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May 2011

A Day of Real World Performance

Tuesday was a fun day this week as Graham Wood, Tom Kyte and Andrew Holdsworth visited London for the latest Real World

Performance Day.

This is an event that has already run several times in the US via the IOUG and consists of a three-person presentation style which I thought worked very well - much better than I expected it to if I'm honest. Each presenter played a different role and often there were slightly different perspectives. Truth be told, I have quite a low boredom threshold sometimes and even with the long presentation slots I didn't find myself drifting off. Multiple top-notch speakers definitely helped.

Regular readers of this blog will be very familiar with most of these chaps. Perhaps less so Andrew Holdsworth who heads up the Real World Performance group at Oracle. If you attend Oracle Openworld you'll be familiar with him but I'm not sure I've ever seen him present in the UK. A lot of the slides would have been familiar to OOW Real World Performance presentation attendees too but, although I might not have learned too much, I preferred the way it was presented here. The day was split up into Data Warehouse-focussed material in the morning and OLTP in the afternoon, which was a useful way of covering a lot of topics whilst highlighting different performance goals.

As most of the people from my current site who attended are predominantly focussed on DW, the morning probably proved more useful. The only slight criticism I might make is that, despite the fact that Andrew was very clear that the first step that everything else was predicated on should be a balanced hardware configuration with enough power, that was easy to forget as the morning went on. So I heard a few people bemoaning the fact that all of the demos were on Exadata and so they wanted to know how much of the stunning improvements were down to Exadata and how much to the approaches used. Personally, I didn't think the absolute numbers mattered so much as the principles illustrated and I thought it was clear that enough power in a balanced configuration was the foundation, whether that's Exadata or (heaven help us!) another platform ;-)

My feeling was that this might not be everyone's Real World Performance on the systems that they're working on which is what perhaps confused people, but was the performance that *should* be possible in the real world if you buy enough kit and use the correct approach. If you've worked on badly configured systems, your own experience might be very different to what's achievable these days. To give you an example, it probably is the case these days that your data loads should be CPU-bound and that compression should be what's limiting your throughput, but that's predicated on not having a useless storage subsystem. I can certainly recall situations where loads were I/O bound so compression was used to speed the loads up and they were *still* I/O bound.

By always keeping in mind 'this is what we should be aiming for', I thought it was all very useful and achievable. Perhaps worth reminding people a little more often that some of the techniques might not deliver if your configuration is wrong but, I repeat, Andrew was very clear that this is the *first* step.

Sadly if you insist that all of your data has to be fed in through Java application servers that pretty much undermines a lot of the morning content, around the Terabyte data loading exercise, but all you can do is try to lead people in the right direction!

One aspect of the Real World Performance presentations I've always appreciated is that they discuss ball-park expectations you should have of different system components and configurations. I know from personal experience of teaching performance courses that many people lack this information and are hungry for it. Fortunately the material is publicly available in a zip file on Tom's site so I don't

need to cover the technical details.

(Note, however, that this is just the slide material and doesn't cover the demos, the questions and answers and dialogue so it's a poor substitute for the experience of attending.)

There's much more I could say about the day. I know a couple of colleagues who enjoyed it as much as I did and found it useful (some more than others) to the extent that I think they might be attending a few more conferences in future if they're this good

Congratulations to all involved and I'll finish with a piece of good news for those who missed it. According to Thomas Presslie (@tpresslie) there will be another run of the same event in Edinburgh on the 23rd August 2011. Not to be missed!

XFILES APEX Community Edition (XACE)

Roel Hartman and me are currently very busy with our Kaleidoscope 2011 presentation “XFiles, the APEX Version: The Truth is in There…“. During this presentation, we will demonstrate the awesome possibilities you can create when you combine the APEX and XMLDB functionality of the APEX database environment. And as you probably also know, two “no cost options” delivered with your Oracle database. Our first presentation/demo will be on the AMIS Kaleidoscope Preview Sessions on the 14th of June, to test our “setup” and combined presentation for the real thing during Kaleidoscope, in Long Beach, USA, this year.

Background

The demo will demonstrate how to setup database build-in versioning capabilities, based on standard XMLDB functionality, that can be used by or for APEX applications, while making use of the file/folder metaphor of the XDB Repository.

XFILES APEX Community EditionClick picture to enlarge

The XDB Repository can, by default, be used to, currently via WebDAV or FTP, drag and drop files into the database. This XMLDB functionality also has default versioning, checkin/out, an repository event mechanism and security functionality / capabilities. So why work, while working with this great development environment called APEX, with version tooling like Subversion, if the XMLDB realm of the database already has these capabilities to provide this by default.

The XFILES demo application is used to demonstrate XMLDB functionality but currently still main AJAX based regarding its GUI. In 2008 an effort was made, for that years Oracle Open World conference, by Carl Backstrom (Oracle APEX) and Mark Drake (Oracle XMLDB) to combine the two environments and switch the XFILES AJAX based GUI for the APEX front-end. Due to circumstances, it didn’t had the proper follow up regarding cleaning up the code and share the ideas…see the XFILES tab on this page for more info on this.

Roel and my efforts, regarding this XFILES APEX version, which is based on current and the work done by Mark en Carl in 2008, is called by us, the XFILES APEX Community Edition (abbreviated to XACE), so we are able to implement some chance management without be mistaken by Mark Drake’s still existing AJAX based XFILES version, currently version 5. This version implements and demonstrates Native Database Web Services via XMLDB in the OTN Development Days Virtualbox environment which can be downloaded via Oracle OTN.

More info needed?

More regarding the XFILES XMLDB application and blog posts can be found via the XFILES menu on this site. Information about Roel and his interests can be found on his personal blog roelhartman.blogspot.com and information about official XFILES Oracle XMLDB application and technology can be found on and via the Oracle XMLDB main page. Last but not least, for interest in Oracle APEX go to the apex.oracle.com site.

Preview

To give you a preview of the work done, hereby some updated pictures

XACE - Home PageClick picture to enlarge
XACE - Browser MenuClick picture to enlarge

Missing information in SQL*Plus

By preference I like to work against the databse using SQL*Plus. GUIs are fine and they are much better for developing code than using sql*plus and notepad (or vi or whatever ascii text editor floats your boat). However, for finding things out quickly and also storing what I find (via spool files) then sql*plus is much better. As screens have got larger, I have used a larger – and wider – sql*plus session to show more information at one time.
But I have been having an issue with SQL*Plus not showing some information. I lose information on the right hand side of the screen.

This is on the V10 client on Windows by the way, I’ve seen it on windows XP to Vista.

Look at the below. It is quite a wide output and I have had to increase the standard 80 character linesize from 80 up to 120:

{BTW if you are looking at this in a small browser winder, you might have to click on the screen shot to open it up in it’s own window, to see what I mean – it is quite wide, that is the point of the post – it should just fit in my over-wide blog layout :-) }

set linesize 120

AUDIT_PROGRAM            entry_dt ENTRY_TS     AUDIT_TEXT                                                    aud_val1   aud_val2
------------------------ -------- ------------ -----------------------------------------------------
MM_STATS_GATHER          19-05-11 04.46.39.599 Index EVE_CAT_USER_FK_I Partition EVE_I_TOP                          0        100
MM_STATS_GATHER          19-05-11 04.46.39.571 Index EVE_IDX Partition EVE_I_TOP                                    0        100
MM_STATS_GATHER          19-05-11 04.46.39.556 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_TOP                        0        1
MM_STATS_GATHER          19-05-11 04.46.39.519 Index EVE_CAT_BANK_FK_I Partition EVE_I_TOP                          0        100
MM_STATS_GATHER          19-05-11 04.46.38.846 Table EVENTS Partition EVE_D_TOP                                     0        100
MM_STATS_GATHER          19-05-11 04.46.32.497 Index EVE_CAT_USER_FK_I Partition EVE_I_2011_07                  4,962
MM_STATS_GATHER          19-05-11 04.46.20.787 Index EVE_IDX Partition EVE_I_2011_07                          437,500
MM_STATS_GATHER          19-05-11 04.46.09.939 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_2011_07               91,
MM_STATS_GATHER          19-05-11 04.45.58.613 Index EVE_CAT_BANK_FK_I Partition EVE_I_2011_07                441,2
MM_STATS_GATHER          19-05-11 04.45.44.534 Table EVENTS Partition EVE_D_2011_07                           927,950
MM_STATS_GATHER          19-05-11 04.45.41.207 Index EVE_CAT_USER_FK_I Partition EVE_I_2011_04                  6,324
MM_STATS_GATHER          19-05-11 04.45.22.638 Index EVE_IDX Partition EVE_I_2011_04                          771,840
MM_STATS_GATHER          19-05-11 04.45.17.024 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_2011_04              168,
MM_STATS_GATHER          19-05-11 04.45.05.463 Index EVE_CAT_BANK_FK_I Partition EVE_I_2011_04                848,0
MM_STATS_GATHER          19-05-11 04.44.55.474 Table EVENTS Partition EVE_D_2011_04                         1,625,100
MM_STATS_GATHER          19-05-11 04.44.47.100 Index EVE_CAT_USER_FK_I Partition EVE_I_2011_01                    461
MM_STATS_GATHER          19-05-11 04.44.23.829 Index EVE_IDX Partition EVE_I_2011_01                          800,020
MM_STATS_GATHER          19-05-11 04.44.03.673 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_2011_01              158,

Note that for line 8 onwards there is no value for aud_val2. But then, some of the numbers in aud_val1 also look odd. But I’m getting output for some of the lines…

I am in fact getting some of the lines truncated. It just seems to be a bug in the V10 sql*plus client and it might pass you by as the first few lines usually come out “full length”. This truncation only happens if you increase the linesize.

To fix it, you need tell the “windows” sql*plus window how big your output now is. Click on the options and then environment menu items at the top left of the screen:


Change the SQL*Plus environment

Now set the screen buffer width to a bit more than it was, say by one character (and whilst you are at it, why not increasre the buffer length to 2000, the memory required is peanuts on today’s machines). I actually tend to set it to 140 to anticipate some of my more verbose scripts.


Alter the screen buffer width to one or two characters more

And confirm that you are happy to “truncate the buffer” – whoever coded this did not bother to check if you alter the values up or down – you can ignore this message if you are simply increasing the buffers.


Accept the prompt about truncation

Now when I run my sql statement I see the full output {Again, click on the image to see it’s full length to fully see how the problem is now fixed}:

AUDIT_PROGRAM            entry_dt ENTRY_TS     AUDIT_TEXT                                                    aud_val1   aud_val2
------------------------ -------- ------------ ------------------------------------------------------- -------------- ----------
MM_STATS_GATHER          19-05-11 04.46.39.599 Index EVE_CAT_USER_FK_I Partition EVE_I_TOP                          0        100
MM_STATS_GATHER          19-05-11 04.46.39.571 Index EVE_IDX Partition EVE_I_TOP                                    0        100
MM_STATS_GATHER          19-05-11 04.46.39.556 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_TOP                        0        100
MM_STATS_GATHER          19-05-11 04.46.39.519 Index EVE_CAT_BANK_FK_I Partition EVE_I_TOP                          0        100
MM_STATS_GATHER          19-05-11 04.46.38.846 Table EVENTS Partition EVE_D_TOP                                     0        100
MM_STATS_GATHER          19-05-11 04.46.32.497 Index EVE_CAT_USER_FK_I Partition EVE_I_2011_07                  4,962        100
MM_STATS_GATHER          19-05-11 04.46.20.787 Index EVE_IDX Partition EVE_I_2011_07                          437,500          5
MM_STATS_GATHER          19-05-11 04.46.09.939 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_2011_07               91,395         20
MM_STATS_GATHER          19-05-11 04.45.58.613 Index EVE_CAT_BANK_FK_I Partition EVE_I_2011_07                441,240          5
MM_STATS_GATHER          19-05-11 04.45.44.534 Table EVENTS Partition EVE_D_2011_07                           927,950          2
MM_STATS_GATHER          19-05-11 04.45.41.207 Index EVE_CAT_USER_FK_I Partition EVE_I_2011_04                  6,324        100
MM_STATS_GATHER          19-05-11 04.45.22.638 Index EVE_IDX Partition EVE_I_2011_04                          771,840          5
MM_STATS_GATHER          19-05-11 04.45.17.024 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_2011_04              168,840          5
MM_STATS_GATHER          19-05-11 04.45.05.463 Index EVE_CAT_BANK_FK_I Partition EVE_I_2011_04                848,060          5
MM_STATS_GATHER          19-05-11 04.44.55.474 Table EVENTS Partition EVE_D_2011_04                         1,625,100          1
MM_STATS_GATHER          19-05-11 04.44.47.100 Index EVE_CAT_USER_FK_I Partition EVE_I_2011_01                    461        100
MM_STATS_GATHER          19-05-11 04.44.23.829 Index EVE_IDX Partition EVE_I_2011_01                          800,020          5
MM_STATS_GATHER          19-05-11 04.44.03.673 Index EVE_AGR_CNTRPY_FK_I Partition EVE_I_2011_01              158,600          5

Flip is dead, Long live Flip…

I needed to update my Flipshare software and get some of the movies made from my Flip when I noticed that current owner Cisco will close down its Flip business and support current FlipShare customers and partners. Probably it was never a good idea of Cisco to go in “the movie” business anyway… It’s a shame for the Flip though it will stop “to exist” as is on 31/12/2013 when also support will close down.

For gadget hunters this could be a time to make a final move to get the last stock, as is mentioned on this Cisco/Flip link:

Cisco closes its Flip Video Business to focus on extending network-centric platforms and services to create a connected experience from businesses to home. Cisco will no longer be manufacturing any new Flip video cameras for this product line.

However, Cisco is currently working with its partners to offer existing stocks of third generation Flip video cameras at an affordable price.

All new Flip video cameras will still come with the same manufacturer’s warranty. Cisco will maintain the necessary support mechanisms to provide world-class customer service within the warranty period.

Cisco will also continue to provide technical support for both Flip video cameras and FlipShare until December 31, 2013. To learn more about the future of Flip, click here

So in short, my conclusion: “Flip is dead, Long live Flip”.

It had a remarkable impact on the market regarding design and simplicity, something this “camera” really excels in. That simplicity is not that easy to achieve while still doing some remarkable smart things within the product, can only be admired by, I guess, all that try to achieve this in one way or another. The Flip, as a concept, has already been copied by many manufactures…

FlipAMIS-2
FlipAMIS-1
FlipAMIS-3

Click on a picture to enlarge

The Flip was a robust and easy to use movie camera, which also could be used by my mother or daughter. Every one got the simplicity of “push the red button to make a movie and push it again to stop. Voila! Your first HD movie… I use it still during conferences because its small, robust and actually all I need to tape something…

It think it is a shame that Flip closes down.

Regarding functionality, simplicity and smartness it could rival with an Apple designed gadget…

Clustering_Factor

Being a very reserved British type of character I’m not really one to make a big fuss about advertising myself, which is why it’s taken me five years to realise that I ought to make it easy for people to find the free download of Chapter 5 (Clustering Factor) of Cost Based Oracle Fundamentals.

Apress changes the relevant URL from time to time, and I’ve just discovered that they’ve now bundled the pdf file of the chapter into this  zip file.

The thing that prompted me to post this special note was that some time ago Mohamed Houri translated the chapter into French as a gesture of appreciation for the fact that I had written the book and Apress has given me permission to post the translation, which is this pdf file.

While I’m on the topic of French translations I’ll just add a temporary note to point people to the listing of articles translated into French by Franck Pachot, where I’ve just added seven new items, five of mine and two from Greg Rahn.

HOWTO: Reset the admin password for the stand-alone APEX Listener

Sometimes the answer can be so simple…

I wanted to reset the OTN Developer Days Virtualbox APEX Listener admin password without redeploying the apex.war file and destroying the current setup, so I searched all config and properties APEX Listener files I could find. Searched via Google. No useful hits. I found a credential file with the passwords in them on the virtualbox environment, probably MD5 hashed ones, but no clue about how to reset them. At final I got in direct contact with Kris Rice which had put so much effort in setting up this training environment…and was a bit startled about the simple solution…

Marco,
There’s a file named credentials under ~/.apex/[port numner]/. If you remove that, it will reprompt for the passwords. Let me know if you need anything else.

-kris

Life can be so simple.

Oracle VM [not] running inside VirtualBox… (update)

I mentioned a few days ago I was having trouble running Oracle VM inside VirtualBox. I had tried with multiple versions of VirtualBox (including the latest 4.0.8), so I finally decided that is must be an issue with the host OS (Fedora 14).

Today I worked up the enthusiasm and trashed my server by replacing the host OS with CentOS 5.6. Regarding Oracle VM and VirtualBox, the news is good. I now have a functioning OVM installation inside a VirtualBox VM, so I can get back to playing with OVM again.

I don’t know exactly what the problem was, but for the moment I’m going to bury my head in the sand and think happy thoughts. I’ve wasted far to much time with this already. :)

Cheers

Tim…




VirtualBox 4.0.8 Released…

VirtualBox 4.0.8 has been released. Happy upgrading… :)

Cheers

Tim…




I don’t use GUI. Manly Men use SQL

GUI gets a bad rep because a lot of neophytes can get away with half managing systems via graphics. A lot of graphics are completely useless, distracting or worse misleading. On the other hand I have to smile when I hear this phrase “we don’t use GUI”.

It’s like badge of honor. Maybe that’s just the way I hear it. Maybe some of my friends really mean, “graphics are great, but the tools that exist are bad”. Then again, I know how to ruffle the feathers at a conference when I give a talk on graphics. If I’m talking about graphics all I have to say is “I bet there is no one out there in the crowd who would refuse to use a good graphic tool”. Typically half the crowd will shuffle in their seats a bit when I say this. I know what they are thinking … “I ONLY use SQL*Plus”.

It’s clear that graphic data is more powerful than textual data.
That’s not the question. The question, the issue, is access to efficient fast programs that display data graphically in an intelligent manner and  that allow easily asking new questions of the data and drilling into the data with new graphical representations. Oracle’s OEM performance page and top activity pages were a step in the right direction, but had limited drilldown (and slow) and no way to rephrase the questions a user might have.  A good example of a tool that shows data powerfully and graphically and allows rephrasing of questions and outputs answers in  new graphical presentations  is Sun’s (now Oracle’s) Fishworks.  Additionally there are things that I can’t see in text that I can see in graphics, for example check out these.

There is a time for text and a time for graphics. Graphics lead the way to the text that is worth spending time analyzing.

I just finished reading “Brain Rules” today and like these tidbits on Text verses Graphics:

p233-234

“pictures demolish ” text and oral presentations

“the inefficiency of text has received particular attention” … “reading creates a bottleneck” … “to our cortex, unnervingly there is no such thing as words”

“tests performed showed that people could remember more than 2500 pictures with at least 90% accuracy several days post-exposure, even though the subjects saw each picture for about 10 seconds. Accuracy rates a year later  still hovered around 63 percent. ”

“words are only the postage stamps delivering the object for you to unwrap” – George Bernard Shaw

Or as Einstein said it:

“If I can’t picture it, I can’t understand it”


by the way we do not use blogs either, checkout : http://www.wedonotuse.com/

(thanks to Wolfgang Breitling for the reference)


Large Page Support or Not – ORA_LPENABLE, Granule Size

May 17, 2011 Have you ever tried to bounce a database (maybe to adjust a parameter such as PROCESSES, which can only be altered in the spfile/init.ora) and encountered something like this (note that this is on a 64 bit Windows server): SQL> shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down. SQL> startup [...]