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Oracle Database 12c: Installation and Administration (1Z1-062) beta exam : Free Voucher Competition

I’ve just been sent 5 free vouchers for the Oracle Database 12c: Installation and Administration (1Z1-062) beta exam! Here is an excerpt from the email…

“We are piloting this program with the Oracle Database 12c: Installation and Administration (1Z1-062) beta exam. … we have provided five (5) vouchers for free beta exams. You can use them for a giveaway on your blog if you like. Simply send the voucher number to the winner. They will enter this voucher in the appropriate field during exam registration at Pearson VUE. This beta exam is scheduled to end on October 19, 2013.”

Challenge: Most stupid exhibition freebie you can find at OOW2013

I’ve been challenged by Doug Burns to find the most stupid exhibition freebie as a present for Andy Cowling. I am of course going to cheat as much as possible to win this challenge, so if you see something particularly stupid, can you let me know so I can snag one. Needless to say, keep it a secret from Doug too. :)

If you are an exhibitor and you happen to have a particularly stupid exhibition freebie, feel free to contact me. Once again, make no attempt to contact Doug Burns… :)



PS. Anything really cool, like a free Exadata, might accidentally get kept for myself…


Distributed Sets

In an earlier post I’ve described how a distributed query can operate at a remote site if it’s a simple select but has to operate at the local site if it’s a CTAS (create as select) or insert as select. There’s (at least) one special case where this turns out to be untrue … provided you write the query in the correct fashion. I discovered this only as a result of doing a few experiments in response to a question on the OTN database forum.

Here’s a little demonstration, cut-n-pasted with a little cosmetic editing from an 11gR1 SQL*Plus session:

Warning: Problems with 9.2 clients connecting to databases patched to…

I mentioned this a couple of days ago on Twitter, but I’ve only just go round to posting here…

I recently had to back out some patches because the patch seems to cause problems with Oracle 9.2 client connections where worked fine. I’m not sure how widespread the problem is. All I can tell you is we had two separate occasions (services) where this happened, so we’ve put a halt on patching to until we can identify and upgrade the old clients.

Why are there 9.2 clients lurking around? In some cases it’s due to certification of legacy apps. In other cases it’s because the service owner has been working on a, “if it ain’t broke, don’t fix it”, basis. I guess now it’s broke, we gotta fix it. :)

If you have legacy client installations lurking around, you might want to tread carefully when testing this patch.

Good luck!

Oracle OpenWorld (OOW) 2013 : What am I involved in during the conference?

Oracle OpenWord (OOW) 2013 is just around the corner, so things are starting to heat up… My flights and hotel are booked, so I’ve just got to get myself to the airport at 02:00 next Saturday and I’m laughing, or snoring…

I thought I would just take time out to say a few things about my plans for the conference and make a few apologies in advance.

ACED Briefing

Unfortunately I’m not going to make it to the ACED briefing this year. It will be the first one I’ve missed since I joined the program. There seems to be a bit of confusion about why I’m not going to be there. I’m not getting married. I’m not going to a wedding. My colleague just got married and is on honeymoon, so I’m not allowed to take any time off the week before the conference. It’s a pity, bit this stuff happens. It will definitely not happen next year though!!!

Cloud Control 12c Database Backup Jobs (Continued)

I’ve been rather critical of the way Cloud Control handles database backup jobs, as can be seen in these two previous posts.

Yesterday I found out I schedule database backups in Cloud Control the “wrong way”…

So typically, when I am sorting out a new database, I do something like this:

LAOTN Tour 2003 Interview Videos

During the OTN tour of Latin America, Pablo Ciccarello filmed a number of interviews with the speakers and has recently posted links to them here.

Right at the bottom on the page there is a link to an interview with Dana Singleterry and myself.

If you are interested in listening to our opinions of the tour, drop by and check them out.



System Statistics – “Exadata” Mode

Here’s a very quick note on a relatively recent addition to System Statistics. It’s the so called “Exadata mode”. This mode is intended to give the optimizer a little more info about the storage system on the Exadata platform. Here’s some info from an MOS note.

Oracle Sun Database Machine Setup/Configuration Best Practices [ID 1274318.1]

Verify Exadata specific optimizer statistics have been gathered

Benefit / Impact

Quiz Night

Here’s a little quiz about Bloom filtering. There seem to be at least three different classes of query where Bloom filters can come into play – all involving hash joins: partition elimination, aggregate reduction on non-mergeable aggregate views, and parallelism.

This quiz is about parallel queries – and all you have to do is work out how many Bloom filters were used in the following two execution plans (produced by, and where they were used.

I’ve got 4 tables, 3 very small dimensions and one large fact. I’ve joined the three dimensions to the fact on their primary key, and filtered on each dimension. Stripping out the eighteen hints that I inserted to get the plans I wanted the queries both looked like this:

Advanced Oracle Troubleshooting Guide – Part 11: Complex Wait Chain Signature Analysis with ash_wait_chains.sql

Here’s a treat for the hard-core Oracle performance geeks out there – I’m releasing a cool, but still experimental script for ASH (or poor-man’s ASH)-based wait event analysis, which should add a whole new dimension into ASH based performance analysis. It doesn’t replace any of the existing ASH analysis techniques, but should bring the relationships between Oracle sessions in complex wait chains out to bright daylight much easier than before.

You all are familiar with the AWR/Statspack timed event summary below:

AWR top timed events
Similar breakdown can be gotten by just aggregating ASH samples by the wait event: