Search Results

Search found 15081 results on 604 pages for 'passing by reference'.

Page 163/604 | < Previous Page | 159 160 161 162 163 164 165 166 167 168 169 170  | Next Page >

  • SQL SERVER – Identify Numbers of Non Clustered Index on Tables for Entire Database

    - by pinaldave
    Here is the script which will give you numbers of non clustered indexes on any table in entire database. SELECT COUNT(i.TYPE) NoOfIndex, [schema_name] = s.name, table_name = o.name FROM sys.indexes i INNER JOIN sys.objects o ON i.[object_id] = o.[object_id] INNER JOIN sys.schemas s ON o.[schema_id] = s.[schema_id] WHERE o.TYPE IN ('U') AND i.TYPE = 2 GROUP BY s.name, o.name ORDER BY schema_name, table_name Here is the small story behind why this script was needed. I recently went to meet my friend in his office and he introduced me to his colleague in office as someone who is an expert in SQL Server Indexing. I politely said I am yet learning about Indexing and have a long way to go. My friend’s colleague right away said – he had a suggestion for me with related to Index. According to him he was looking for a script which will count all the non clustered on all the tables in the database and he was not able to find that on SQLAuthority.com. I was a bit surprised as I really do not remember all the details about what I have written so far. I quickly pull up my phone and tried to look for the script on my custom search engine and he was correct. I never wrote a script which will count all the non clustered indexes on tables in the whole database. Excessive indexing is not recommended in general. If you have too many indexes it will definitely negatively affect your performance. The above query will quickly give you details of numbers of indexes on tables on your entire database. You can quickly glance and use the numbers as reference. Please note that the number of the index is not a indication of bad indexes. There is a lot of wisdom I can write here but that is not the scope of this blog post. There are many different rules with Indexes and many different scenarios. For example – a table which is heap (no clustered index) is often not recommended on OLTP workload (here is the blog post to identify them), drop unused indexes with careful observation (here is the script for it), identify missing indexes and after careful testing add them (here is the script for it). Even though I have given few links here it is just the tip of the iceberg. If you follow only above four advices your ship may still sink. Those who wants to learn the subject in depth can watch the videos here after logging in. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Continue with out a default route?

    - by user2009
    I am doing a complete unattended install of Ubuntu 12.04. I am doing static network configuration. Here is content for Static network configuration from the preseed file. d-i netcfg/disable_dhcp boolean true d-i netcfg/no_default_route boolean true d-i netcfg/get_nameservers string 192.168.1.254 d-i netcfg/get_ipaddress string 192.168.1.13 d-i netcfg/get_netmask string 255.255.255.0 d-i netcfg/get_gateway string 192.168.1.1 d-i netcfg/confirm_static boolean true Still is asking "Continue without a default route?". I have to say , then only installed is going ahead. Am passing preseed file via network (preseed/url). How to avoid this manual intervention? Does the order of netcfg statements matter?

    Read the article

  • SQL SERVER – Weekly Series – Memory Lane – #035

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Row Overflow Data Explanation  In SQL Server 2005 one table row can contain more than one varchar(8000) fields. One more thing, the exclusions has exclusions also the limit of each individual column max width of 8000 bytes does not apply to varchar(max), nvarchar(max), varbinary(max), text, image or xml data type columns. Comparison Index Fragmentation, Index De-Fragmentation, Index Rebuild – SQL SERVER 2000 and SQL SERVER 2005 An old but like a gold article. Talks about lots of concepts related to Index and the difference from earlier version to the newer version. I strongly suggest that everyone should read this article just to understand how SQL Server has moved forward with the technology. Improvements in TempDB SQL Server 2005 had come up with quite a lots of improvements and this blog post describes them and explains the same. If you ask me what is my the most favorite article from early career. I must point out to this article as when I wrote this one I personally have learned a lot of new things. Recompile All The Stored Procedure on Specific TableI prefer to recompile all the stored procedure on the table, which has faced mass insert or update. sp_recompiles marks stored procedures to recompile when they execute next time. This blog post explains the same with the help of a script.  2008 SQLAuthority Download – SQL Server Cheatsheet You can download and print this cheat sheet and use it for your personal reference. If you have any suggestions, please let me know and I will see if I can update this SQL Server cheat sheet. Difference Between DBMS and RDBMS What is the difference between DBMS and RDBMS? DBMS – Data Base Management System RDBMS – Relational Data Base Management System or Relational DBMS High Availability – Hot Add Memory Hot Add CPU and Hot Add Memory are extremely interesting features of the SQL Server, however, personally I have not witness them heavily used. These features also have few restriction as well. I blogged about them in detail. 2009 Delete Duplicate Rows I have demonstrated in this blog post how one can identify and delete duplicate rows. Interesting Observation of Logon Trigger On All Servers – Solution The question I put forth in my previous article was – In single login why the trigger fires multiple times; it should be fired only once. I received numerous answers in thread as well as in my MVP private news group. Now, let us discuss the answer for the same. The answer is – It happens because multiple SQL Server services are running as well as intellisense is turned on. Blog post demonstrates how we can do the same with the help of SQL scripts. Management Studio New Features I have selected my favorite 5 features and blogged about it. IntelliSense for Query Editing Multi Server Query Query Editor Regions Object Explorer Enhancements Activity Monitors Maximum Number of Index per Table One of the questions I asked in my user group was – What is the maximum number of Index per table? I received lots of answers to this question but only two answers are correct. Let us now take a look at them in this blog post. 2010 Default Statistics on Column – Automatic Statistics on Column The truth is, Statistics can be in a table even though there is no Index in it. If you have the auto- create and/or auto-update Statistics feature turned on for SQL Server database, Statistics will be automatically created on the Column based on a few conditions. Please read my previously posted article, SQL SERVER – When are Statistics Updated – What triggers Statistics to Update, for the specific conditions when Statistics is updated. 2011 T-SQL Scripts to Find Maximum between Two Numbers In this blog post there are two different scripts listed which demonstrates way to find the maximum number between two numbers. I need your help, which one of the script do you think is the most accurate way to find maximum number? Find Details for Statistics of Whole Database – DMV – T-SQL Script I was recently asked is there a single script which can provide all the necessary details about statistics for any database. This question made me write following script. I was initially planning to use sp_helpstats command but I remembered that this is marked to be deprecated in future. 2012 Introduction to Function SIGN SIGN Function is very fundamental function. It will return the value 1, -1 or 0. If your value is negative it will return you negative -1 and if it is positive it will return you positive +1. Let us start with a simple small example. Template Browser – A Very Important and Useful Feature of SSMS Templates are like a quick cheat sheet or quick reference. Templates are available to create objects like databases, tables, views, indexes, stored procedures, triggers, statistics, and functions. Templates are also available for Analysis Services as well. The template scripts contain parameters to help you customize the code. You can Replace Template Parameters dialog box to insert values into the script. An invalid floating point operation occurred If you run any of the above functions they will give you an error related to invalid floating point. Honestly there is no workaround except passing the function appropriate values. SQRT of a negative number will give you result in real numbers which is not supported at this point of time as well LOG of a negative number is not possible (because logarithm is the inverse function of an exponential function and the exponential function is NEVER negative). Validating Spatial Object with IsValidDetailed Function SQL Server 2012 has introduced the new function IsValidDetailed(). This function has made my life very easy. In simple words, this function will check if the spatial object passed is valid or not. If it is valid it will give information that it is valid. If the spatial object is not valid it will return the answer that it is not valid and the reason for the same. This makes it very easy to debug the issue and make the necessary correction. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • SQLAuthority News – New Book Released – SQL Server Interview Questions And Answers

    - by pinaldave
    Two days ago, on birthday of my blog – I asked simple question – Guess! What is in this box? I have received lots of interesting comments on the blog about what is in it. Many of you got it absolutely incorrect and many got it close to the right answer but no one got it 100% correct. Well, no issue at all, I am going to give away the price to whoever has the closest answer first in personal email. Here is the answer to the question about what is in the box? Here it is – the box has my new book. In fact, I should say our new book as I co-authored this book with my very good friend Vinod Kumar. We had real blast writing this book together and had lots of interesting conversation when we were writing this book. This book has one simple goal – “master the basics.” This book is not only for people who are preparing for interview. This book is for every one who wants to revisit the basics and wants to prepare themselves to the technology. One always needs to have practical knowledge to do their duty efficiently. This book talks about more than basics. There are multiple ways to present learning – either we can create simple book or make it interesting. We have decided the learning should be interactive and have opted for Interview Questions and Answer format. Here is quick interview which we have done together. Details of the books are here The core concept of this book will continue to evolve over time. I am sure many of you will come along with us on this journey and submit your suggestions to us to make this book a key reference for anybody who wants to start with SQL server. Today we want to acknowledge the fact that you will help us keep this book alive forever with the latest updates. We want to thank everyone who participates in this journey with us. You can get the books from [Amazon] | [Flipkart]. Read Vinod‘s blog post. Do not forget to wish him happy birthday as today is his birthday and also book release day – two reason to wish him congratulations. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Data Warehousing, Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL Interview Questions and Answers, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Book Review, SQLAuthority News, SQLServer, T SQL, Technology

    Read the article

  • Évènement : eMetrics Marketing Optimization Summit, le salon de l'optimisation marketing et de la Bu

    eMetrics Marketing Optimization / SMX - l'événement webmarketing à ne pas manquer La première en France et ce sera au Hilton à Paris le 15 et 16 juin Le sommet eMetrics Marketing Optimization - l´évènement international de référence pour l´e-marketing et le « Web Analytics » - fera son entrée en France, pour la première fois le 15 et 16 juin 2010 à Paris. Depuis 2002, c´est la plateforme de rencontre des responsables marketing, des analystes web et des experts en business intelligence qui souhaitent augmenter leur retour sur investissements en ligne. Il est généralement mené en parallèle avec

    Read the article

  • Silverlight Cream for June 10, 2010 -- #879

    - by Dave Campbell
    In this Issue: Emiel Jongerius, Nokola, Christian Schormann, Tim Heuer, David Poll, Mike Snow(-2-), John Papa, and Charles Petzold. Shoutout: Viktor Larsson has a frank look at WP7 based on information from MIX10 and what was said this week in his post: Licking Windows Phone 7... yeah licking, not liking :) .. my guess is even that didn't allow him to keep it! If you haven't already noticed, the CodeProject reader's choice awards are out this week and Telerik won for their RadColorPicker and RadCalendar for Silverlight Telerik also needs congratulations for winning Telerik wins “Best of TechEd” award in the “Components and Middleware” category... check out that trophy... Steven Forte has a picture up of the Telerikers after getting the award. Koen Zwikstra has a new release of Silverlight Spy up that supports the latest release: Silverlight Spy 3.0.0.12 From SilverlightCream.com: Localization of XAML files in Silverlight Emiel Jongerius is back with another post, this time discussing Localizing XAM files... external links and source included. Coolest Silverlight Sound Library for Games I've Seen Yet Nokola talks up a Sound Library for Silverlight 4 Games ... and has links to a great demo, plus the source. SketchFlow: Firing Actions when a Storyboard is Complete Christian Schormann responded to some Twitter questions and demonstrates using the StoryboardCompleted trigger with a Navigate action. Hosting cross-domain Silverlight applications (XAP) Tim Heuer responds to a question from a reader and demonstrates how to host a XAP from a domain other than the one you're working on. Taking Microsoft Silverlight 4 Applications Beyond the Browser (TechEd WEB313) David Poll has all his material up from his TechEd presentation earlier this week on Silverlight OOB... and he covered some pretty extensive material ... check it out! Silverlight Tip of the Day #29 – Configuring Service Reference to Back to LocalHost Mike Snow has a couple new tips up... this first one is quick, but very useful... how to switch your service reference back to localhost without pulling out your hair. Silverlight Tip of the Day #30 – Sending Email from Silverlight In Mike Snow's latest tip, he shows how to send email from your Silverlight app... using a WCF service... and a step-by-step set of instructions. Creating Rich Interactions Using Blend 4: Transition Effects, Fluid Layout and Layout States (Silverlight TV #32) John Papa has Silverlight TV #32 up, and he's talking with Kenny Young of the Expression Blend team while Kenny uses some built-om effects and also creates some impressive examples from scratch -- code included. Simulating Touch Inertia on Windows Phone 7 Charles Petzold has a post up on simulating inertia on WP7... demos in WPF and then moves into WP7... math, source, and external links. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • Download PowerCommands for VS 2008

    - by Editor
    PowerCommands is a set of useful extensions for the Visual Studio 2008 adding additional functionality to various areas of the IDE. The source code is included and requires the VS SDK for VS 2008 to allow modification of functionality or as a reference to create additional custom PowerCommand extensions. Visit the [...]

    Read the article

  • Geometry instancing in OpenGL ES 2.0

    - by seahorse
    I am planning to do geometry instancing in OpenGL ES 2.0 Basically I plan to render the same geometry(a chair) maybe 1000 times in my scene. What is the best way to do this in OpenGL ES 2.0? I am considering passing model view mat4 as an attribute. Since attributes are per vertex data do I need to pass this same mat4, three times for each vertex of the same triangle(since modelview remains constant across vertices of the triangle). That would amount to a lot of extra data sent to the GPU( 2 extra vertices*16 floats*(Number of triangles) amount of extra data). Or should I be sending the mat4 only once per triangle?But how is that possible using attributes since attributes are defined as "per vertex" data? What is the best and efficient way to do instancing in OpenGL ES 2.0?

    Read the article

  • Flashing screen during videos and games

    - by Collif
    I recently switched from Vista to Ubuntu 12.10 on my HP laptop and I've been having issues with my graphics. Everything is fine till I watch a video/play a game or (sometimes) when I visit the software centre. At that point large portions of the screen start flashing and everything gets rather slow. I'm looking for a way to remedy this. For reference I'm using Firefox and I'm unsure what my video card is because it's listed as unknown when I check my system settings.

    Read the article

  • Learning Resources for SharePoint

    - by Enrique Lima
    SharePoint 2010 Reference: Software Development Kit SharePoint 2010: Getting Started with Development on SharePoint 2010 Hands-on Labs in C# and Visual Basic SharePoint Developer Training Kit Professional Development Evaluation Guide and Walkthrough SharePoint Server 2010: Advanced Developer Training Presentations

    Read the article

  • IntelliSense for Razor Hosting in non-Web Applications

    - by Rick Strahl
    When I posted my Razor Hosting article a couple of weeks ago I got a number of questions on how to get IntelliSense to work inside of Visual Studio while editing your templates. The answer to this question is mainly dependent on how Visual Studio recognizes assemblies, so a little background is required. If you open a template just on its own as a standalone file by clicking on it say in Explorer, Visual Studio will open up with the template in the editor, but you won’t get any IntelliSense on any of your related assemblies that you might be using by default. It’ll give Intellisense on base System namespace, but not on your imported assembly types. This makes sense: Visual Studio has no idea what the assembly associations for the single file are. There are two options available to you to make IntelliSense work for templates: Add the templates as included files to your non-Web project Add a BIN folder to your template’s folder and add all assemblies required there Including Templates in your Host Project By including templates into your Razor hosting project, Visual Studio will pick up the project’s assembly references and make IntelliSense available for any of the custom types in your project and on your templates. To see this work I moved the \Templates folder from the samples from the Debug\Bin folder into the project root and included the templates in the WinForm sample project. Here’s what this looks like in Visual Studio after the templates have been included:   Notice that I take my original example and type cast the Context object to the specific type that it actually represents – namely CustomContext – by using a simple code block: @{ CustomContext Model = Context as CustomContext; } After that assignment my Model local variable is in scope and IntelliSense works as expected. Note that you also will need to add any namespaces with the using command in this case: @using RazorHostingWinForm which has to be defined at the very top of a Razor document. BTW, while you can only pass in a single Context 'parameter’ to the template with the default template I’ve provided realize that you can also assign a complex object to Context. For example you could have a container object that references a variety of other objects which you can then cast to the appropriate types as needed: @{ ContextContainer container = Context as ContextContainer; CustomContext Model = container.Model; CustomDAO DAO = container.DAO; } and so forth. IntelliSense for your Custom Template Notice also that you can get IntelliSense for the top level template by specifying an inherits tag at the top of the document: @inherits RazorHosting.RazorTemplateFolderHost By specifying the above you can then get IntelliSense on your base template’s properties. For example, in my base template there are Request and Response objects. This is very useful especially if you end up creating custom templates that include your custom business objects as you can get effectively see full IntelliSense from the ‘page’ level down. For Html Help Builder for example, I’d have a Help object on the page and assuming I have the references available I can see all the way into that Help object without even having to do anything fancy. Note that the @inherits key is a GREAT and easy way to override the base template you normally specify as the default template. It allows you to create a custom template and as long as it inherits from the base template it’ll work properly. Since the last post I’ve also made some changes in the base template that allow hooking up some simple initialization logic so it gets much more easy to create custom templates and hook up custom objects with an IntializeTemplate() hook function that gets called with the Context and a Configuration object. These objects are objects you can pass in at runtime from your host application and then assign to custom properties on your template. For example the default implementation for RazorTemplateFolderHost does this: public override void InitializeTemplate(object context, object configurationData) { // Pick up configuration data and stuff into Request object RazorFolderHostTemplateConfiguration config = configurationData as RazorFolderHostTemplateConfiguration; this.Request.TemplatePath = config.TemplatePath; this.Request.TemplateRelativePath = config.TemplateRelativePath; // Just use the entire ConfigData as the model, but in theory // configData could contain many objects or values to set on // template properties this.Model = config.ConfigData as TModel; } to set up a strongly typed Model and the Request object. You can do much more complex hookups here of course and create complex base template pages that contain all the objects that you need in your code with strong typing. Adding a Bin folder to your Template’s Root Path Including templates in your host project works if you own the project and you’re the only one modifying the templates. However, if you are distributing the Razor engine as a templating/scripting solution as part of your application or development tool the original project is likely not available and so that approach is not practical. Another option you have is to add a Bin folder and add all the related assemblies into it. You can also add a Web.Config file with assembly references for any GAC’d assembly references that need to be associated with the templates. Between the web.config and bin folder Visual Studio can figure out how to provide IntelliSense. The Bin folder should contain: The RazorHosting.dll Your host project’s EXE or DLL – renamed to .dll if it’s an .exe Any external (bin folder) dependent assemblies Note that you most likely also want a reference to the host project if it contains references that are going to be used in templates. Visual Studio doesn’t recognize an EXE reference so you have to rename the EXE to DLL to make it work. Apparently the binary signature of EXE and DLL files are identical and it just works – learn something new everyday… For GAC assembly references you can add a web.config file to your template root. The Web.config file then should contain any full assembly references to GAC components: <configuration> <system.web> <compilation debug="true"> <assemblies> <add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add assembly="System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> <add assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </assemblies> </compilation> </system.web> </configuration> And with that you should get full IntelliSense. Note that if you add a BIN folder and you also have the templates in your Visual Studio project Visual Studio will complain about reference conflicts as it’s effectively seeing both the project references and the ones in the bin folder. So it’s probably a good idea to use one or the other but not both at the same time :-) Seeing IntelliSense in your Razor templates is a big help for users of your templates. If you’re shipping an application level scripting solution especially it’ll be real useful for your template consumers/users to be able to get some quick help on creating customized templates – after all that’s what templates are all about – easy customization. Making sure that everything is referenced in your bin folder and web.config is a good idea and it’s great to see that Visual Studio (and presumably WebMatrix/Visual Web Developer as well) will be able to pick up your custom IntelliSense in Razor templates.© Rick Strahl, West Wind Technologies, 2005-2011Posted in Razor  

    Read the article

  • Update/Insert With ADF Web Service Data Control

    - by shay.shmeltzer
    The Web service data control (WSDC) in ADF is a powerful feature that allows you to easily build a UI on top of WS interfaces exposed by other systems. However when you drag a WSDC to a page you usually get a set of output components where the data is shown. So how would you actually do an update operation on those values? The answer is that you need a call to another method in your WSDC that does the update - but what if you want to pass to it the actual values that you get from the get method you invoked before? Here is a demo showing how to do that: The two tricks that are shown here are: Changing the properties of items in the DC to be updateable - this gives you inputText fields instead of outputText fields. And passing the currentRow.dataProvider to the update method (and choosing the right iterator for this).

    Read the article

  • Be Careful When Referencing SPList.Items

    - by Brian Jackett
    Be very careful how you reference your SPListItem objects through the SharePoint API.  I’ll say it again.  Be very careful how you reference your SPListItem objects through the SharePoint API.  Ok, now that you get the point that this will be a “learn from my mistakes and don’t do unsmart things like I did” post, let’s dig into what it was that I did poorly. Scenario     For the past year I’ve been building custom .Net applications that are hosted through SharePoint.  These application involve a number of SharePoint lists, external databases, custom web parts, and other SharePoint elements to provide functionality.  About two weeks ago I received a message from one of our end users that a custom application was performing slowly.  Specifically performance was slow when users were performing actions that interacted with the primary SharePoint list storing data for that app. The Problem     I took a copy of the production site into a dev environment to investigate the code that was executing.  After attaching the debugger and running through the code I quickly found pieces of code referencing SPListItem objects (like below) that were performing very poorly: SPListItem myItem = SPContext.Current.Web.Lists["List Name"].Items.GetItemById(value); // do updates on SPListItem retrieved     As it turns out the SPList I was referencing was fairly large at ~1000 items and weighing in over 150 MB.  You see the problem with my above code is that I retrieved the SPListItem by first (unnecessarily) going through the Items member of the list.  As I understand it, when doing so the executing code will attempt to resolve that entity and pull it from the database and into RAM (all 150 MB.)  This causes the equivalent of a 50 car pile up in terms of performance with a single update taking more than 15 seconds. The Solution     The solution is actually quite simple and I wish I had realized this during development.  Instead of going through the Items member it is possible to call GetItemById(…) directly on the SPList as in the example below: SPListItem myItem = SPContext.Current.Web.Lists["List Name"].GetItemById(value); // do updates on SPListItem retrieved     After making this simple change performance skyrocketed and updates were back to less than a second.   Conclusion     When given the option between two solutions, usually the simplest is the best solution.  In my scenario I was adding extra complexity going through the API the long way around to get to the objects I needed and it ended up hurting performance greatly.  Luckily we were able to find and resolve the performance issue in a relatively short amount of time.  Like I said at the beginning of the post, learn from my mistakes and hope it helps you.         -Frog Out   Image linked from http://www.freespirit.com/files/IMAGE/COVER/LARGE/BeCarefulSafe.jpg

    Read the article

  • Online Introduction to Relational Databases (and not only) with Stanford University!

    - by Luca Zavarella
    How many of you know exactly the definition of "relational database"? What exactly the adjective "relational" refers to? Many of you allow themselves to be deceived, thinking this adjective is related to foreign key constraints between tables. Instead this adjective lurks in a world based on set theory, relational algebra and the concept of relationship intended as a table.Well, for those who want to deep the fundamentals of relational model, relational algebra, XML, OLAP and emerging "NoSQL" systems, Stanford University School of Engineering offers a public and free online introductory course to databases. This is the related web page: http://www.db-class.com/ The course will last 2 months, after which there will be a final exam. Passing the final exam will entitle the participants to receive a statement of accomplishment. A syllabus and more information is available here. Happy eLearning to you!

    Read the article

  • How to wire finite state machine into component-based architecture?

    - by Pup
    State machines seem to cause harmful dependencies in component-based architectures. How, specifically, is communication handled between a state machine and the components that carry out state-related behavior? Where I'm at: I'm new to component-based architectures. I'm making a fighting game, although I don't think that should matter. I envision my state machine being used to toggle states like "crouching", "dashing", "blocking", etc. I've found this state-management technique to be the most natural system for a component-based architecture, but it conflicts with techniques I've read about: Dynamic Game Object Component System for Mutable Behavior Characters It suggests that all components activate/deactivate themselves by continually checking a condition for activation. I think that actions like "running" or "walking" make sense as states, which is in disagreement with the accepted response here: finite state machine used in mario like platform game I've found this useful, but ambiguous: How to implement behavior in a component-based game architecture? It suggests having a separate component that contains nothing but a state machine. But, this necessitates some kind of coupling between the state machine component and nearly all the other components. I don't understand how this coupling should be handled. These are some guesses: A. Components depend on state machine: Components receive reference to state machine component's getState(), which returns an enumeration constant. Components update themselves regularly and check this as needed. B. State machine depends on components: The state machine component receives references to all the components it's monitoring. It queries their getState() methods to see where they're at. C. Some abstraction between them Use an event hub? Command pattern? D. Separate state objects that reference components State Pattern is used. Separate state objects are created, which activate/deactivate a set of components. State machine switches between state objects. I'm looking at components as implementations of aspects. They do everything that's needed internally to make that aspect happen. It seems like components should function on their own, without relying on other components. I know some dependencies are necessary, but state machines seem to want to control all of my components.

    Read the article

  • 5 Reasons why I hate WPF

    - by Richard Mitchell
    I decided to use writing a new tool as a way to learn WPF and MVVM and I thought I'd write down a few of my problems as a way of cathartic release. I decided to read a book before attempting WPF for the first time as I've heard others complain about the steep learning curve. I chose the rather excellent "WPF 4 Unleashed" by Adam Nathan to read through and "Pro WPF in C# 2010" by Matthew MacDonald as a reference whilst I programmed. 1 - Poor editing support for XAML The first thing I think any...(read more)

    Read the article

  • How to Achieve OC4J RMI Load Balancing

    - by fip
    This is an old, Oracle SOA and OC4J 10G topic. In fact this is not even a SOA topic per se. Questions of RMI load balancing arise when you developed custom web applications accessing human tasks running off a remote SOA 10G cluster. Having returned from a customer who faced challenges with OC4J RMI load balancing, I felt there is still some confusions in the field how OC4J RMI load balancing work. Hence I decide to dust off an old tech note that I wrote a few years back and share it with the general public. Here is the tech note: Overview A typical use case in Oracle SOA is that you are building web based, custom human tasks UI that will interact with the task services housed in a remote BPEL 10G cluster. Or, in a more generic way, you are just building a web based application in Java that needs to interact with the EJBs in a remote OC4J cluster. In either case, you are talking to an OC4J cluster as RMI client. Then immediately you must ask yourself the following questions: 1. How do I make sure that the web application, as an RMI client, even distribute its load against all the nodes in the remote OC4J cluster? 2. How do I make sure that the web application, as an RMI client, is resilient to the node failures in the remote OC4J cluster, so that in the unlikely case when one of the remote OC4J nodes fail, my web application will continue to function? That is the topic of how to achieve load balancing with OC4J RMI client. Solutions You need to configure and code RMI load balancing in two places: 1. Provider URL can be specified with a comma separated list of URLs, so that the initial lookup will land to one of the available URLs. 2. Choose a proper value for the oracle.j2ee.rmi.loadBalance property, which, along side with the PROVIDER_URL property, is one of the JNDI properties passed to the JNDI lookup.(http://docs.oracle.com/cd/B31017_01/web.1013/b28958/rmi.htm#BABDGFBI) More details below: About the PROVIDER_URL The JNDI property java.name.provider.url's job is, when the client looks up for a new context at the very first time in the client session, to provide a list of RMI context The value of the JNDI property java.name.provider.url goes by the format of a single URL, or a comma separate list of URLs. A single URL. For example: opmn:ormi://host1:6003:oc4j_instance1/appName1 A comma separated list of multiple URLs. For examples:  opmn:ormi://host1:6003:oc4j_instanc1/appName, opmn:ormi://host2:6003:oc4j_instance1/appName, opmn:ormi://host3:6003:oc4j_instance1/appName When the client looks up for a new Context the very first time in the client session, it sends a query against the OPMN referenced by the provider URL. The OPMN host and port specifies the destination of such query, and the OC4J instance name and appName are actually the “where clause” of the query. When the PROVIDER URL reference a single OPMN server Let's consider the case when the provider url only reference a single OPMN server of the destination cluster. In this case, that single OPMN server receives the query and returns a list of the qualified Contexts from all OC4Js within the cluster, even though there is a single OPMN server in the provider URL. A context represent a particular starting point at a particular server for subsequent object lookup. For example, if the URL is opmn:ormi://host1:6003:oc4j_instance1/appName, then, OPMN will return the following contexts: appName on oc4j_instance1 on host1 appName on oc4j_instance1 on host2, appName on oc4j_instance1 on host3,  (provided that host1, host2, host3 are all in the same cluster) Please note that One OPMN will be sufficient to find the list of all contexts from the entire cluster that satisfy the JNDI lookup query. You can do an experiment by shutting down appName on host1, and observe that OPMN on host1 will still be able to return you appname on host2 and appName on host3. When the PROVIDER URL reference a comma separated list of multiple OPMN servers When the JNDI propery java.naming.provider.url references a comma separated list of multiple URLs, the lookup will return the exact same things as with the single OPMN server: a list of qualified Contexts from the cluster. The purpose of having multiple OPMN servers is to provide high availability in the initial context creation, such that if OPMN at host1 is unavailable, client will try the lookup via OPMN on host2, and so on. After the initial lookup returns and cache a list of contexts, the JNDI URL(s) are no longer used in the same client session. That explains why removing the 3rd URL from the list of JNDI URLs will not stop the client from getting the EJB on the 3rd server. About the oracle.j2ee.rmi.loadBalance Property After the client acquires the list of contexts, it will cache it at the client side as “list of available RMI contexts”.  This list includes all the servers in the destination cluster. This list will stay in the cache until the client session (JVM) ends. The RMI load balancing against the destination cluster is happening at the client side, as the client is switching between the members of the list. Whether and how often the client will fresh the Context from the list of Context is based on the value of the  oracle.j2ee.rmi.loadBalance. The documentation at http://docs.oracle.com/cd/B31017_01/web.1013/b28958/rmi.htm#BABDGFBI list all the available values for the oracle.j2ee.rmi.loadBalance. Value Description client If specified, the client interacts with the OC4J process that was initially chosen at the first lookup for the entire conversation. context Used for a Web client (servlet or JSP) that will access EJBs in a clustered OC4J environment. If specified, a new Context object for a randomly-selected OC4J instance will be returned each time InitialContext() is invoked. lookup Used for a standalone client that will access EJBs in a clustered OC4J environment. If specified, a new Context object for a randomly-selected OC4J instance will be created each time the client calls Context.lookup(). Please note the regardless of the setting of oracle.j2ee.rmi.loadBalance property, the “refresh” only occurs at the client. The client can only choose from the "list of available context" that was returned and cached from the very first lookup. That is, the client will merely get a new Context object from the “list of available RMI contexts” from the cache at the client side. The client will NOT go to the OPMN server again to get the list. That also implies that if you are adding a node to the server cluster AFTER the client’s initial lookup, the client would not know it because neither the server nor the client will initiate a refresh of the “list of available servers” to reflect the new node. About High Availability (i.e. Resilience Against Node Failure of Remote OC4J Cluster) What we have discussed above is about load balancing. Let's also discuss high availability. This is how the High Availability works in RMI: when the client use the context but get an exception such as socket is closed, it knows that the server referenced by that Context is problematic and will try to get another unused Context from the “list of available contexts”. Again, this list is the list that was returned and cached at the very first lookup in the entire client session.

    Read the article

  • XAML2CPP 1.0.4.4

    - by Valter Minute
    My friends Arnaud Debaene and Alban Marie Lemonet of Adeneo Embedded worked on XAML2CPP fixing some bugs and adding new features to it. BugFixes: Corrected handling of x:Class attribute Corrected handling of namespaces for user controls Corrected code generated for user controls to fix a circular reference New features: Added handling of Storyboard generated events Added support for ItemsControl class. Many thanks to them for the great work they did on this utility and for sharing it with the community. You can download the new release here: http://cid-9b7b0aefe3514dc5.office.live.com/self.aspx/.Public/XAML2CPP.zip

    Read the article

  • Automating SQL Execution Plan analysis

    - by jchang
    Last year, I made my tool for automating execution plan analysis available on www.qdpma.com The original version could parse execution plans from sys.dm_exec_query_stats or dm_exec_cached_plans and generate a cross-reference of which execution plans employed each index. The DMV sys.dm_db_index_usage_stats shows how often each index is used, but not where, that is, which particular stored procedure or My latest version can now also 1) use the DMV sys.dm_exec_procedure_stats, 2) it can also get the...(read more)

    Read the article

  • APress Deal of the Day 16/August/2014 - Node.js Recipes

    - by TATWORTH
    Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2014/08/15/apress-deal-of-the-day-16august2014---node.js-recipes.aspxToday’s $10 Deal of the Day from APress at http://www.apress.com/9781430260585 is Node.js Recipes. “Node.js Recipes is your one-stop reference for solving Node.js problems. Filled with useful recipes that follow a problem/solution format, you can look up recipes for many situations that you may come across in your day-to-day server-side development. ”

    Read the article

  • 10.04 drops to '(initramfs)' prompt on boot

    - by David Yenor
    I'm not sure what to do to solve the problem, I received this error upon boot. mount: mounting /dev/disk/by-uuid/f60e3ce2-0237-45bb-bf07-581d0090cbc7 on /root failed: Invalid argument mount: mounting /dev on /root/dev failed: No such file or directory mount: mounting /sys on /root/sys failed: No such file or directory mount: mounting /proc on /root/proc failed: No such file or directory Target filesystem doesn't have /sbin/init. No init found. Try passing init= bootarg. BusyBox v1.13.3 (Ubuntu 1:1.13.3-1ubuntu11) built-in shell (ash) Enter 'help' for a list of built-in commands. (initramfs) _

    Read the article

  • SQL SERVER – Difference Between CURRENT_TIMESTAMP and GETDATE() – CURRENT_TIMESTAMP Equivalent in SQL Server

    - by pinaldave
    A common question – I often get from Oracle/MySQL Professionals: “What is the Equivalent to CURRENT_TIMESTAMP in SQL Server?” Here is a common question I often get from SQL Server Professionals: “What are differences between Difference Between CURRENT_TIMESTAMP and GETDATE ()?” Very simple question but have showed up so frequently that I feel like to write about it. Well in SQL Server GETDATE() is Equivalent to CURRENT_TIMESTAMP. However, if you use CURRENT_TIMESTAMP in your select statement it will work fine. You can see in the above example – both of them returns the same value. Now let us go to next question regarding difference between GETDATE and CURRENT_TIMESTAMP. Well, the matter of the fact, there is no difference between them in SQL Server (Reference Link). CURRENT_TIMESTAMP is an ANSI SQL function, whereas GETDATE is T-SQL implementation of the same function. Both of them derive value from the operating system of the computer on which SQL Server instance is running. Above discussion prompts another question – in this case, what should one use GETDATE or CURRENT_TIMESTAMP? Well, this is indeed tricky and interesting question. I think I am very comfortable using the GETDATE () so I will go to use it but a matter of the fact there is no right or wrong answer. If you want to follow ancient saying “When in Rome, do as the Romans do”, I suggest using the GETDATE (), or continue using CURRENT_TIMESTAMP. With that said, there is one very important property we all need to keep in mind. If you use CURRENT_TIMESTAMP while creating an object, they are automatically converted to GETDATE() and stored internally. To illustrate what I am suggesting here is the example - Create a table using the following script CREATE TABLE [dbo].[TestTable]( [Cold2] [datetime] NULL ) ON [PRIMARY] GO ALTER TABLE [dbo].[TestTable] ADD DEFAULT (CURRENT_TIMESTAMP) FOR [Cold2] GO Now go to SSMS and generate the script for the table and you will notice following syntax. CREATE TABLE [dbo].[TestTable]( [Cold2] [datetime] NULL ) ON [PRIMARY] GO ALTER TABLE [dbo].[TestTable] ADD DEFAULT (GETDATE()) FOR [Cold2] GO You can notice that SQL Server have automatically converted CURRENT_TIMESTAMP to GETDATE(). I guess this gives us an idea how they behave. Now go ahead and make your choice! Do let me know which one will you use CURRENT_TIMESTAMP or GETDATE () in the comments area. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL DateTime, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • So what *did* Alan Kay really mean by the term "object-oriented"?

    - by Charlie Flowers
    Reportedly, Alan Kay is the inventor of the term "object oriented". And he is often quoted as having said that what we call OO today is not what he meant. For example, I just found this on Google: I made up the term 'object-oriented', and I can tell you I didn't have C++ in mind -- Alan Kay, OOPSLA '97 I vaguely remember hearing something pretty insightful about what he did mean. Something along the lines of "message passing". Do you know what he meant? Can you fill in more details of what he meant and how it differs from today's common OO? Please share some references if you have any. Thanks.

    Read the article

  • Lubuntu 12.04 PPC slow startup and shutdown

    - by Carlo Bertuccini
    I've installed Lubuntu 12.04 on a Powerbook G4 (PowerPC 1GHz, 1 gb ram, Geforce MX 440). Everything works perfectly except the startup and shutdown. To startup my system I have to wait about 3 minutes (and similar time to shutdown) Giving a look @ /var/log/dmesg I noticed the following [drm] nouveau 0000:00:10.0: Detected an NV10 generation card (0x017900a5) checking generic (b8004000 151800) vs hw (b8000000 80000000) fb: conflicting fb hw usage nouveaufb vs 0Ffb NVDA,Displ - removing generic driver The only issue concerns Nouveau ... inside my /var/log/kern.log says what follows BUG: soft lockup - CPU#0 stuck for 22s! I've booted passing the "nouveau.modeset=0" parameter and the system boot in 15 seconds but with 4 bit graphics -- Any idea how to fix? Thanks in advance for any help

    Read the article

< Previous Page | 159 160 161 162 163 164 165 166 167 168 169 170  | Next Page >