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January 2014

Delphix success and Paternity Leave

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photo by Steve Jurvetson

I’m off on for a couple weeks for paternity leave! Actually started on Saturday night a week ago with the beautiful, stressful, exciting, fast birth of our second son. What a gift. :)

Travel

I’m going to be in Denver next week for the RMOUG Training Days – so I’ve just received an email asking me if I could stay on a couple of days and visit someone fairly close by while I’m in the area. It’s not the first time that I’ve had a last minute request like this; unfortunately I tend to book my flights weeks, and sometimes months, in advance – usually at a good price but with a hefty cancellation penalty (like, no refund), so not possible this time.

However, I’m going to be speaking at ODTUG Kscope 14  (my name’s not visible on the agenda yet) and I’m just about to book the flights but, in view of the email, I thought I’d wait a few days and let people know where I’m heading in case someone wants me to spend a couple of days on-site in Seattle at the end of the week commencing 21st June.  Email me if you’re interested:  jonathan@jlcomp.demon.co.uk

 

Oracle Linux UEK3, Huge Pages and VMware

For those of you using Oracle Linux with UEK3, here are a couple of important blog posts that may have passed you by.

Thanks guys!

Cheers

Tim…

Massive tablespace fragmentation on LMT with ASSM

I have been asked to investigate another interesting problem worth writing about. It’s worth mentioning here because it deals with a problem I believed to have long since been solved: tablespace fragmentation. However, in this case it was a locally managed tablespace (LMT) with Automatic Segment Space Management (ASSM) enabled. It should be difficult to have fragmentation on one of these, but as you will see it is not impossible.

So the story started innocently enough with an ORA-01653 while shuffling around subpartitions to another tablespace:

Expert

A recent “Hot topics” email from Oracle support listed the following bug as one which had recently been updated:


17727676 OPTIMIZER HINT IGNORED  WHEN USING INVISIBLE INDEXES

Since the optimizer is one of my pet topics I thought I’d take a quick look at what it said – and found this heart-warming introduction;


Hdr: 17727676 11.2.0.3.0 RDBMS 11.2.0.3.0 QRY OPTIMIZER PRODID-5 PORTID-226
Abstract: OPTIMIZER HINT IGNORED WHEN USING INVISIBLE INDEXES
*** 11/03/13 03:46 am ***

PROBLEM:
--------
Based on a blog article from the international recognized Oracle Expert Jonathan Lewis ...

If it’s on MoS surely it’s just got to be true!  (Yes, I know I’ve said the opposite in the past – but it’s definitely right some of the time)

Pagination

I was involved in a thread on Oracle-L recently started with the question: “How many LIOs is too many LIOs”. Rather than rewrite the whole story, I’ve supplied a list of links to the contributions I made, in order – the final “answer” is actually the answer to a different question – but travels an interesting path to get there.#

crsd.bin core dumps

Core dump issues sometimes can be notoriously difficult to troubleshoot. I've got a call this morning from one of my customers saying that after a power outage Grid Infrastructure is not able to fully come up on some nodes on their Exadata cluster. After further examining the situation it turned out that crsd.bin binary is simply core dumping upon start up.

Troubleshooting Grid Infrastructure startup issues when nothing is core dumping sometimes could be a chore so what could be more fun when it's not able to fully start due to a major daemon core dumping?

One of the useful things to do when a binary core dumps is to get a stack trace to see which function raised the exception (you can examine the core file the gdb, for example, in order to do that). Let's see what the stack trace holds for us:



Core was generated by `/u01/app/11.2.0.3/grid/bin/crsd.bin reboot'.
Program terminated with signal 6, Aborted.

Captain Support and TeamViewer

I recently read the news that LogMeIn have stopped their free service. I’m not a big user, but it’s handy to get into family PCs so I can sort stuff for them without having to talk them through things.

As I was reaching for my credit card to pay the yearly fee for LogMeIn, I noticed people speaking in the comments about alternative products, so I decided to give TeamViewer a go before parting with my cash.

The result is, it’s fine. If you are a casual user of LogMeIn like me, you might want to consider trying TeamViewer out before parting with your cash.

Note. I don’t have a problem with paying for software, I do it all the time, but if there is a free solution for something I only use on occasion, I’m probably going to go that route.

Cheers

Captain Support…

 

WordPress 3.8.1

WordPress 3.8.1 has been released. You can see the changelog here. Now that WordPress has a true auto-update feature, if you can’t be bothered to manually press the update button today, wait a little while and it will update itself automatically. :)

Happy upgrading (or doing nothing). :)

Cheers

Tim…

Optimisation

Here’s a recent request from the OTN database forum – how do you make this query go faster (tkprof output supplied):