, but it’s more convenient to publish the whole thing here and just add a link to the Errata pages.

In chapter 7, on page 156, I gave an example of the type of SQL that Oracle runs (in the dbms_stats package) to generate a histogram. A sample of the code, and the plan from the 9.2.0.8 tkprof output, is listed below: