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Google Android in an Integrated Communication Device As a Home / Kitchen Unit

Khanderao Kand - Thu, 2009-11-12 22:57
My blog on this ...

http://texploration.wordpress.com/2009/11/13/google-android-in-action-in-home-device-by-vega-icd/

Data Modeling

Jared Still - Thu, 2009-11-12 13:24

Most readers of the blog are probably DBA's, or do DBA work along with development or other duties.

Though my title is DBA, Data Modeling is something I really like to do.

When first learning Oracle, I cut my teeth on data modeling, and used CASE 5.1 on unix to model a database system. True, CASE 5.0 used an Oracle Forms 3.x based interface, and the GUI modeling was unix only.

That was alright with me, as the Form interface allowed manual changes to be made quite quickly.

And the graphic modeling tool was fairly decent, even on a PC running Hummingbird X Server.

When Designer 2000 came out, it was clearly a more capable tool. Not only did it do everything that CASE 5.1 could do, it could do more. I won't make any silly claim that I was ever able to fully exploit D2K, as it was an end-to-end tool that could do much more than model data and databases.

What it could do with just the databases however was quite good.  Data models could be created, and then a physical database could be generated from the model.

Changes in the database model could be reverse engineered back to the model, and changes in the model could be forward engineered in to the physical model. D2K could truly separate logical and physical models, and allow changes to be migrated back and forth between the two.

There are other high end tools such as Erwin which can no doubt accomplish the same thing, but I have not used them.  

One important differentiation for me between D2K and other tools was that D2K worked with Barker Notation, which is the notation I first learned, and the one I still prefer.  

I should not speak of Designer 2000 in past tense I guess, as it is still available from Oracle as part of the Oracle Development Suite, but is now called Oracle Designer.  It just hasn't received much attention in the past few years, as I think many people have come to think of data modeling as too much overhead.  

I've tried several low end tools in the past few years, and while some claim to separate logical and physical models, those that I have tried actually do a rather poor job of it.

All this leads to some new (at least, new to me) developments from of all places, Microsoft.

Maybe you have heard of Oslo, Microsoft's Data Modeling toolset that has been in development for the past couple years.

If you're just now hearing about it, you will likely be hearing much more. The bit I have read has made me think this will be a very impressive tool.

If you have done data modeling, you have likely used traditional tools that allow you to define entities, drop them on a graphical model, and define relationships.

The tool you used may even have allowed you to create domains that could be used to provide data consistency among the entities.

Oslo is different.  

Oslo incorporates a data definition language M. The definitions can be translated to T-SQL, which in turn can be used to create the physical aspects of the model.  M also allows easy creation of strongly typed data types which are carried over into the model.

Whether Oslo will allow round trip engineering ala D2K, I don't yet know.

I do however think this is a very innovative approach to modeling data. 

Here are a few Oslo related links to peruse :


You may be thinking that I have given SQL Developer Data Modeler short shrift.

Along with a lot of other folks, I eagerly anticipated the arrival of SQL Developer Data Modeler.

And along with many others, was disappointed to learn that this add on to SQL Developer would set us back a cool $3000 US per seat.  That seems a pretty steep price for tool that is nowhere near as capable as Oracle Designer, which is included as part of the Oracle Internet Developer Suite. True the price is nearly double that of SQL Modeler at $5800, but you get quite a bit more than just Designer with the Suite.

As for the cost of Oslo, it's probably too early to tell.

Some reading suggests that it will be included as part of SQL Server 2008, but it's probably too soon to tell.

Why all the talk about a SQL Server specific tool?

Because data modeling has been in a rut for quite some time, and Microsoft seems to have broken out of that rut.  It's time for Oracle to take notice and provide better tools for modeling, rather than upholding the status quo.







Categories: DBA Blogs

Googlers announced "Go" Programming language

Khanderao Kand - Wed, 2009-11-11 17:24
googlers announced a new programming language "Go" w






Go is being advertised as Fast (to compile), Safe(pointers without pointer maths), Concurrent (lightweight process communication) and Cool (dynamic language but has the speed and safety of a static language) and open source...   disclaimer: I am yet to validate these claims...

Here is a video clip introducing the Go

http://www.youtube.com/watch?v=wwoWei-GAPo

Googlers:
Robert Griesemer
Kenneth Thompson
Rob Pike
Russ Cox
Ian Lance Taylor

Quite frankly warticki, you should apologize!

Nuno Souto - Wed, 2009-11-11 03:33
(edited to remove stronger words, no need for that and I apologize to my readers)Here we go. I already expected this...A perfect example of the low-life, unprofessional, kind of people that populate Oracle Support nowadays.chris - if that is indeed your name: 1- With the exception of a lonely voice, there has not been ONE SINGLE POSITIVE user community comment about the utter disaster that was Noonsnoreply@blogger.com10

Strange cloud heads for Iceland

Peter O'Brien - Tue, 2009-11-10 10:02

Google appears to be always thinking about new tools or approaches to make or save money. Lots of these ideas sneak out onto the internet and lots of discussions, articles and opinions get generated. Occasionally, a real product is eventually seen. Way back in 2008 rumours about a Google data centre navy abounded. That particular Times Online article mentions some statistics and reports about data centres and carbon footprint which I have yet to verify. However, other articles and press releases have suggested the data is not without foundation. Here's a quote:
Data centres consumed 1 per cent of the world’s electricity in 2005. By 2020 the carbon footprint of the computers that run the internet will be larger than that of air travel, a recent study by McKinsey, a consultancy firm, and the Uptime Institute, a think tank, predicted.
It was with great interest that I read about a zero carbon foot print data centre being proposed in Iceland. The data centre will not be up and running until next year, but is being built on an old NATO base. Expecting to take advantage of free ambient cooling and 100% renewable electricity verneglobal are predicting substantial reductions in carbon released from day to day operations.

While a great idea, I feel the greatest speed bump in the migration to Iceland is regulation and legislation, or rather the perception of compliance with data privacy laws and in particular the Patriot Act.

MetaLink, we barely knew ye

Jared Still - Mon, 2009-11-09 14:08
But, we wish we had more time to get better acquainted.

If you work with Oracle, you probably know that MetaLink went the way of the Dodo as part of an upgrade to My Oracle Support during the weekend of November 6th, 2009.

And so far it hasn't gone too well, as evidenced by these threads on Oracle-L:

Issues with My Oracle Support
Metalink Fiasco

Many people were lamenting the loss of MetaLink well before its demise, but I don't think any were quite expecting the issues that are currently appearing.

A few have reported that it is working fine for them, but personally, I have found  it unusable all morning.

At least one issue with MetaLink appears to have been cleared up with MOS, that is while I was able to login to it last week.

During a routine audit of who had access to our CSI numbers, I came across a group of consultants that were no longer working for our company, and froze their accounts.  The next day I received a frantic voice mail  from a member of the consulting firm, and he informed me that they had no access to MetaLink because I had frozen their accounts.


I returned the call just a few minutes later, but they had already been able to resolve the issue, as one of their consultants with admin rights had been unaffected, and was able to unfreeze their accounts.


Removing them from the CSI is the better procedure, but in the past when I have attempted to do so, I found that there were still open issues owned by the accounts, and could not remove them. The application owners had been very clear that this access should be removed, so I froze the accounts, so that is what I did on this occasion as well.


This all seemed quite bizarre to me.  This must be a very strange schema in the ML user database, and some strange logic to go along with it.  By granting a user access to a CSI, MetaLink was giving me Carte Blanche to effectively remove them from MetaLink.

How has My Oracle Support fixed this?  Try as I might, I could not find a 'freeze' button in user administration in MOS.  So the fix seems to have been "remove the button"

Categories: DBA Blogs

Ireland's new Baywatch mashup

Peter O'Brien - Wed, 2009-11-04 06:57
Due to a new initiative from the EPA you can keep up to-date on the water quality of Ireland's major bays (hence the article title), beaches and rivers. Made possible by some hard work from the clever people at IBM's Water Management Centre of Excellence, Splash provides a great way to research different beaches and decide where to visit based on a number of parameters — water quality, weather, and whether or not a lifeguard is on duty, and so on. You'll note from the spelling of Centre that it is European based. In fact it's current home is right here in Dublin.

The site is a clever mashup of EPA water quality data, which is provided by the local councils, some location data and weather reports from AccuWeather. There also appears to be a Twitter status check as well but I have not seen any data from this actually displayed on the site. The location data includes a description of the area and some images.

For the Oracle offices in Dublin, the nearest beach is Dollymount Strand. The Splash website provides the following description:
Dollymount provides tremendous respite from Dubliners from the vagaries of city living. It is along beach with sweeping views of the Dublin Mountains. This seaside area and wildlife reserve is located north of Dublin Harbour. The strand is connected to the shore by a late 19th century wooden bridge. Dollymount is on the seaward side of Bull Island, one of the most protected pieces of property in Ireland. Cars are allowed on a small section of this beach which is separated from the Blue Flag beach by wooden pilings.
I'm not sure how 'respite from Dubliners' is achieved. Anytime I've been on the beach, at least one Dubliner has been there. The images are also of great interest as the site provides a birds eye view that you can zoom in and out of as well as a photo of the location. No Dubliners, or people for that matter appear in the images, so perhaps that is the respite referred to.
One of the IBM blogs suggests that this form of mashup will be rolled out to other countries in the future. Personally, I think this is a great example of innovation within Ireland and I look forward to seeing more if it.

Bye Bye Metalink, Hello MOS - My Oracle Support. Fingers crossed for continued HTML content!

Gareth Roberts - Tue, 2009-11-03 20:26

Disclaimer: This page may become out of date very quickly!

Only a couple of days of Metalink access left, with the change over to full My Oracle Support due on Friday - 6 November 09.

For me this is a somewhat sad occasion. Metalink has been around for such a long time, and has been a great companion, it will be a shame to see it go.

We now herald in the era of MOS (My Oracle Support). And of course, with any shiny new thing, there have been discussions and more discussions. With that debate there has been some good feedback, some negative. To be honest I'm a bit nervous about this change. I'd be keen to know why the APEX interface of Metalink is on the out, when APEX was just brought in for the latest Oracle Store, and with some very sexy functionality on the horizon. The answer is sure to be a double edged sword ;-)

At the end of the day MOS as I've seen so far just doesn't tick all the boxes for me. That will hopefully change. Hopefully soon. My biggest gripe of course would be Flash versus HTML. Given Oracle's current catchphrase "Open. Complete. Integrated." I'd have thought Flash would be a little further down the list than HTML for many of the MOS components. One issue related to this can be summed up by the following screenshot. The eagle-eyed amongst you will spot the problem in the following picture:

… with the issue being the Firefox "Find" not finding "Font" when it was present many times on the MOS search results presented. A bit of a hassle that something I use regularly ain't gonna work. Guess I'll need to have two sessions up, one Flash, one HTML.

Fortunately, it seems an HTML interface will still be available according to Note 841061.1, with limited functionality including SR Management? BUT WAIT ... while I was writing this post I got another MOS related announcement... No SR Management??? Hmm, this is specific to "On Demand" functionality. Fingers crossed for SR Management through the HTML only interface!

The HTML option will not support the following On Demand functionality:

  • Service Request management
  • Change Request Management
  • Viewing performance reports

And there are some other little things that will probably come out in the wash, like email notifications no longer linking directly to an SR:

Prior:

New:

Oh, and of course, let's hope the powers that be manage to keep the gremlins away...

Exception Gremlin:

I/O Gremlin:

Error 1088 Gremlin:

Internal Gremlin:

Well ... I guess we'll find out where we stand in a couple of days!

Catch ya!
Gareth
This is a post from Gareth's blog at http://garethroberts.blogspot.com
References Related Posts

Pay it forward…

Lisa Dobson - Tue, 2009-11-03 10:47
A couple of things recently, both personally and professionally, have reminded me of the concept of ‘Pay it Forward’. When somebody does you a favour, you repay it by helping out someone else. It was this concept that got me started with planning my first ever UKOUG presentation, which led to the blog. I’d had a great deal of help and encouragement from people within the community and I wanted Lisahttp://www.blogger.com/profile/16434297444320005874noreply@blogger.com5

Good Article About btrfs

Sergio's Blog - Tue, 2009-11-03 06:56

I found this article about btrfs helpful.

Categories: DBA Blogs

Landmark achievement for my team - Cisco announced as overall winner for SOA implementation award by CIO magazine and SOA Consortium.

Arvind Jain - Mon, 2009-11-02 20:13
Landmark achievement for my team - Cisco announced as overall winner for SOA implementation award by CIO magazine and SOA Consortium.




Cisco SOA Team Wins SOA Consortium / CIO Magazine Award


Cisco has been selected as the overall winner of the 2009 CIO Magazine “SOA Case Study Competition“ organized by the SOA Consortium. Please see detailed news article here.

Cisco was recognized by industry experts for its SOA initiatives, platform and implementation successes.
The SOA Case Study Competition highlights business success stories and lessons learned to provide proof points and insights for other organizations considering or pursuing SOA adoption. The contest was open to organizations of all sizes, including government agencies that have successfully delivered business or mission value using an SOA approach.
CIO Magazine, launched in 1987, produces award-winning content and community resources for information technology executives. The SOA Consortium is a group of renowned industry experts and practitioners, who through the years honor companies for outstanding achievement with this award.

If you are interested in the case study then please contact me offline at arjain@cisco.com

Two Oracle RAC bugs on the wall, two Oracle bugs. Take one down …

Freek D’Hooge - Mon, 2009-11-02 18:50

Ok, not as good as beer and they can give you a nasty headache, so you have been warned   ;)

Reason for this post are 2 bugs I discovered with Oracle RAC, both resulting in a single point of failure.
The platform on which I’m working is Oracle 10gR2 (10.2.0.4) on OEL 4.7.

The first one is when you are using NFS volumes to host the ocr and ocrmirror volumes.
Normally, when the ocr volume gets corrupted or unavailable , oracle should failover to the ocrmirror volume. The exact response is documented in the RAC FAQ on metalink (note 220970.1) and is currently discussed in a series of blog posts by Geert de Paep.
With NFS, however, you must use both the nointr and hard mount options (OS is OEL 4.7) and as a result the process that is trying to read or write an unavailable ocr volume will wait undefinitly on a response. This is not only happening when using commands such as crs_stat or srvctl, but also when an instance or service failover is initiated.
Oracle support however, does not exactly see it this way and has first blamed the os, then the storage and finally stated that there is no failover foreseen between the ocr and ocrmirror volumes…
It took some escalating and a change in support engineer to get some progress in that SR (mind you that after more then 4 months, they still have not acknowledged it as a bug).

The second problem is that, when you made the public interface redundant with os bonding, the racgvip script does not detect when all interfaces in the bond are disconnected.
This is caused because the script, unlike older version, is using mii-tool to check the availability of the public interface. Only when mii-tool states that the link is down, a ping test is done to the public gateway. If that test fails as well, then the vip fails over and the rac instances on that node are placed in a blocked state.
The problem however with mii-tool is that it plays not very well with bonds, and always reports the bond status as being up (in fact, regardless of the link state, mii-tool is always reporting a network bond as “bond0: 10 Mbit, half duplex, link ok”). So, the racgvip script always thinks that the public interface is up.
As mii-tool is an os utility, I first opened a case on the Oracle Enterprise Linux support, to check with them if its behavior was normal (I already confirmed that by googeling, but Oracle support does not seem to accept results from google :)   ). And after running multiple tests with different bond options, they finally stated that mii-tool was indeed obsolete and should not be used to verify a bond status (yes, I know. Its own man page already states that mii-tool is obsolete).
So next, I opened a SR on part of the clusterware and oracle development promptly stated that it was not a clusterware bug but an os issue, pointing the finger to mii-tool and asking where it was written that mii-tool is obsolete… . After making them aware of the statement made by their OEL colleagues and the mii-tool man page, they have seemed to have accepted it as a bug.
I have checked the 11gR2 version of the racgvip script, and it seems to suffer the same problem.

ps) Note 365605.1 – “Oracle Bug Status Codes, Descriptions and Usage” is, although it seems incomplete, very usefull to understand the different status codes


Categories: DBA Blogs

Now where are those user accounts?

Oracle WTF - Sat, 2009-10-31 10:21

The IM conversation below is part of a much longer one (notice the date stamps) between a friend who we'll just call 'TR' and a developer.

Developer (11 Oct 2009 14:39:51): I created some users and now they are gone?
TR (11 Oct 2009 14:40:01): We have implemented a daily flashback to the data baseline so that repeatable tests can run every day in that database.
TR (11 Oct 2009 14:40:03): You need to notify us (as per the mail I sent out) when you make data changes that you want to keep from day to day.
TR (11 Oct 2009 14:40:06): Ok, so could you please create those users again and let me know? I'll create a new baseline for the refresh....
Developer (11 Oct 2009 14:45:51): i wonder if i ll be able this afternoon
Developer (11 Oct 2009 14:46:12): so i can do it tomorrow and send you the list
Developer (11 Oct 2009 14:46:25): You can go ahead wit the refreh of today without my users
TR (11 Oct 2009 14:48:29): Ok, I don't need the list, just to know once you have created them.
Developer (11 Oct 2009 14:50:18): ok

Developer (20 Oct 2009 16:57:53): hi TR
TR (20 Oct 2009 16:57:59): Hi
Developer (20 Oct 2009 16:58:06): Are you still doing the DB refresh on daily basis?
TR (20 Oct 2009 16:58:20): Yes. It's automatic, I don't actually *do* anything.
Developer (20 Oct 2009 16:58:24):
Developer (20 Oct 2009 16:58:27): ok
Developer (20 Oct 2009 16:58:33): then
Developer (20 Oct 2009 16:59:22): i see
Developer (20 Oct 2009 17:01:42): actually i m looking for this user on alpha qa2_PN3D8J20aa
Developer (20 Oct 2009 17:01:52): i can't find it in the db
Developer (20 Oct 2009 17:02:04): and when i m logged in with it, I added it yesterday and now it's gone
Developer (20 Oct 2009 17:03:02): i ll try using other users
TR (20 Oct 2009 17:16:21): You didn't tell me that you had created these users. The database is refreshed every night back to the baseline...as we discussed
TR (20 Oct 2009 17:16:21): If you add data you have to let me know and I will create a new baseline.

TR (21 Oct 2009 16:08:49): These users that you need. Are they in the database now?
Developer (21 Oct 2009 16:09:02): not yet
Developer (21 Oct 2009 16:09:07): but i can ping them to you
Developer (21 Oct 2009 16:09:12): at least the login
TR (21 Oct 2009 16:09:19): You don't need to ping them to me. Just tell me when they're created
Developer (21 Oct 2009 16:09:25): ok
Developer (21 Oct 2009 16:09:52): but got too much to do today probably will have them ready monday morning
TR (21 Oct 2009 16:10:20): Ok, so as per last time....when they are created please let me know.
Developer (21 Oct 2009 16:10:30): ok

Developer (25 Oct 2009 13:18:21): hi TR
TR (25 Oct 2009 13:18:27): Hi
Developer (25 Oct 2009 13:18:31): what's time is the DB refresh taking time ?
TR (25 Oct 2009 13:18:41): 00:00GMT
Developer (25 Oct 2009 13:18:44): ok
Developer (25 Oct 2009 13:18:52): i ll ping you by the end of the day my new users
TR (25 Oct 2009 13:18:57): Ok, you don't need to ping me the users, just create them and tell me when you have done it
Developer (25 Oct 2009 13:19:01): in the mean time
Developer (25 Oct 2009 13:19:25): I'm working on a script to insert our users in the Db before each time
TR (25 Oct 2009 13:19:39): Ok, you don't need to do that, just create them and tell me when you've done it.
Developer (25 Oct 2009 13:19:48): so this will help us lot and you will be free to do your updates as you want and delete our users if you need to
TR (25 Oct 2009 13:20:02): Ok great. But the process is already working, you just have to tell me once you've created them and they will always be there
Developer (25 Oct 2009 15:00:26): hi TR
Developer (25 Oct 2009 15:00:34): what do i have to give you about the created users? only login
TR (25 Oct 2009 15:00:43): nothing, just tell me when you've create them.
Developer (25 Oct 2009 15:00:48): or Zid, Xid...
Developer (25 Oct 2009 15:00:54):
TR (25 Oct 2009 15:00:54): just tell me WHEN they are created...so I can add them to the baseline.
Developer (25 Oct 2009 15:01:04): today
TR (25 Oct 2009 15:01:17): they are there now?
Developer (25 Oct 2009 15:01:21): not yet, but I will create these users
Developer (25 Oct 2009 15:02:07): ppm_alpha_4 ppm_alpha_5
Developer (25 Oct 2009 15:02:21): ppm_alpha_2 ppm_alpha_3 ppm_alpha_4 ppm_alpha_5
Developer (25 Oct 2009 15:02:21): please don't delete them this time

Change OWB location details

Klein Denkraam - Fri, 2009-10-30 07:33

If you have used your locations to deploy objects to them (who doesn’t?), you cannot change the connection details easily. In the Design Center they are greyed out. The only way you can change them is by starting the control center, unregistering the location, reregister with the new details and deploy all objects again to regain the right deployment status. The last is something you cannot always do because that would mean e.g. dropping tables that already contain data you do not want to lose. Not an ideal situation.
Today I was reading this post about upgrading to 11gR2 which was a good post. Although I’m currently upgrading to OWB 11gR1 as 11gR2 is not yet available on Windows. Stewart Bryson had some trouble because during the upgrade his connection details where automagically updated. He first described how to change the connection details in the ‘old-fashioned’ way I just mentioned. But more importantly he described a second possibility I did not know of. It is possible to change the details using the OWB Repository browser! I do not start the Repository browser very often because it tends to slow down once you have had your share of deploying and executing. A simple view suffices most of the time (I’ll reserve that one for a later post).
But it meant I did not see all functionality, alas. It could have saved me some time.
Anyway, at least in 11gR1 (I’ll look into 10gR2 shortly) you can change host, port, sid and password from a convenient browser screen as presented below. Nice.

BTW, works for File locations too.
BTW2, The link to this screen is perfectly hidden under the link called ‘Unknown’ at the end of the line for each location
BTW3, It is available in OWB 10gR2 as well

change_owb_loc_details


Fear of maths is a problem worth solving

Peter O'Brien - Wed, 2009-10-28 15:37
According to researchers at the University of Granada, 6 out of every 10 university students present "mathematical anxiety". This study was carried out in a sample consisting of 885 first-year students from 23 different degrees given at the UGR which include the subject of Mathematics, both compulsory and core. The sample included four of the five university fields of study: Health Sciences, Experimental Sciences, Technical Education and Social Sciences. The conclusion is that many students choose 3rd level courses different to those they preferred - and in which they would be really good in many cases – in order to avoid studying subjects connected with Mathematics. Clearly there needs to be some help with math at an early stage in life to avoid this anxiety and help people get comfortable with maths.

At first this may not appear as such a big issue for Computer Programming, particularly as the majority of the software development emphasis is on business rather than scientific solutions. It may be obvious, but it has to be pointed out that one of the key residual benefits from studying to solve math problems is the development of problem solving skills. While many of us , years later, may rarily use the algebra we study in school, the process of breaking down a problem into it's constituent parts stays with us when we go out into the real world. Where problems have vague specifications. Where there is more than one way to solve a problem. Where you run into problems you have never seen before.

There is free online math help available. To name just a couple there is:
  • http://www.math.com
  • http://www.mathway.com

Also there is a great book called Maths: A Student's Survival Guide which will be valued particularly by those who need to make up a deficiency in a specific topic or to remove the rust from their mathematics. If all this is too much to start working on your own mathematical anxiety then consider chocolate. At least you'll get something out of it!

Oracle Open World 2009 Summary

Oracle Optimizer Team - Wed, 2009-10-28 13:09
We had a great time talking to our users at Open World 2009 both at our Demogrounds booth and at our two sessions. We received a lot of interesting questions during the Optimizer Roundtable discussion, but we did not get to answer all of them due to time constraints. We plan to address the questions we received (both answered and unanswered) in future blog posts... so stay tuned. If you didn't get to attend the discussion, but have a question about the Optimizer, submit it through the email link above.

For those of you who did not get a chance to stop by our Demogrounds booth, here's a recap of the new features that we talked about. Many of the topics have already been covered in earlier blog posts.
These topics are focused on well-known pain points from earlier versions of Oracle. But we also have plenty of new optimizations in Oracle 11gR1 and 11gR2. Stay tuned for details about some of our new optimizations.

Oracle Open World 2009 Summary

Inside the Oracle Optimizer - Wed, 2009-10-28 13:09
We had a great time talking to our users at Open World 2009 both at our Demogrounds booth and at our two sessions. We received a lot of interesting questions during the Optimizer Roundtable discussion, but we did not get to answer all of them due to time constraints. We plan to address the questions we received (both answered and unanswered) in future blog posts... so stay tuned. If you didn't get to attend the discussion, but have a question about the Optimizer, submit it through the email link above.

For those of you who did not get a chance to stop by our Demogrounds booth, here's a recap of the new features that we talked about. Many of the topics have already been covered in earlier blog posts.
These topics are focused on well-known pain points from earlier versions of Oracle. But we also have plenty of new optimizations in Oracle 11gR1 and 11gR2. Stay tuned for details about some of our new optimizations.

Categories: DBA Blogs, Development

Back to......being employed

Lisa Dobson - Mon, 2009-10-26 09:43
After leaving the world of Consultancy behind in February, I had 5 months of unemployment during which time I learned 2 valuable lessons;1) I make a lousy housewife2) It is possible to survive for 5 months without new shoesBoth of these things surprised me.Thankfully I was able to find work before I drove myself and my other half completely round the twist.Since July I have been working at DurhamLisahttp://www.blogger.com/profile/16434297444320005874noreply@blogger.com10

Wintertime (again)

Freek D’Hooge - Sun, 2009-10-25 08:28

During my prior post on the effect of daylight saving settings on the Oracle scheduler, I already pointed out that it is best to set your session timezone information to a named timezone and not to an absolute offset. In this post I would like to investigate how the session timezone settings affect the sysdate, current_date, systimestamp and current_timestamp variables during the switchover to or from daylight saving time. Current_date and current_timestamp, are using the date/time information of the server on which the database runs and modify that time using the timezone settings of the session.
As with the last post, the tests where done in response to the switching from wintertime to summertime, and I’m to lazy to redo them.

In the first test, I do not explicitly set timezone information in my session.
Both the server time and the client time has been set to a couple of minutes before the swithover from wintertime to summertime:

sys@GUNNAR> alter session set nls_date_format = 'DD/MM/YYYY HH24:MI:SS';

Session altered.

sys@GUNNAR> alter session set nls_timestamp_tz_format='DD/MM/YYYY HH24:MI:SS "TZ:" TZR "DS:" TZD ';

Session altered.

sys@GUNNAR> column systimestamp format a35
sys@GUNNAR> column current_timestamp format a35
sys@GUNNAR> select sysdate, current_date, systimestamp, current_timestamp from dual;

SYSDATE             CURRENT_DATE        SYSTIMESTAMP                        CURRENT_TIMESTAMP
------------------- ------------------- ----------------------------------- -----------------------------------
29/03/2009 01:58:32 29/03/2009 01:58:32 29/03/2009 01:58:32 TZ: +01:00 DS:  29/03/2009 01:58:32 TZ: +01:00 DS:

As you can see the timezone information uses the absolute offset notation and is set to GMT +1 (which corresponds with wintertime in Belgium).
After some minutes (when the summertime came in effect), I execute the same query again:

sys@GUNNAR> select sysdate, current_date, systimestamp, current_timestamp from dual;

SYSDATE             CURRENT_DATE        SYSTIMESTAMP                        CURRENT_TIMESTAMP
------------------- ------------------- ----------------------------------- -----------------------------------
29/03/2009 03:00:18 29/03/2009 02:00:18 29/03/2009 03:00:18 TZ: +02:00 DS:  29/03/2009 02:00:18 TZ: +01:00 DS:

Both sysdate and systimestamp has jumped 1 hour in the feature and systimestamp now shows the timezone as “GMT + 2” (summertime in Belgium).
Current_date and current_timestamp both show the time without summertime corrections, but with current_timestamp the timezone information places the time in the right context.

Next, I disconnect and reconnect the session:

sys@GUNNAR> select sysdate, current_date, systimestamp, current_timestamp from dual;

SYSDATE             CURRENT_DATE        SYSTIMESTAMP                        CURRENT_TIMESTAMP
------------------- ------------------- ----------------------------------- -----------------------------------
29/03/2009 03:01:15 29/03/2009 03:01:15 29/03/2009 03:01:15 TZ: +02:00 DS:  29/03/2009 03:01:15 TZ: +02:00 DS:

This time, all 4 show the same time and timezone information (all using summertime).
The explanation for this is that the timezone information for a session is determined when the session is created, and Oracle only applies daylight saving settings when using a named timezone. So as long as the session is connected, it uses the “old” timezone of GMT +1. With sysdate and systimestamp the timezone information comes from the server, not from the client.

In the second test, I have set the ORA_SDTZ variable in the client environment to “Europe/Brussels”

sys@GUNNAR> select sysdate, current_date, systimestamp, current_timestamp from dual;

SYSDATE             CURRENT_DATE        SYSTIMESTAMP                        CURRENT_TIMESTAMP
------------------- ------------------- ----------------------------------- -----------------------------------------------
29/03/2009 01:57:37 29/03/2009 01:57:38 29/03/2009 01:57:37 TZ: +01:00 DS:  29/03/2009 01:57:37 TZ: EUROPE/BRUSSELS DS: CET

### a couple of minutes later

sys@GUNNAR> select sysdate, current_date, systimestamp, current_timestamp from dual;

SYSDATE             CURRENT_DATE        SYSTIMESTAMP                        CURRENT_TIMESTAMP
------------------- ------------------- ----------------------------------- ------------------------------------------------
29/03/2009 03:00:04 29/03/2009 03:00:04 29/03/2009 03:00:04 TZ: +02:00 DS:  29/03/2009 03:00:04 TZ: EUROPE/BRUSSELS DS: CEST

Both current_date and current_timestamp have now also jumped 1 hour in the “future” and the daylight saving settings in current_timestamp has changed from CET (Central European Time) to CEST (Central European Summer Time).
To me this shows that it is important to set the timezone of you clients correctly, even if the database is not used from different timezones.
A long running session is sufficient to pollute your data, certainly if you are using current_date as it has no timezone information.


Categories: DBA Blogs

Increased Momentum to Hybrid Cloud

Khanderao Kand - Thu, 2009-10-22 16:21
Hybrid Cloud as depicted in the following diagram is a middle path for enterprises for taking advantage of the public clouds as well as addressing the security and ownership concerns of mission critical as well as sensitive data.



Recently at OOW 2009 is SFO, Mark Benioff, CEO of Salesforce, showed agreement to the Hybrid approch.  Both Dell and SaleForce determined on this Hybrid approach.

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