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• PowerShell - grabbing values out of the registry and running them

  - by Rob Farley

  So I closed an application that runs when Windows starts up, but it doesn’t have a Start Menu entry, and I was trying to find it. Ok, I could’ve run regedit.exe, navigated through the tree and found the list of things that run when Windows starts up, but I thought I’d use PowerShell instead. PowerShell presents the registry as if it’s a volume on a disk, and you can navigate around it using commands like cd and dir. It wasn’t hard to find the folder I knew I was after – tab completion (starting the word and then hitting the Tab key) was a friend here. But unfortunately dir doesn’t list values, only subkeys (which look like folders). PS C:\Windows\system32> dir HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run PS C:\Windows\system32> Instead, I needed to use Get-Item to fetch the ‘Run’ key, and use its Property property. This listed the values in there for me, as an array of strings (I could work this out using Get-Member). PS C:\Windows\system32> (Get-Item HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run).Property QuickSet SynTPEnh Zune Launcher PS C:\Windows\system32> Ok, so the thing I wanted wasn’t in there (an app called PureText, whicih lets me Paste As Text using Windows+V). That’s ok – a simple change to use HKCU instead of HKLM (Current User instead of Local Machine), and I found it. Now to fetch the details of the application itself, using the RegistryKey method GetValue PS C:\Windows\system32> (Get-Item HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run).GetValue('PureText') "C:\Users\Rob\Utilities\PureText.exe" PS C:\Windows\system32> And finally, surrounding it in a bit of code to execute that command. That needs an ampersand and the Invoke-Expression cmdlet. PS C:\Windows\system32> '& ' + (Get-Item HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run).GetValue('PureText') | Invoke-Expression A simple bit of exploring PowerShell which will makes for a much easier way of finding and running those apps which start with Windows.

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• Merge sort. ArrayIndexOutOfBoundsException [migrated]

  - by user94892

  When I execute the program I am getting an error as stated below the program. Please help me figure out the problem.. import java.util.*; class Mergesort { public static void main(String args[]) { Scanner in= new Scanner(System.in); System.out.println("Enter the number of elements"); int n= in.nextInt(); int a[]= new int[n]; System.out.println("Enter the contents"); for(int i=0; i<n; i++) { a[i]=in.nextInt(); } a = mergesort(a,n); for(int i=0; i<n; i++) { System.out.println(a[i]); } } public static int[] mergesort(int[] x, int z) { if(z==1) { return x; } int b[]=new int[z/2]; int c[]=new int[z-z/2]; int i,j,k; for(int p=0;p<z/2; p++) { b[p]= x[p]; c[p]= x[p+z/2]; } c[z-z/2-1]= x[z-1]; b= mergesort(b,z/2); c= mergesort(c,z-z/2); for(i=0,j=0,k=0; k<z; k++) { if(b[i]<=c[j]) { x[k]=b[i]; i++; } else if( b[i]>c[j]) { x[k]=c[j]; j++; } else if(i== z/2) { x[k]= c[j]; j++; } else if(j == z-z/2) { x[k]= b[i]; i++; } } return x; } } Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1 at Mergesort.mergesort(Mergesort.java:41) at Mergesort.mergesort(Mergesort.java:36) at Mergesort.main(Mergesort.java:16)

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• Need suggestion for Mutiple Windows application design

  - by King Chan

  This was previously posted in StackOverflow, I just moved to here... I am using VS2008, MVVM, WPF, Prism to make a mutiple window CRM Application. I am using MidWinow in my MainWindow, I want Any ViewModel would able to make request to MainWindow to create/add/close MidChildWindow, ChildWindow(from WPF Toolkit), Window (the Window type). ViewModel can get the DialogResult from the ChildWindow its excutes. MainWindow have control on all opened window types. Here is my current approach: I made Dictionary of each of the windows type and stores them into MainWindow class. For 1, i.e in a CustomerInformationView, its CustomerInformationViewModel can execute EditCommand and use EventAggregator to tell MainWindow to open a new ChildWindow. CustomerInformationViewModel: CustomerEditView ceView = new CustomerEditView (); CustomerEditViewModel ceViewModel = CustomerEditViewModel (); ceView.DataContext = ceViewModel; ChildWindow cWindow = new ChildWindow(); cWindow.Content = ceView; MainWindow.EvntAggregator.GetEvent<NewWindowEvent>().Publish(new WindowEventArgs(ceViewModel.ViewModeGUID, cWindow )); cWindow.Show(); Notice that all my ViewModel will generates a Guid for help identifies the ChildWindow from MainWindow's dictionary. Since I will only be using 1 View 1 ViewModel for every Window. For 2. In CustomerInformationViewModel I can get DialogResult by OnClosing event from ChildWindow, in CustomerEditViewModel can use Guid to tell MainWindow to close the ChildWindow. Here is little question and problems: Is it good idea to use Guid here? Or should I use HashKey from ChildWindow? My MainWindows contains windows reference collections. So whenever window close, it will get notifies to remove from the collection by OnClosing event. But all the Windows itself doesn't know about its associated Guid, so when I remove it, I have to search for every KeyValuePair to compares... I still kind of feel wrong associate ViewModel's Guid for ChildWindow, it would make more sense if ChildWindow has it own ID then ViewModel associate with it... But most important, is there any better approach on this design? How can I improve this better?

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• changing drive nodes & hdparm

  - by Kalamalka Kid

  I am currently attempting to create a command that works at startup to kill the power on two of my very noisy hard drives. I have edited the etc/rc.local file to include this command: sudo hdparm -y /dev/sdc sudo hdparm -y /dev/sdd exit 0 While I think this should work, it seems the allocated drives keep switching around every time I reboot. I have sda, sdb, sdc, sdd, and sde but they keep getting jumbled around (making the drive I wish to shut different than sdd which is making the task of shutting down the right drive on start-up quite cumbersome. I had a perfectly functioning ftstab file working which disappeard, but I restored it from the back up into the etc/ dir: # <file system> <mount point> <type> <options> <dump> <pass> #Entry for /dev/sda1 : UUID=43c09daf-08a5-44f2-89b0-fc7c6f0d1e67 / ext4 errors=remount-ro 0 1 #Entry for /dev/sdd1 : UUID=443AFBAD7FE50945 /media/DX100 ntfs-3g defaults,nosuid,nodev,locale=en_CA.UTF-8 0 0 #Entry for /dev/sdb1 : UUID=FCE456F5E456B21E /media/GalaxyM83 ntfs-3g defaults,nosuid,nodev,locale=en_CA.UTF-8 0 0 #Entry for /dev/sdf1 : UUID=1CA057FDA057DBB8 /media/Holideck ntfs-3g defaults,nosuid,nodev,locale=en_CA.UTF-8 0 0 #Entry for /dev/sdc1 : UUID=7ABB49654B799D40 /media/JX3P ntfs defaults,nosuid,nodev,locale=en_CA.UTF-8 0 0 it seems every time I boot the order of the drives changes. I do not know how to resolve this. A quick workaround the problem was to go with UUID instead of the DEV letter by editing the etc/rc.local file to include: hdparm -y /dev/disk/by-uuid/443AFBAD7FE50945 hdparm -y /dev/disk/by-uuid/7ABB49654B799D40 So I thought I was in the clear, as I heard both hard drives die down during the boot sequence, BUT, as soon as I log in both drives start up again! so now I have to figure out what is making them start up again after log in, or perhaps another way to get them to turn off. Is there some kind of command i can get to execute after log in? I tried editing the startup applications to include an autossh with: autoshh - sudo hdparm -y /dev/disk/by-uuid/7ABB49654B799D40 autoshh - sudo hdparm -y /dev/disk/by-uuid/443AFBAD7FE50945 but this did not seem to work to turn off the disks after log in.

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• An Epic Question "How to call a method when the page loads"

  - by Arunkumar Ramamoorthy

  Quite often, there comes a question in OTN, with different subjects, all meaning "How to call a method when my ADF page loads?". More often, people tend to take the approach of ADF Phase Listener by overriding before/afterPhase methods.In this blog, we will go through different options in achieving it.1. Method Call Activity as default activity in Taskflow :If the application is built with taskflows, then this is the best suited approach to take. 1.a. Calling a Data Control Method :To call a Data Control method (ex: A method in AMImpl exposed as client interface), simply Drag and Drop the method as Default Method Call Activity, then draw a control flow case from the method to your page. Once after this, drop the taskflow as region in main page. When we run the main page, the Method Call Activity would be called first, and then the page will be rendered.1.b. Calling a Method in Backing Bean: To call a method in the backing bean before pageload, we can follow the similar approach as above. Instead of binding the Method Call Activity to an action/method binding in pagedef, we bind to the method. Insert a Method Call Activity (and make it as default) from the Component Palette. Double click on to select a method to bind. This approach can also be used, to perform some action in backing bean along with calling a method Data Control (just need to add bindings code in backing bean to execute DC method). 2. Using invokeAction Executable :If the application is built with pages and no taskflows are involved, then this option can be taken into consideration.In the page definition of the page, add an invokeAction Executable and bind it to the method needed to be executed. 3. Using combination of Server and Client Listeners : If the page does not have any page definition, then to call a method in backing bean, this approach can be taken. In this, a serverListener would be added at the document level, which would be calling the method in backing bean. Along with this, a clientListener would be added with "load" type (i.e will be triggered when the page loads), which would queue a serverEvent to trigger the method. 4. Using Page Phase Listener :This should be the last resort. Care should be taken when using this approach since the Phase Listener would be called for each request sent by the client.Zeeshan Baig's blog covers this scenario.

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• An Epic Question "How to call a method when the page loads"

  - by Arunkumar Ramamoorthy

  Quite often, there comes a question in OTN, with different subjects, all meaning "How to call a method when my ADF page loads?". More often, people tend to take the approach of ADF Phase Listener by overriding before/afterPhase methods.In this blog, we will go through different options in achieving it.1. Method Call Activity as default activity in Taskflow :If the application is built with taskflows, then this is the best suited approach to take. 1.a. Calling a Data Control Method :To call a Data Control method (ex: A method in AMImpl exposed as client interface), simply Drag and Drop the method as Default Method Call Activity, then draw a control flow case from the method to your page. Once after this, drop the taskflow as region in main page. When we run the main page, the Method Call Activity would be called first, and then the page will be rendered.1.b. Calling a Method in Backing Bean: To call a method in the backing bean before pageload, we can follow the similar approach as above. Instead of binding the Method Call Activity to an action/method binding in pagedef, we bind to the method. Insert a Method Call Activity (and make it as default) from the Component Palette. Double click on to select a method to bind. This approach can also be used, to perform some action in backing bean along with calling a method Data Control (just need to add bindings code in backing bean to execute DC method). 2. Using invokeAction Executable :If the application is built with pages and no taskflows are involved, then this option can be taken into consideration.In the page definition of the page, add an invokeAction Executable and bind it to the method needed to be executed. 3. Using combination of Server and Client Listeners : If the page does not have any page definition, then to call a method in backing bean, this approach can be taken. In this, a serverListener would be added at the document level, which would be calling the method in backing bean. Along with this, a clientListener would be added with "load" type (i.e will be triggered when the page loads), which would queue a serverEvent to trigger the method. 4. Using Page Phase Listener :This should be the last resort. Care should be taken when using this approach since the Phase Listener would be called for each request sent by the client.Zeeshan Baig's blog covers this scenario.

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• The Case of the Missing Date/Time Stamp: Reporting Services 2008 R2 Snapshots

  - by smisner

  This week I stumbled upon an undocumented “feature” in SQL Server 2008 R2 Reporting Services as I was preparing a demonstration on how to set up and use report snapshots. If you’re familiar with the main changes in this latest release of Reporting Services, you probably already know that Report Manager got a facelift this time around. Although this facelift was generally a good thing, one of the casualties – in my opinion – is the loss of the snapshot label that served two purposes… First, it flagged the report as a snapshot. Second, it let you know when that snapshot was created. As part of my standard operating procedure when demonstrating report snapshots, I point out this label, so I was rather taken aback when I didn’t see it in the demonstration I was preparing. It sort of upset my routine, and I’m rather partial to my routines. I thought perhaps I wasn’t looking in the right place and changed Report Manager from Tile View to Detail View, but no – that label was still missing. In the grand scheme of life, it’s not an earth-shattering change, but you’ll have to look at the Modified Date in Details View to know when the snapshot was run. Or hope that the report developer included a textbox to show the execution time in the report. (Hint: this is a good time to add this to your list of report development best practices, whether a report gets set up as a report snapshot or not!) A snapshot from the past In case you don’t remember how a snapshot appeared in Report Manager back in the old days (of SQL Server 2008 and earlier), here’s an image I snagged from my Reporting Services 2008 Step by Step manuscript: A snapshot in the present A report server running in SharePoint integrated mode had no such label. There you had to rely on the Report Modified date-time stamp to know the snapshot execution time. So I guess all platforms are now consistent. Here’s a screenshot of Report Manager in the 2008 R2 version. One of these is a snapshot and the rest execute on demand. Can you tell which is the snapshot? Consider descriptions as an alternative So my report snapshot demonstration has one less step, and I’ll need to edit the Denali version of the Step by Step book. Things are simpler this way, but I sure wish we had an easier way to identify the execution methods of the reports. Consider using the description field to alert users that the report is a snapshot. It might save you a few questions about why the data isn’t up-to-date if the users know that something changed in the source of the report. Notice that the full description doesn’t display in Tile View, so keep it short and sweet or instruct users to open Details View to see the entire description.

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• Introducing Windows Azure Mobile Services

  - by Clint Edmonson

  Today I’m excited to share that the Windows Azure Mobile Services public preview is now available. This preview provides a turnkey backend cloud solution designed to accelerate connected client app development. These services streamline the development process by enabling you to leverage the cloud for common mobile application scenarios such as structured storage, user authentication and push notifications. If you’re building a Windows 8 app and want a fast and easy path to creating backend cloud services, this preview provides the capabilities you need. You to take advantage of the cloud to build and deploy modern apps for Windows 8 devices in anticipation of general availability on October 26th. Subsequent preview releases will extend support to iOS, Android, and Windows Phone. Features The preview makes it fast and easy to create cloud services for Windows 8 applications within minutes. Here are the key benefits:  Rapid development: configure a straightforward and secure backend in less than five minutes. Create modern mobile apps: common Windows Azure plus Windows 8 scenarios that Windows Azure Mobile Services preview will support include:  Automated Service API generation providing CRUD functionality and dynamic schematization on top of Structured Storage Structured Storage with powerful query support so a Windows 8 app can seamlessly connect to a Windows Azure SQL database Integrated Authentication so developers can configure user authentication via Windows Live Push Notifications to bring your Windows 8 apps to life with up to date and relevant information Access structured data: connect to a Windows Azure SQL database for simple data management and dynamically created tables. Easy to set and manage permissions. Pricing One of the key things that we’ve consistently heard from developers about using Windows Azure with mobile applications is the need for a low cost and simple offer. The simplest way to describe the pricing for Windows Azure Mobile Services at preview is that it is the same as Windows Azure Websites during preview. What’s FREE? Run up to 10 Mobile Services for free in a multitenant environment Free with valid Windows Azure Free Trial 1GB SQL Database Unlimited ingress 165MB/day egress  What do I pay for? Scaling up to dedicated VMs Once Windows Azure Free Trial expires - SQL Database and egress     Getting Started To start using Mobile Services, you will need to sign up for a Windows Azure free trial, if you have not done so already.  If you already have a Windows Azure account, you will need to request to enroll in this preview feature. Once you’ve enrolled, this getting started tutorial will walk you through building your first Windows 8 application using the preview’s services. The developer center contains more resources to teach you how to: Validate and authorize access to data using easy scripts that execute securely, on the server Easily authenticate your users via Windows Live Send toast notifications and update live tiles in just a few lines of code Our pricing calculator has also been updated for calculate costs for these new mobile services. Questions? Ask in the Windows Azure Forums. Feedback? Send it to [email protected].

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• PASS Summit – looking back on my first time

  - by Fatherjack

    So I was lucky enough to get my first experience of PASS Summit this year and took some time beforehand to read some blogs and reference material to get an idea on what to do and how to get the best out of my visit. Having been to other conferences – technical and non-technical – I had a reasonable idea on the routine and what to expect in general. Here is a list of a few things that I have learned/remembered as the week has gone by. Wear comfortable shoes. This actually needs to be broadened to Take several pairs of comfortable shoes. You will be spending many many hours, for several days one after another. Having comfortable feet that can literally support you for the duration will make the week in general a whole lot better. Not only at the conference but getting to and from you could well be walking. In the evenings you will be walking around town and standing talking in various bars and clubs. Looking back, on some days I was on my feet for over 20 hours. Make friends. This is a given for the long term benefits it brings but there is also an immediate reward in being at a conference with a friend or two. Some events are bigger and more popular than others and some have the type of session that every single attendee will want to be in. This is great for those that get in but if you are in the bathroom or queuing for coffee and you miss out it sucks. Having a friend that can get in to a room and reserve you a seat is a great advantage to make sure you get the content that you want to see and still have the coffee that you need. Don’t go to every session you want to see This might sound counter intuitive and it relies on the sessions being recorded in some way to guarantee you don’t totally miss out. Both PASS Summit and SQL Bits sessions are recorded (summit is audio, SQLBits is video) and this means that if you get into a good conversation with someone over a coffee you don’t have to break it up to go to a session. Obviously there is a trade-off here and you need to decide on the tipping point for yourself but a conversation at a place like this could make a big difference to the next contract or employer you have or it might simply be great catching up with some friends you don’t see so often. Go to at least one session you don’t want to Again, this will seem to be contrary to normal logic but there is no reason why you shouldn’t learn about a part of SQL Server that isn’t part of your daily routine. Not only will you learn something new but you will also pick up on the feelings and attitudes of the people in the session. So, if you are a DBA, head off to a BI session and so on. You’ll hear BI speakers speaking to a BI audience and get to understand their point of view and reasoning for making the decisions they do. You will also appreciate the way that your decisions and instructions affect the way they have to work. This will help you a lot when you are on a project, working with multiple teams and make you all more productive. Socialise While you are at the conference venue, speak to people. Ask questions, be interested in whoever you are speaking to. You get chances to talk to new friends at breakfast, dinner and every break between sessions. The only people that might not talk to you would be speakers that are about to go and give a session, in most cases speakers like peace and quiet before going on stage. Other than that the people around you are just waiting for someone to talk to them so make the first move. There is a whole lot going on outside of the conference hours and you should make an effort to join in with some of this too. At karaoke evenings or just out for a quiet drink with a few of the people you meet at the conference. Either way, don’t be a recluse and hide in your room or be alone out in the town. Don’t talk to people Once again this sounds wrong but stay with me. I have spoken to a number of speakers since Summit 2013 finished and they have all mentioned the time it has taken them to move about the conference venue due to people stopping them for a chat or to ask a question. 45 minutes to walk from a session room to the speaker room in one case. Wow. While none of the speakers were upset about this sort of delay I think delegates should take the situation into account and possibly defer their question to an email or to a time when the person they want is clearly less in demand. Give them a chance to enjoy the conference in the same way that you are, they may actually want to go to a session or just have a rest after giving their session – talking for 75 minutes is hard work, taking an extra 45 minutes right after is unbelievable. I certainly hope that they get good feedback on their sessions and perhaps if you spoke to a speaker outside a session you can give them a mention in the ‘any other comments’ part of the feedback, just to convey your gratitude for them giving up their time and expertise for free. Say thank you I just mentioned giving the speakers a clear, visible ‘thank you’ in the feedback but there are plenty of people that help make any conference the success it is that would really appreciate hearing that their efforts are valued. People on the registration desk, volunteers giving schedule guidance and directions, people on the community zone are all volunteers giving their time to help you have the best experience possible. Send an email to PASS and convey your thoughts about the work that was done. Maybe you want to be a volunteer next time so you could enquire how you get into that position at the same time. This isn’t an exclusive list and you may agree or disagree with the points I have made, please add anything you think is good advice in the comments. I’d like to finish by saying a huge thank you to all the people involved in planning, facilitating and executing the PASS Summit 2013, it was an excellent event and I know many others think it was a totally worthwhile event to attend.

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• EJB Named Criteria - Apply bind variable in Backingbean

  - by Deepak Siddappa

  EJB Named criteria are predefined and reusable where-clause definitions that are dynamically applied to a ViewObject query. Here we often use to filter the ViewObject SQL statement query based on Where Clause conditions.Take a scenario where we need to filter the SQL statements query based on Where Clause conditions, instead of playing with SQL statements use the EJB Named Criteria which is supported by default in ADF and set the Bind Variable parameter at run time.You can download the sample workspace from here [Runs with Oracle JDeveloper 11.1.2.0.0 (11g R2) + HR Schema] Implementation StepsCreate Java EE Web Application with entity based on Employees table, then create a session bean and data control for the session bean.Open the DataControls.dcx file and create sparse xml for as shown below. In sparse xml navigate to Named criteria tab -> Bind Variable section, create binding variable deptId. Now create a named criteria and map the query attributes to the bind variable. In the ViewController create index.jspx page, from data control palette drop employeesFindAll->Named Criteria->EmployeesCriteria->Table as ADF Read-Only Filtered Table and create the backingBean as "IndexBean".Open the index.jspx page and remove the "filterModel" binding from the table, add <af:inputText />, command button and bind them to backingBean. For command button create the actionListener as "applyEmpCriteria" and add below code to the file. public void applyEmpCriteria(ActionEvent actionEvent) { DCIteratorBinding dc = (DCIteratorBinding)evaluteEL("#{bindings.employeesFindAllIterator}"); ViewObject vo = dc.getViewObject(); vo.applyViewCriteria(vo.getViewCriteriaManager().getViewCriteria("EmployeesCriteria")); vo.ensureVariableManager().setVariableValue("deptId", this.getDeptId().getValue()); vo.executeQuery(); } /** * Programmtic evaluation of EL * * @param el EL to evalaute * @return Result of the evalutaion */ public Object evaluteEL(String el) { FacesContext fctx = FacesContext.getCurrentInstance(); ELContext elContext = fctx.getELContext(); Application app = fctx.getApplication(); ExpressionFactory expFactory = app.getExpressionFactory(); ValueExpression valExp = expFactory.createValueExpression(elContext, el, Object.class); return valExp.getValue(elContext); } Run the index.jspx page, enter departmentId value as 90 and click in ApplyEmpCriteria button. Now the bind variable for the Named criteria will be applied at runtime in the backing bean and it will re-execute ViewObject query to filter based on where clause condition.

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• The most dangerous SQL Script in the world!

  - by DrJohn

  In my last blog entry, I outlined how to automate SQL Server database builds from concatenated SQL Scripts. However, I did not mention how I ensure the database is clean before I rebuild it. Clearly a simple DROP/CREATE DATABASE command would suffice; but you may not have permission to execute such commands, especially in a corporate environment controlled by a centralised DBA team. However, you should at least have database owner permissions on the development database so you can actually do your job! Then you can employ my universal "drop all" script which will clear down your database before you run your SQL Scripts to rebuild all the database objects. Why start with a clean database? During the development process, it is all too easy to leave old objects hanging around in the database which can have unforeseen consequences. For example, when you rename a table you may forget to delete the old table and change all the related views to use the new table. Clearly this will mean an end-user querying the views will get the wrong data and your reputation will take a nose dive as a result! Starting with a clean, empty database and then building all your database objects using SQL Scripts using the technique outlined in my previous blog means you know exactly what you have in your database. The database can then be repopulated using SSIS and bingo; you have a data mart "to go". My universal "drop all" SQL Script To ensure you start with a clean database run my universal "drop all" script which you can download from here: 100_drop_all.zip By using the database catalog views, the script finds and drops all of the following database objects: Foreign key relationships Stored procedures Triggers Database triggers Views Tables Functions Partition schemes Partition functions XML Schema Collections Schemas Types Service broker services Service broker queues Service broker contracts Service broker message types SQLCLR assemblies There are two optional sections to the script: drop users and drop roles. You may use these at your peril, particularly as you may well remove your own permissions! Note that the script has a verbose mode which displays the SQL commands it is executing. This can be switched on by setting @debug=1. Running this script against one of the system databases is certainly not recommended! So I advise you to keep a USE database statement at the top of the file. Good luck and be careful!!

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• Programming Language, Turing Completeness and Turing Machine

  - by Amumu

  A programming language is said to be Turing Completeness if it can successfully simulate a universal TM. Let's take functional programming language for example. In functional programming, function has highest priority over anything. You can pass functions around like any primitives or objects. This is called first class function. In functional programming, your function does not produce side effect i.e. output strings onto screen, change the state of variables outside of its scope. Each function has a copy of its own objects if the objects are passed from the outside, and the copied objects are returned once the function finishes its job. Each function written purely in functional style is completely independent to anything outside of it. Thus, the complexity of the overall system is reduced. This is referred as referential transparency. In functional programming, each function can have its local variables kept its values even after the function exits. This is done by the garbage collector. The value can be reused the next time the function is called again. This is called memoization. A function usually should solve only one thing. It should model only one algorithm to answer a problem. Do you think that a function in a functional language with above properties simulate a Turing Machines? Functions (= algorithms = Turing Machines) are able to be passed around as input and returned as output. TM also accepts and simulate other TMs Memoization models the set of states of a Turing Machine. The memorized variables can be used to determine states of a TM (i.e. which lines to execute, what behavior should it take in a give state ...). Also, you can use memoization to simulate your internal tape storage. In language like C/C++, when a function exits, you lose all of its internal data (unless you store it elsewhere outside of its scope). The set of symbols are the set of all strings in a programming language, which is the higher level and human-readable version of machine code (opcode) Start state is the beginning of the function. However, with memoization, start state can be determined by memoization or if you want, switch/if-else statement in imperative programming language. But then, you can't Final accepting state when the function returns a value, or rejects if an exception happens. Thus, the function (= algorithm = TM) is decidable. Otherwise, it's undecidable. I'm not sure about this. What do you think? Is my thinking true on all of this? The reason I bring function in functional programming because I think it's closer to the idea of TM. What experience with other programming languages do you have which make you feel the idea of TM and the ideas of Computer Science in general? Can you specify how you think?

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• laptop crashed: why?

  - by sds

  my linux (ubuntu 12.04) laptop crashed, and I am trying to figure out why. # last sds pts/4 :0 Tue Sep 4 10:01 still logged in sds pts/3 :0 Tue Sep 4 10:00 still logged in reboot system boot 3.2.0-29-generic Tue Sep 4 09:43 - 11:23 (01:40) sds pts/8 :0 Mon Sep 3 14:23 - crash (19:19) this seems to indicate a crash at 09:42 (= 14:23+19:19). as per another question, I looked at /var/log: auth.log: Sep 4 09:17:02 t520sds CRON[32744]: pam_unix(cron:session): session closed for user root Sep 4 09:43:17 t520sds lightdm: pam_unix(lightdm:session): session opened for user lightdm by (uid=0) no messages file syslog: Sep 4 09:24:19 t520sds kernel: [219104.819975] CPU0: Package power limit normal Sep 4 09:43:16 t520sds kernel: imklog 5.8.6, log source = /proc/kmsg started. kern.log: Sep 4 09:24:19 t520sds kernel: [219104.819969] CPU1: Package power limit normal Sep 4 09:24:19 t520sds kernel: [219104.819971] CPU2: Package power limit normal Sep 4 09:24:19 t520sds kernel: [219104.819974] CPU3: Package power limit normal Sep 4 09:24:19 t520sds kernel: [219104.819975] CPU0: Package power limit normal Sep 4 09:43:16 t520sds kernel: imklog 5.8.6, log source = /proc/kmsg started. Sep 4 09:43:16 t520sds kernel: [ 0.000000] Initializing cgroup subsys cpuset Sep 4 09:43:16 t520sds kernel: [ 0.000000] Initializing cgroup subsys cpu I had a computation running until 9:24, but the system crashed 18 minutes later! kern.log has many pages of these: Sep 4 09:43:16 t520sds kernel: [ 0.000000] total RAM covered: 8086M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 64K num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 128K num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 256K num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 512K num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 1M num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 2M num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 4M num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 8M num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 16M num_reg: 10 lose cover RAM: 38M Sep 4 09:43:16 t520sds kernel: [ 0.000000] *BAD*gran_size: 64K chunk_size: 32M num_reg: 10 lose cover RAM: -16M Sep 4 09:43:16 t520sds kernel: [ 0.000000] *BAD*gran_size: 64K chunk_size: 64M num_reg: 10 lose cover RAM: -16M Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 128M num_reg: 10 lose cover RAM: 0G Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 256M num_reg: 10 lose cover RAM: 0G Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 512M num_reg: 10 lose cover RAM: 0G Sep 4 09:43:16 t520sds kernel: [ 0.000000] gran_size: 64K chunk_size: 1G num_reg: 10 lose cover RAM: 0G Sep 4 09:43:16 t520sds kernel: [ 0.000000] *BAD*gran_size: 64K chunk_size: 2G num_reg: 10 lose cover RAM: -1G does this mean that my RAM is bad?! it also says Sep 4 09:43:16 t520sds kernel: [ 2.944123] EXT4-fs (sda1): INFO: recovery required on readonly filesystem Sep 4 09:43:16 t520sds kernel: [ 2.944126] EXT4-fs (sda1): write access will be enabled during recovery Sep 4 09:43:16 t520sds kernel: [ 3.088001] firewire_core: created device fw0: GUID f0def1ff8fbd7dff, S400 Sep 4 09:43:16 t520sds kernel: [ 8.929243] EXT4-fs (sda1): orphan cleanup on readonly fs Sep 4 09:43:16 t520sds kernel: [ 8.929249] EXT4-fs (sda1): ext4_orphan_cleanup: deleting unreferenced inode 658984 ... Sep 4 09:43:16 t520sds kernel: [ 9.343266] EXT4-fs (sda1): ext4_orphan_cleanup: deleting unreferenced inode 525343 Sep 4 09:43:16 t520sds kernel: [ 9.343270] EXT4-fs (sda1): 56 orphan inodes deleted Sep 4 09:43:16 t520sds kernel: [ 9.343271] EXT4-fs (sda1): recovery complete Sep 4 09:43:16 t520sds kernel: [ 9.645799] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null) does this mean my HD is bad? As per FaultyHardware, I tried smartctl -l selftest, which uncovered no errors: smartctl 5.41 2011-06-09 r3365 [x86_64-linux-3.2.0-30-generic] (local build) Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Model Family: Seagate Momentus 7200.4 Device Model: ST9500420AS Serial Number: 5VJE81YK LU WWN Device Id: 5 000c50 0440defe3 Firmware Version: 0003LVM1 User Capacity: 500,107,862,016 bytes [500 GB] Sector Size: 512 bytes logical/physical Device is: In smartctl database [for details use: -P show] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 4 Local Time is: Mon Sep 10 16:40:04 2012 EDT SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED See vendor-specific Attribute list for marginal Attributes. General SMART Values: Offline data collection status: (0x82) Offline data collection activity was completed without error. Auto Offline Data Collection: Enabled. Self-test execution status: ( 0) The previous self-test routine completed without error or no self-test has ever been run. Total time to complete Offline data collection: ( 0) seconds. Offline data collection capabilities: (0x7b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. Offline surface scan supported. Self-test supported. Conveyance Self-test supported. Selective Self-test supported. SMART capabilities: (0x0003) Saves SMART data before entering power-saving mode. Supports SMART auto save timer. Error logging capability: (0x01) Error logging supported. General Purpose Logging supported. Short self-test routine recommended polling time: ( 1) minutes. Extended self-test routine recommended polling time: ( 109) minutes. Conveyance self-test routine recommended polling time: ( 2) minutes. SCT capabilities: (0x103b) SCT Status supported. SCT Error Recovery Control supported. SCT Feature Control supported. SCT Data Table supported. SMART Attributes Data Structure revision number: 10 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 117 099 034 Pre-fail Always - 162843537 3 Spin_Up_Time 0x0003 100 100 000 Pre-fail Always - 0 4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 571 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0 7 Seek_Error_Rate 0x000f 069 060 030 Pre-fail Always - 17210154023 9 Power_On_Hours 0x0032 095 095 000 Old_age Always - 174362787320258 10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 571 184 End-to-End_Error 0x0032 100 100 099 Old_age Always - 0 187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0 188 Command_Timeout 0x0032 100 100 000 Old_age Always - 1 189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0 190 Airflow_Temperature_Cel 0x0022 061 043 045 Old_age Always In_the_past 39 (0 11 44 26) 191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age Always - 84 192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 20 193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 2434 194 Temperature_Celsius 0x0022 039 057 000 Old_age Always - 39 (0 15 0 0) 195 Hardware_ECC_Recovered 0x001a 041 041 000 Old_age Always - 162843537 196 Reallocated_Event_Count 0x000f 095 095 030 Pre-fail Always - 4540 (61955, 0) 197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 254 Free_Fall_Sensor 0x0032 100 100 000 Old_age Always - 0 SMART Error Log Version: 1 No Errors Logged SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Extended offline Completed without error 00% 4545 - SMART Selective self-test log data structure revision number 1 SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS 1 0 0 Not_testing 2 0 0 Not_testing 3 0 0 Not_testing 4 0 0 Not_testing 5 0 0 Not_testing Selective self-test flags (0x0): After scanning selected spans, do NOT read-scan remainder of disk. If Selective self-test is pending on power-up, resume after 0 minute delay. Googling for the messages proved inconclusive, I can't even figure out whether the messages are routine or catastrophic. So, what do I do now?

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• Using a SQL Prompt snippet with template parameters

  - by SQLDev

  As part of my product management role I regularly attend trade shows and man the Red Gate booth in the vendor exhibition hall. Amongst other things this involves giving product demos to customers. Our latest demo involves SQL Source Control and SQL Test in a continuous integration environment. In order to demonstrate quite how easy it is to set up our tools from scratch we start the demo by creating an entirely new database to link to source control, using an individual database name for each conference attendee. In SQL Server Management Studio this can be done either by selecting New Database from the Object Explorer or by executing “CREATE DATABASE DemoDB_John” in a query window. We recently extended the demo to include SQL Test. This uses an open source SQL Server unit testing framework called tSQLt (www.tsqlt.org), which has a CLR object that requires EXTERNAL_ACCESS to be set as follows: ALTER DATABASE DemoDB_John SET TRUSTWORTHY ON This isn’t hard to do, but if you’re giving demo after demo, this two-step process soon becomes tedious. This is where SQL Prompt snippets come into their own. I can create a snippet named create_demo_db for this following: CREATE DATABASE DemoDB_John GO USE DemoDB_John GO ALTER DATABASE DemoDB_John SET TRUSTWORTHY ON Now I just have to type the first few characters of the snippet name, select the snippet from SQL Prompt’s candidate list, and execute the code. Simple! The problem is that this can only work once due to the hard-coded database name. Luckily I can leverage a nice feature in SQL Server Management Studio called Template Parameters. If I modify my snippet to be: CREATE DATABASE <DBName,, DemoDB_> GO USE <DBName,, DemoDB_> GO ALTER DATABASE <DBName,, DemoDB_> SET TRUSTWORTHY ON Once I’ve invoked the snippet, I can press Ctrl-Shift-M, which calls up the Specify Values for Template Parameters dialog, where I can type in my database name just once. Now you can click OK and run the query. Easy. Ideally I’d like for SQL Prompt to auto-invoke the Template Parameter dialog for all snippets where it detects the angled bracket syntax, but typing in the keyboard shortcut is a small price to pay for the time savings.

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• Configuring Full-Text Search for pdf and docx files

  - by Lukasz Kurylo

  I think in may I was creating a little filters module based on Full Text-Search. I have configured my dev machine, the same for two testing servers – in our company for internal testing before we deployed it to client, and then on the testing client server. Until last week this build  was still on the testing server and finally we got feedback that we can deploy it on the production one. I only say that, I lost half a day because I had not correctly remembered what I was doing to configure the FTS on the previous servers and I had no notes for that. I foolishly believed in my memory. Lesson learned.   For future reference a bunch of steps to configure the FTS for searching in *.pdf and *.docx files (and by the way in other Office files like *.xlsx).   1. From the page (link) download and install the *.pdf IFilter for FTS. 2. To the PATH global system variable add path to the catalog, where you installed the plugin. Default for this version is: C:\Program Files\Adobe\Adobe PDF iFilter 9 for 64-bit platforms\bin 3. From the page (link) download a FilterPackx64.exe and install it. 4. Now from SSMS execute the following procedures: -sp_fulltext_service 'load_os_resources',1 -sp_fulltext_service 'verify_signature', 0 5. Restart the server 6. Now we must check if the plugins are visible: -select document_type, path from sys.fulltext_document_types where document_type = '.pdf' -select document_type, path from sys.fulltext_document_types where document_type = '.docx' 7. If we see a result, then we can assume that everything is ok*. 8. Right now we can create a catalog for FTS and indexes on appropriate columns.     *I lost a lot of hours to find out, why the plugin for the *.pdf files wasn’t indexed any file in the database, but in the sys.fulltext_document_types table there was available a line for this plugin. After the deeper investigation I found that the *.pdf files actually were indexed. At least the EOF sign was added to the indexes and nothing more for each file. In the end the problem was that, I forgot to add the /bin in the path to the plugin in PATH variable..

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• CPU Utilization LAMP stack

  - by Max

  We've got an ec2 m2.4xlarge running Magento (centos 5.6, httpd 2.2, php 5.2.17 with eaccelerator 0.9.5.3, mysql 5.1.52). Right now we're getting a large traffic spike, and our top looks like this: top - 09:41:29 up 31 days, 1:12, 1 user, load average: 120.01, 129.03, 113.23 Tasks: 1190 total, 18 running, 1172 sleeping, 0 stopped, 0 zombie Cpu(s): 97.3%us, 1.8%sy, 0.0%ni, 0.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.4%st Mem: 71687720k total, 36898928k used, 34788792k free, 49692k buffers Swap: 880737784k total, 0k used, 880737784k free, 1586524k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2433 mysql 15 0 23.6g 4.5g 7112 S 564.7 6.6 33607:34 mysqld 24046 apache 16 0 411m 65m 28m S 26.4 0.1 0:09.05 httpd 24360 apache 15 0 410m 60m 25m S 26.4 0.1 0:03.65 httpd 24993 apache 16 0 410m 57m 21m S 26.1 0.1 0:01.41 httpd 24838 apache 16 0 428m 74m 20m S 24.8 0.1 0:02.37 httpd 24359 apache 16 0 411m 62m 26m R 22.3 0.1 0:08.12 httpd 23850 apache 15 0 411m 64m 27m S 16.8 0.1 0:14.54 httpd 25229 apache 16 0 404m 46m 17m R 10.2 0.1 0:00.71 httpd 14594 apache 15 0 404m 63m 34m S 8.4 0.1 1:10.26 httpd 24955 apache 16 0 404m 50m 21m R 8.4 0.1 0:01.66 httpd 24313 apache 16 0 399m 46m 22m R 8.1 0.1 0:02.30 httpd 25119 apache 16 0 411m 59m 23m S 6.8 0.1 0:01.45 httpd Questions: Would giving msyqld more memory help it cache queries and react faster? If so, how? Other than splitting mysql and php to separate servers (which we're about to do) is there anything else we could/should be doing? Thanks! UPDATE: Here's our my.cnf along with the output of mysqltuner. It looks like a cache problem. Thanks again! # cat /etc/my.cnf [client] port = **** socket = /var/lib/mysql/mysql.sock [mysqld] datadir=/mnt/persistent/mysql port=**** socket=/var/lib/mysql/mysql.sock key_buffer = 512M max_allowed_packet = 64M table_cache = 1024 sort_buffer_size = 8M read_buffer_size = 4M read_rnd_buffer_size = 2M myisam_sort_buffer_size = 64M thread_cache_size = 128M tmp_table_size = 128M join_buffer_size = 1M query_cache_limit = 2M query_cache_size= 64M query_cache_type = 1 max_connections = 1000 thread_stack = 128K thread_concurrency = 48 log-bin=mysql-bin server-id = 1 wait_timeout = 300 innodb_data_home_dir = /mnt/persistent/mysql/ innodb_data_file_path = ibdata1:10M:autoextend innodb_buffer_pool_size = 20G innodb_additional_mem_pool_size = 20M innodb_log_file_size = 64M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 innodb_thread_concurrency = 48 ft_min_word_len=3 [myisamchk] ft_min_word_len=3 key_buffer = 128M sort_buffer_size = 128M read_buffer = 2M write_buffer = 2M # ./mysqltuner.pl >> MySQLTuner 1.2.0 - Major Hayden <[email protected]> >> Bug reports, feature requests, and downloads at http://mysqltuner.com/ >> Run with '--help' for additional options and output filtering -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.1.52-log [OK] Operating on 64-bit architecture -------- Storage Engine Statistics ------------------------------------------- [--] Status: +Archive -BDB +Federated +InnoDB -ISAM -NDBCluster [--] Data in MyISAM tables: 2G (Tables: 26) [--] Data in InnoDB tables: 749M (Tables: 250) [!!] Total fragmented tables: 262 -------- Security Recommendations ------------------------------------------- -------- Performance Metrics ------------------------------------------------- [--] Up for: 31d 2h 30m 38s (680M q [253.371 qps], 2M conn, TX: 4825B, RX: 236B) [--] Reads / Writes: 89% / 11% [--] Total buffers: 20.6G global + 15.1M per thread (1000 max threads) [OK] Maximum possible memory usage: 35.4G (51% of installed RAM) [OK] Slow queries: 0% (35K/680M) [OK] Highest usage of available connections: 53% (537/1000) [OK] Key buffer size / total MyISAM indexes: 512.0M/457.2M [OK] Key buffer hit rate: 100.0% (9B cached / 264K reads) [OK] Query cache efficiency: 42.3% (260M cached / 615M selects) [!!] Query cache prunes per day: 4384652 [OK] Sorts requiring temporary tables: 0% (1K temp sorts / 38M sorts) [!!] Joins performed without indexes: 100404 [OK] Temporary tables created on disk: 17% (7M on disk / 45M total) [OK] Thread cache hit rate: 99% (537 created / 2M connections) [!!] Table cache hit rate: 0% (1K open / 946K opened) [OK] Open file limit used: 9% (453/5K) [OK] Table locks acquired immediately: 99% (758M immediate / 758M locks) [OK] InnoDB data size / buffer pool: 749.3M/20.0G -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance Enable the slow query log to troubleshoot bad queries Adjust your join queries to always utilize indexes Increase table_cache gradually to avoid file descriptor limits Variables to adjust: query_cache_size (> 64M) join_buffer_size (> 1.0M, or always use indexes with joins) table_cache (> 1024)

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• Wrong statistics in AUX_STATS$ might puzzle the optimizer

  - by Mike Dietrich

  We do recommend the creation of System Statistics for quite a long time. Since Oracle 9i the optimizer works with a CPU and IO cost based model. And in order to give the optimizer some knowledge about the IO subsystem's performance and throughput - once System Statistics are collected - they'll get stored in AUX_STATS$. For this purpose in the old Oracle 9i days some default values had been defined - and you'll still find those defaults in Oracle Database 11g Release 2 in AUX_STATS$. But these old values don't reflect the performance of modern IO systems. So it might be a good best practice post upgrade to create fresh System Statistics if you haven't done this before.  You can collect System Statistics with: exec DBMS_STATS.GATHER_SYSTEM_STATS('start'); and end it later by executing: exec DBMS_STATS.GATHER_SYSTEM_STATS('stop'); You could also run DBMS_STATS.GATHER_SYSTEM_STATS('interval', interval=>N) instead where N is the number of minutes when statistics gathering is stopped automatically. Please make sure you'll do this on a real workload period. It won't make sense to gather these values while the database is in an idle state. You should do this ideally for several hours. It doesn't affect performance in a negative way as the values are anyway collected in V$SYSSTAT and V$SESSTAT. And in case you'd like to delete the stats and revert to the old default values you'd simply execute:exec DBMS_STATS.DELETE_SYSTEM_STATS; The tricky thing in Oracle Database 11.2 - and that's why I'm actually writing this blog post today - is bug9842771. This leads to wrong values in AUX_STATS$ for SREADTIM and MREADTIM by factor 1000 guiding the optimizer sometimes into the totally wrong directon. The workaround is to overwrite these values manually and divide them by 1000. Use the DBMS_STATS.SET_SYSTEM_STATS procedure. See this MOS Note:9842771.8 for the above bug for some further information. This issue is fixed in Oracle Database 11.2.0.3 and above. To get some background information about the statistics collected in please read this section in the Oracle Database 11.2 Performance Tuning Guide. And gathering System Statistics might have some implication if you have mixed workloads - and interacts with DB_FILE_MULTIBLOCK_READ_COUNT. For more information please read section 13.4.1.2.

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• Function Folding in #PowerQuery

  - by Darren Gosbell

  Originally posted on: http://geekswithblogs.net/darrengosbell/archive/2014/05/16/function-folding-in-powerquery.aspxLooking at a typical Power Query query you will noticed that it's made up of a number of small steps. As an example take a look at the query I did in my previous post about joining a fact table to a slowly changing dimension. It was roughly built up of the following steps: Get all records from the fact table Get all records from the dimension table do an outer join between these two tables on the business key (resulting in an increase in the row count as there are multiple records in the dimension table for each business key) Filter out the excess rows introduced in step 3 remove extra columns that are not required in the final result set. If Power Query was to execute a query like this literally, following the same steps in the same order it would not be overly efficient. Particularly if your two source tables were quite large. However Power Query has a feature called function folding where it can take a number of these small steps and push them down to the data source. The degree of function folding that can be performed depends on the data source, As you might expect, relational data sources like SQL Server, Oracle and Teradata support folding, but so do some of the other sources like OData, Exchange and Active Directory. To explore how this works I took the data from my previous post and loaded it into a SQL database. Then I converted my Power Query expression to source it's data from that database. Below is the resulting Power Query which I edited by hand so that the whole thing can be shown in a single expression: let     SqlSource = Sql.Database("localhost", "PowerQueryTest"),     BU = SqlSource{[Schema="dbo",Item="BU"]}[Data],     Fact = SqlSource{[Schema="dbo",Item="fact"]}[Data],     Source = Table.NestedJoin(Fact,{"BU_Code"},BU,{"BU_Code"},"NewColumn"),     LeftJoin = Table.ExpandTableColumn(Source, "NewColumn"                                   , {"BU_Key", "StartDate", "EndDate"}                                   , {"BU_Key", "StartDate", "EndDate"}),     BetweenFilter = Table.SelectRows(LeftJoin, each (([Date] >= [StartDate]) and ([Date] <= [EndDate])) ),     RemovedColumns = Table.RemoveColumns(BetweenFilter,{"StartDate", "EndDate"}) in     RemovedColumns If the above query was run step by step in a literal fashion you would expect it to run two queries against the SQL database doing "SELECT * …" from both tables. However a profiler trace shows just the following single SQL query: select [_].[BU_Code],     [_].[Date],     [_].[Amount],     [_].[BU_Key] from (     select [$Outer].[BU_Code],         [$Outer].[Date],         [$Outer].[Amount],         [$Inner].[BU_Key],         [$Inner].[StartDate],         [$Inner].[EndDate]     from [dbo].[fact] as [$Outer]     left outer join     (         select [_].[BU_Key] as [BU_Key],             [_].[BU_Code] as [BU_Code2],             [_].[BU_Name] as [BU_Name],             [_].[StartDate] as [StartDate],             [_].[EndDate] as [EndDate]         from [dbo].[BU] as [_]     ) as [$Inner] on ([$Outer].[BU_Code] = [$Inner].[BU_Code2] or [$Outer].[BU_Code] is null and [$Inner].[BU_Code2] is null) ) as [_] where [_].[Date] >= [_].[StartDate] and [_].[Date] <= [_].[EndDate] The resulting query is a little strange, you can probably tell that it was generated programmatically. But if you look closely you'll notice that every single part of the Power Query formula has been pushed down to SQL Server. Power Query itself ends up just constructing the query and passing the results back to Excel, it does not do any of the data transformation steps itself. So now you can feel a bit more comfortable showing Power Query to your less technical Colleagues knowing that the tool will do it's best fold all the  small steps in Power Query down the most efficient query that it can against the source systems.

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• Is anyone doing "real" TDD with Visual-C++, and if yes, how do they do it?

  - by Martin

  Test Driven Development implies writing the test before the code and following a certain cycle: Write Test Check Test (run) Write Production Code Check Test (run) Clean up Production Code Check test (run) As far as I'm concerned, this is only possible if your development solution allows you to very quickly switch between the production and test code, and to execute the test for a certain production code part extremely quickly. Now, while there exist lots of Unit Testing Frameworks for C++ (I'm using Bost.Test atm.) it does seem that there doesn't really exist any decent (for native C++) Visual Studio (Plugin) solution that makes the TDD cycle bearable regardless of framework used. "Bearable" means that it's a one-click action to run a test for a certain cpp file without having to manually set up a separate testing project etc. "Bearable" also means that a simple test starts (linking!) and runs very quickly. So, what tools (plugins) and techniques are out there that make the TDD cycle possible for native C++ development with Visual Studio? Note: I'm fine with free or "commercial" tools. Please: No framework recommendations. (Unless the framework has a dedicated Visual Studio plugin and you want to recommend the plugin.) Edit Note: The answers so far have provided links on how to integrate a Unit Testing framework into Visual Studio. The resources more or less describe how to get the UT framework to compile and get your first Tests running. This is not what this question is about. I'm of the opinion that to really work productively, having the Unit Tests in a manually maintained(!), separate vcproj from your production classes will add so much overhead that TDD "isn't possible". As far as I am aware, you do not add extra "projects" to a Java or C# thing to enable Unit Tests and TDD, and for a good reason. This should be possible with C++ given the right tools, but it seems (this question is about) that there are very little tools for TDD/C++/VS. Googling around, I've found one tool, VisualAssert, that seems to aim in the right direction. However, afaiks, it doesn't seem to be in widespread use (compared to CppUnit, Boost.Test etc.). Edit: I would like to add a comment to the context for this question. I think it does a good summary of outlining (part of) the problem: (comment by Billy ONeal) Visual Studio does not use "build scripts" that are reasonably editable by the user. One project produces one binary. Moreover, Java has the property that Java never builds a complete binary -- the binary you build is just a ZIP of the class files. Therefore it's possible to compile separately then JAR together manually (using e.g. 7z). C++ and C# both actually link their binaries, so generally speaking you can't write a script like that. The closest you can get is to compile everything separately and then do two linkings (one for production, one for testing).

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• Effectiveness and Efficiency

  - by Daniel Moth

  In the professional environment, i.e. at work, I am always seeking personal growth and to be challenged. The result is that my assignments, my work list, my tasks, my goals, my commitments, my [insert whatever word resonates with you] keep growing (in scope and desired impact). Which in turn means I have to keep finding new ways to deliver more value, while not falling into the trap of working more hours. To do that I continuously evaluate both my effectiveness and my efficiency. EFFECTIVENESS The first thing I check is my effectiveness: Am I doing the right things? Am I focusing too much on unimportant things? Am I spending more time doing stuff that is important to my team/org/division/business/company, or am I spending it on stuff that is important to me and that I enjoy doing? Am I valuing activities that maybe I have outgrown and should be delegated to others who are at a stage I have surpassed (in Microsoft speak: is the work I am doing level appropriate or am I still operating at the previous level)? Notice how the answers to those questions change over time and due to certain events, so I have to remind myself to revisit them frequently. Events that force me to re-examine them are: change of role, change of team/org/etc, change of direction of team/org/etc, re-org, new hires on the team that take on some of the work I did, personal promotion, change of manager... and if none of those events has occurred since the last annual review, I ask myself those at each annual review anyway. If you think you are not being effective at work, make a list of the stuff that you do and start tracking where your time goes. In parallel, have a discussion with your manager about where they think your time should go. Ultimately your time is finite and hence it is your most precious investment, don't waste it. If your management doesn't value as highly what you spend your time on, then either convince your management, or stop spending your time on it, or find different management: Lead, Follow, or get out of the way! That's my view on effectiveness. You have to fix that before moving to being efficient, or you may end up being very efficient at stuff that nobody wants you to be doing in the first place. For example, you may be spending your time writing blog posts and becoming better and faster at it all the time. If your manager thinks that is not even part of your job description, you are wasting your time to satisfy your inner desires. Nobody can help you with your effectiveness other than your management chain and your management peers - they are the judges of it. EFFICIENCY The second thing I check is my efficiency: Am I doing things right? For me, doing things right means that I deliver the same quality of work faster [than what I used to, and than my peers, and than expected of me]. The result is that I can achieve more [than what I used to, and than my peers, and than expected of me]. Notice how the efficiency goal is a more portable one. If, by whatever criteria, you think you are the best at [insert your own skill here], this can change at two events: because you have new colleagues (who are potentially better than your older ones), and it can change with a change of manager (who has potentially higher expectations). That's about it. Once you are efficient at something, you carry that with you... All you need to really be doing here is, when taking on new kinds of work that you haven't done before, try a few approaches and devise a system so that you can become efficient at this new activity too... Just keep "collecting" stuff that you are efficient at. If you think you are not being efficient at something, break it down: What are the steps you take to complete that task? How long do you spend on each step? Talk to others about what steps they take, to see if you can optimize some steps away or trade them for better steps, or just learn how to complete a step faster. Have a system for every task you take so that you can have repeatable success. That's my view on efficiency. You have to fix it so that you can free up time to do more. When you plan a route from A to B - all else being equal - you try to get there as fast as possible so why would you not want to do that with your everyday work? For example, imagine you are inefficient at processing email: You spend more time than necessary dealing with email, and you still end up with dropped email threads and with slower response times than others. How can you improve? Talk to someone that you think is good at this, understand their system (e.g. here is my email processing system) and come up with one that works for you. Parting Thoughts Are you considered, by your colleagues and manager, an effective and efficient person at your workplace? If you are, what would you change if you were asked by your management to do the job of two people? Seriously, think about that! Your immediate reaction may be "that is not possible", but it actually is. You just have to re-assess what things that were previously important will now stop being important, by discussing them with your management and reaching agreement on relative priorities. For example, stuff that was previously on your plate may now have to be delegated or dropped. Where you thought you were efficient, maybe now you have to find an even faster path to completion, perhaps keeping in mind that Perfect is the Enemy of “Good Enough”. My personal experience (from both observing others and from my own reflection) is that when folks are struggling to keep up at work it is because of two reasons: They are investing energy in stuff that they enjoy doing which the business regards as having a lower priority than a lot of other things on their plate. They are completing tasks to a level of higher quality than what is required (due to personal pride) missing the big picture which almost always mandates completing three tasks at good enough quality than knocking only one of them out of the park while the other two come in late or not at all. There is a lot of content on the web, so I strongly encourage you to use your favorite search engine to read other views on effectiveness and efficiency (Bing, Google). Comments about this post by Daniel Moth welcome at the original blog.

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• My Automated NuGet Workflow

  - by Wes McClure

  When we develop libraries (whether internal or public), it helps to have a rapid ability to make changes and test them in a consuming application. Building Setup the library with automatic versioning and a nuspec Setup library assembly version to auto increment build and revision AssemblyInfo –> [assembly: AssemblyVersion("1.0.*")] This autoincrements build and revision based on time of build Major & Minor Major should be changed when you have breaking changes Minor should be changed once you have a solid new release During development I don’t increment these Create a nuspec, version this with the code nuspec - set version to <version>$version$</version> This uses the assembly’s version, which is auto-incrementing Make changes to code Run automated build (ruby/rake) run “rake nuget” nuget task builds nuget package and copies it to a local nuget feed I use an environment variable to point at this so I can change it on a machine level! The nuget command below assumes a nuspec is checked in called Library.nuspec next to the csproj file $projectSolution = 'src\\Library.sln' $nugetFeedPath = ENV["NuGetDevFeed"] msbuild :build => [:clean] do |msb| msb.properties :configuration => :Release msb.targets :Build msb.solution = $projectSolution end task :nuget => [:build] do sh "nuget pack src\\Library\\Library.csproj /OutputDirectory " + $nugetFeedPath end Setup the local nuget feed as a nuget package source (this is only required once per machine) Go to the consuming project Update the package Update-Package Library or Install-Package TLDR change library code run “rake nuget” run “Update-Package library” in the consuming application build/test! If you manually execute any of this process, especially copying files, you will find it a burden to develop the library and will find yourself dreading it, and even worse, making changes downstream instead of updating the shared library for everyone’s sake. Publishing Once you have a set of changes that you want to release, consider versioning and possibly increment the minor version if needed. Pick the package out of your local feed, and copy it to a public / shared feed! I have a script to do this where I can drop the package on a batch file Replace apikey with your nuget feed's apikey Take out the confirm(s) if you don't want them @ECHO off echo Upload %1? set /P anykey="Hit enter to continue " nuget push %1 apikey set /P anykey="Done " Note: helps to prune all the unnecessary versions during testing from your local feed once you are done and ready to publish TLDR consider version number run command to copy to public feed

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• Simplifying Human Capital Management with Mobile Applications

  - by HCM-Oracle

  By Aaron Green If you're starting to think 'mobility' is a recurring theme in your reading, you'd be right. For those who haven't started to build organisational capabilities to leverage it, it's fair to say you're late to the party. The good news: better late than never. Research firm eMarketer says the worldwide smartphone audience will total 1.75 billion this year, while communications technology and services provider Ericsson suggests smartphones will triple to 5.6 billion globally by 2019. It should be no surprise, smart phone adoption is reaching the farthest corners of the globe; the subsequent impact of enterprise applications enabled by these devices is driving business performance improvement and will continue to do so. Companies using advanced workforce analytics can add significantly to the bottom line, while impacting customer satisfaction, quality and productivity. It's a statement that makes most business leaders sit forward in their chairs. Achieving these three standards is like sipping The Golden Elixir for the business world. No-one would argue their importance. So what are 'advanced workforce analytics?' Simply, they're unprecedented access to workforce trends and performance markers. Many are made possible by a mobile world and the enterprise applications that come with it on smart devices. Some refer to it as 'the consumerisation of IT'. As this phenomenon has matured and become more widely appreciated it has impacted the spectrum of functional units within an enterprise differently, but powerfully. Whether it's sales, HR, marketing, IT, or operations, all have benefited from a more mobile approach. It has been the catalyst for improvement in, and management of, the employee experience. The net result of which is happier customers. The obvious benefits but the lesser realised impact Most people understand that mobility allows for greater efficiency and productivity, collaboration and flexibility, but how that translates into business outcomes within the various functional groups is lesser known. In actuality mobility has helped galvanise partnerships between cross-functional groups within the enterprise. Where in some quarters it was once feared mobility could fragment a workforce, its rallying cry of support is coming from what you might describe as an unlikely source - HR. As the bedrock of an enterprise, it is conceivable HR might contemplate the possible negative impact of a mobile workforce that no-longer sits in an office, at the same desks every day. After all, who would know what they were doing or saying? How would they collaborate? It's reasonable to see why HR might have a legitimate claim to try and retain as much 'perceived control' as possible. The reality however is mobility has emancipated human capital and its management. Mobility and enterprise applications are expediting decision making. Google calls it Zero Moment of Truth, or ZMOT. It enables smoother operation and can contribute to faster growth. From a collaborative perspective, with the growing use of enterprise social media, which in many cases is being driven by HR, workforce planning and the tangible impact of change is much easier to map. This in turn provides a platform from which individuals and teams can thrive. With more agility and ability to anticipate, staff satisfaction and retention is higher, and real time feedback constant. The management team can save time, energy and costs with more accurate data, which is then intelligently applied across the workforce to truly engage with staff, customers and partners. From a human capital management (HCM) perspective, mobility can help you close the loop on true talent management. It can enhance what managers can offer and what employees can provide in return. It can create nested relationships and powerful partnerships. IT and HR - partners and stewards of mobility One effect of enterprise mobility is an evolution in the nature of the relationship between HR and IT from one of service provision to partnership. The reason for the dynamic shift is largely due to the 'bring your own device' (BYOD) movement, which is transitioning to a 'bring your own application' (BYOA) scenario. As enterprise technology has in some ways reverse-engineered its solutions to help manage this situation, the partnership between IT (the functional owner) and HR (the strategic enabler) is deeply entrenched. And it has to be. The CIO and the HR leader are faced with compliance and regulatory issues and concerns around information security and personal privacy on a daily basis, complicated by global reach and varied domestic legislation. There are tens of thousands of new mobile apps entering the market each month and, unlike many consumer applications which get downloaded but are often never opened again after initial perusal, enterprise applications are being relied upon by functional groups, not least by HR to enhance people management. It requires a systematic approach across all applications in use within the enterprise in order to ensure they're used to best effect. No turning back, and no desire to With real time analytics on performance and the ability for immediate feedback, there is no turning back for managers. In my experience with Oracle, our customers' operational efficiency is at record levels. It's clear as a result of the combination of individual KPIs and organisational goals, CIOs have been able to give HR leaders the ability to build predictive models that feed into an enterprise organisations' evolving strategy. It also helps them ensure regulatory compliance much more easily. Once an arduous task, with mobile enabled automation and quality data, compliance is simpler. Their world has changed for the better. For the CIO, mobility also assists them to optimise performance. While it doesn't come without challenges, mobile-enabled applications and the native experience users have with them means employees don't need high-level technical expertise to train users. It reduces the training and engagement required from the IT team so they can focus on other things that deliver value to the bottom line; all the while lowering the cost of assets and related maintenance work by simplifying processes. Rewards of a mobile enterprise outweigh risks With mobile tools allowing us to increasingly integrate our personal and professional lives, terms like "office hours" are becoming irrelevant, so work/life balance is a cultural must. Enterprises are expected to offer tools that enable workers to access information from anywhere, at any time, from any device. Employees want simplicity and convenience but it doesn't stop at private enterprise. This is a societal shift. Governments, which traditionally have been known to be slower to adopt newer technology, are also offering support for local businesses to go mobile. Several state government websites have advice on how to create mobile apps and more. And as recently as last week the Victorian Minister for Technology Gordon Rich-Phillips unveiled his State government's ICT roadmap for the next two years, which details an increased use of the public cloud, as well as mobile communications, and improved access to online data-sets. Tech giants are investing significantly in solutions designed to simplify mobile deployment and enablement. The mobility trend is creating a wave of change in the industry and driving transformation in the enterprise. If you're not on that wave, the business risk continues to rise as your competitiveness drops. Aaron is the Vice President of HCM Strategy at Oracle Corporation where he is responsible for researching and identifying emerging trends in the practice of Human Resources and works to deliver industry-leading technology solutions. Other responsibilities include, ownership of Oracle's innovative HCM solutions across JAPAC and enabling organisations to transform and modernise their workforce tools. Follow him on Twitter @aaronjgreen

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• Convert VARCHAR() columns to NVARCHAR()

  - by ChrisD

  We recently underwent an upgrade that required us to change our database columns from varchar to NVarchar, to support unicode characters. Digging through the internet, I found a base script which I modified to handle reserved word table names, and maintain the NULL/NotNull constraint of the columns.   I Ran this script use NWOperationalContent – Your Catalog Name here GO SELECT 'ALTER TABLE ' + isnull(schema_name(syo.id), 'dbo') + '.[' +  syo.name +'] '     + ' ALTER COLUMN [' + syc.name + '] NVARCHAR(' + case syc.length when -1 then 'MAX'         ELSE convert(nvarchar(10),syc.length) end + ') '+         case  syc.isnullable when 1 then ' NULL' ELSE ' NOT NULL' END +';'    FROM sysobjects syo    JOIN syscolumns syc ON      syc.id = syo.id    JOIN systypes syt ON      syt.xtype = syc.xtype    WHERE      syt.name = 'varchar'     and syo.xtype='U'   which produced a series of ALTER statements which I could then execute the tables.  In some cases I had to drop indexes, alter the tables, and re-create the indexes.  There might have been a better way to do that, but manually dropping them got the job done.   use NWMerchandisingContent GO ALTER TABLE Locale Drop Constraint PK_Locale ALTER TABLE Country DROP CONSTRAINT PK_Country GO ALTER TABLE dbo.[Campaign]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[BundleLocalization]  ALTER COLUMN [Locale] NVARCHAR(8)  NOT NULL; ALTER TABLE dbo.[BundleLocalization]  ALTER COLUMN [UnitOfmeasure] NVARCHAR(200)  NULL; ALTER TABLE dbo.[BundleLocalization]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[BundleComponentLocalization]  ALTER COLUMN [Locale] NVARCHAR(8)  NOT NULL; ALTER TABLE dbo.[BundleComponentLocalization]  ALTER COLUMN [Imperative] NVARCHAR(MAX)  NULL; ALTER TABLE dbo.[BundleComponentLocalization]  ALTER COLUMN [Instructions] NVARCHAR(MAX)  NULL; ALTER TABLE dbo.[BundleComponentLocalization]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[BundleComponent]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[Bundle]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[Banner]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[Video]  ALTER COLUMN [Link] NVARCHAR(512)  NOT NULL; ALTER TABLE dbo.[Video]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[ProductUsage]  ALTER COLUMN [VideoLink] NVARCHAR(512)  NOT NULL; ALTER TABLE dbo.[ProductUsage]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[Thumbnail]  ALTER COLUMN [ActorKey] NVARCHAR(200)  NOT NULL; ALTER TABLE dbo.[SkuLocalization]  ALTER COLUMN [Locale] NVARCHAR(8)  NOT NULL; ALTER TABLE dbo.[SkuLocalization]  ALTER COLUMN [UnitOfMeasure] NVARCHAR(150)  NOT NULL; ALTER TABLE dbo.[SkuLocalization]  ALTER COLUMN [SwatchColor] NVARCHAR(50)  NOT NULL; etc.. GO ALTER TABLE Locale ADD CONSTRAINT PK_Locale PRIMARY KEY (LocaleId) ALTER TABLE Country ADD CONSTRAINT PK_Country PRIMARY KEY (CountryId) Note that this alter is non-destructive to the data.   Hope this helps.

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• Saddling your mountain lion with JDeveloper

  - by Blueberry Coder

  Last October, Apple released Java Update 2012-006. This patch brought the Apple-provided JDK for OS X Lion v10.7 and OS X Mountain Lion v10.8 to version 1.6.0_37. At the same time, it disabled the Apple Java plugins and removed the Java Preferences panel that enabled users to manage the various Java releases on their computer. On the Windows and Linux platforms, JDeveloper 11g R1 has been certified  to run on Java 7 since patch set 5. This is not the case on OS X.   ( The above is not a typo. Apple's OS for personal computer is now known as OS X; the « Mac » prefix has been dropped with the 10.8 release. And it's pronounced « Oh-Ess-Ten », by the way. Yes, I am a nitpicker. I know... ) Please note JDeveloper 11g R2 is not certified either. On any platform. It will generally work, but there are known issues with ADF Mobile. Personally, I would recommend to wait for 12c before going to JDK 7.  Now, suppose you have installed Oracle's JDK 7 on your Mac. JDeveloper will not run on it. It will even not install. Susan and I discovered this the hard way while setting up the ADF Mobile hands-on lab we ran at the UKOUG 2012 conference. The lab was a great success nevertheless, attracting nearly a hundred delegates. It was great to see the interest ADF Mobile already generates, especially among PL/SQL Developers and DBAs. But what did we do to make it work?  While Java Update 2012-006 removed the Java Preferences panel, it leaved in place OS X's command-line Java infrastructure. Thus, it is possible to invoke the Apple JDK 6 to start the JDeveloper installer. Suppose your user is named « Fred », and that the JDeveloper installer is on your desktop. You can execute the following command in a terminal window (on a single line) to start the installer:  /usr/libexec/java_home --version 1.6.0  --exec java -jar /Users/Fred/Desktop/jdevstudio11116install.jar  The JDeveloper installer, being provided a valid JDK reference, will set up the IDE and embedded WebLogic Server instance accordingly. Clever engineering at its finest!

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• How to properly do weapon cool-down reload timer in multi-player laggy environment?

  - by John Murdoch

  I want to handle weapon cool-down timers in a fair and predictable way on both client on server. Situation: Multiple clients connected to server, which is doing hit detection / physics Clients have different latency for their connections to server ranging from 50ms to 500ms. They want to shoot weapons with fairly long reload/cool-down times (assume exactly 10 seconds) It is important that they get to shoot these weapons close to the cool-down time, as if some clients manage to shoot sooner than others (either because they are "early" or the others are "late") they gain a significant advantage. I need to show time remaining for reload on player's screen Clients can have clocks which are flat-out wrong (bad timezones, etc.) What I'm currently doing to deal with latency: Client collects server side state in a history, tagged with server timestamps Client assesses his time difference with server time: behindServerTimeNs = (behindServerTimeNs + (System.nanoTime() - receivedState.getServerTimeNs())) / 2 Client renders all state received from server 200 ms behind from his current time, adjusted by what he believes his time difference with server time is (whether due to wrong clocks, or lag). If he has server states on both sides of that calculated time, he (mostly LERP) interpolates between them, if not then he (LERP) extrapolates. No other client-side prediction of movement, e.g., to make his vehicle seem more responsive is done so far, but maybe will be added later So how do I properly add weapon reload timers? My first idea would be for the server to send each player the time when his reload will be done with each world state update, the client then adjusts it for the clock difference and thus can estimate when the reload will be finished in client-time (perhaps considering also for latency that the shoot message from client to server will take as well?), and if the user mashes the "shoot" button after (or perhaps even slightly before?) that time, send the shoot event. The server would get the shoot event and consider the time shot was made as the server time when it was received. It would then discard it if it is nowhere near reload time, execute it immediately if it is past reload time, and hold it for a few physics cycles until reload is done in case if it was received a bit early. It does all seem a bit convoluted, and I'm wondering whether it will work (e.g., whether it won't be the case that players with lower ping get better reload rates), and whether there are more elegant solutions to this problem.

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