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• Designing a system with different business rules for different customers

  - by user1595846

  My company is rewriting our proprietary business application. The current architecture is poorly done and inflexible. It is coded more procedural oriented as opposed to object oriented. It has become difficult to maintain. Our system is a web application written in .Net Webforms. I am considering ASP.Net MVC for the rewrite. We intend to rewrite it with a good, solid architecture with the goal of maintainability and reusable classes for some of our other systems and services. We would also like the system to be customizable for different customers in the event that we market the system. I am considering redesigning the system based on the layered architecture (Presentation, Business, Data Access layers) described in the Microsoft Patterns and Practices Application Architecture Guide. http://msdn.microsoft.com/en-us/library/ff650706.aspx Hopefully this isn't too open ended, but how would you recommend allowing for different business logic/rules for different customers? I'm aware of Windows Workflow Foundation, but from what I've read about it, it seems many business rules could be too complicated to handle there. Also, Can anyone point me to where I can download an example of a .net solution that is based on the Application Architecture Guide? I have already downloaded the Layered Architecture Solution Guidance and the Expense Sample on codeplex. I was looking for something a bit larger and more robust that I could step through the code and see how it works. If you feel there are better architectures to base our redesign on please feel free to share. I appreciate your help!

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• Complex, yet simple crafting system model

  - by KatShot

  I'm working on some arcade shooter/slasher, and the main logline is "Kick'em with everything you want". There's not so many enemies in GDD, main focus is on tons of weapons and gadgets to cause mayhem. To get weapon, you need to craft it, and now crafting system looks simple, like: 1) You got three slots for weapon parts (like A, B, C) 2) You collect misc weapon parts, and when you got atleast one for every slot, you can craft a weapon (for example, if you got A1, B1, B2, B3 and C1, you can craft such models - A1B1C1, A1B2C1, A1B3C1) As for me, this crafting system is too simple, because weapon parts will just fall from the top of screen, often enough. That's why I'm thinking about adding some more crafting system levels, like resources (collect 10 scrap pieces to make part A1 or C3), etc. My question is: How can i add some more complex, still simple, transparent levels in crafting system? upd. For example, in Minecraft or Terraria, first 5-10 crafting recipies quite transparent and simple IMHO. But then it turns into huge mess to understand, how to craft this or that (for example, fishing rod)

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• Iterate through deserialized xml object

  - by Bruce Adams

  I have a deserialized xml c# objet. I need to iterate through the oject to display all items, in this case there's just one, and display the name, colors and sizes for each item. The xml: <?xml version="1.0" encoding="utf-8"?> <Catalog Name="Example"> <Items> <Item Name="ExampleItem"> <Colors> <Color Name="Black" Value="#000" /> <Color Name="White" Value="#FFF" /> </Colors> <Sizes> <Size Name="Small" Value="10" /> <Size Name="Medium" Value="20" /> </Sizes> </Item> </Items> </Catalog> xsd.exe generated classes: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:2.0.50727.4927 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ using System.Xml.Serialization; // // This source code was auto-generated by xsd, Version=2.0.50727.42. // /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] [System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)] public partial class Catalog { private CatalogItemsItem[][] itemsField; private string nameField; /// <remarks/> [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified)] [System.Xml.Serialization.XmlArrayItemAttribute("Item", typeof(CatalogItemsItem[]), Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)] public CatalogItemsItem[][] Items { get { return this.itemsField; } set { this.itemsField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] public partial class CatalogItemsItem { private CatalogItemsItemColorsColor[][] colorsField; private CatalogItemsItemSizesSize[][] sizesField; private string nameField; /// <remarks/> [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified)] [System.Xml.Serialization.XmlArrayItemAttribute("Color", typeof(CatalogItemsItemColorsColor[]), Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)] public CatalogItemsItemColorsColor[][] Colors { get { return this.colorsField; } set { this.colorsField = value; } } /// <remarks/> [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified)] [System.Xml.Serialization.XmlArrayItemAttribute("Size", typeof(CatalogItemsItemSizesSize[]), Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)] public CatalogItemsItemSizesSize[][] Sizes { get { return this.sizesField; } set { this.sizesField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] public partial class CatalogItemsItemColorsColor { private string nameField; private string valueField; /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Value { get { return this.valueField; } set { this.valueField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] public partial class CatalogItemsItemSizesSize { private string nameField; private string valueField; /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Name { get { return this.nameField; } set { this.nameField = value; } } /// <remarks/> [System.Xml.Serialization.XmlAttributeAttribute()] public string Value { get { return this.valueField; } set { this.valueField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] [System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)] public partial class NewDataSet { private Catalog[] itemsField; /// <remarks/> [System.Xml.Serialization.XmlElementAttribute("Catalog")] public Catalog[] Items { get { return this.itemsField; } set { this.itemsField = value; } } } Deserialization code: System.Xml.Serialization.XmlSerializer xSerializer = new System.Xml.Serialization.XmlSerializer(typeof(Catalog)); TextReader reader = new StreamReader("catalog.xml"); Catalog catalog = (Catalog)xSerializer.Deserialize(reader); foreach (var item in catalog.Items) { } reader.Close(); When I setp through the code there is one item present in catalog.items, but it is empty, no name, colors or sizes. Any ideas what I need to do? Thanks

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• Issue with dynamic array Queue data structure with void pointer

  - by Nazgulled

  Hi, Maybe there's no way to solve this the way I'd like it but I don't know everything so I better ask... I've implemented a simple Queue with a dynamic array so the user can initialize with whatever number of items it wants. I'm also trying to use a void pointer as to allow any data type, but that's the problem. Here's my code: typedef void * QueueValue; typedef struct sQueueItem { QueueValue value; } QueueItem; typedef struct sQueue { QueueItem *items; int first; int last; int size; int count; } Queue; void queueInitialize(Queue **queue, size_t size) { *queue = xmalloc(sizeof(Queue)); QueueItem *items = xmalloc(sizeof(QueueItem) * size); (*queue)->items = items; (*queue)->first = 0; (*queue)->last = 0; (*queue)->size = size; (*queue)->count = 0; } Bool queuePush(Queue * const queue, QueueValue value, size_t val_sz) { if(isNull(queue) || isFull(queue)) return FALSE; queue->items[queue->last].value = xmalloc(val_sz); memcpy(queue->items[queue->last].value, value, val_sz); queue->last = (queue->last+1) % queue->size; queue->count += 1; return TRUE; } Bool queuePop(Queue * const queue, QueueValue *value) { if(isEmpty(queue)) return FALSE; *value = queue->items[queue->first].value; free(queue->items[queue->first].value); queue->first = (queue->first+1) % queue->size; queue->count -= 1; return TRUE; } The problem lies on the queuePop function. When I call it, I lose the value because I free it right away. I can't seem to solve this dilemma. I want my library to be generic and modular. The user should not care about allocating and freeing memory, that's the library's job. How can the user still get the value from queuePop and let the library handle all memory allocs/frees?

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• Multiple views and source list in a Core Data app

  - by Ellie P.

  I'm working on my first major Cocoa app for an undergraduate research project. The application is document-based and uses Core Data. One of the entities is an abstract entity, Page. Page is parent of several types of pages: ie PageWithHeaderAndFooter, PageWithTwoColumns, BasicPage etc. Page has attributes, such as title and author, that all pages have in common. Each specific type of page has a certain number of layout blocks (PageWithHeaderAndFooter has three: header, footer, body. BasicPage has one: body. etc.) Additionally, all Page subclasses define layout-specific implementations of certain methods. The other relevant entity is Style, which defines the visual look of a Page. (Think of Pages as HTML and Style as CSS.) I would like my app to have an iTunes/Mail-like source list with sections. (One section would be Pages, the other would be Styles.) I have a pretty good idea how to do the sectioned source list (this was a great help). However, after hours of headbanging and fruitless googling, here's what I can't figure out: Pages and Styles listed in the source list, and when you select one of them, all of the relevant fields for that object appear at the right (mostly NSTextViews, pop up menus, etc). I laid that out and did all of the bindings in Interface Builder. The problem is, if my source list contains different types of pages, how do I get a different view to display at the right depending on the type of page selected? For example, if a BasicPage is selected, I want just what you see above: the general page stuff and one NSTextView that corresponds to the one field body of BasicPage. But if I select a PageWithHeaderAndFooter, I want to display the general page stuff plus three NSTextViews (one for header, body, and footer.) If I have a Style selected, I want to display various pop up menus, color wells, etc. For the pages at least, we're only talking about one or more NSTextViews, each of which corresponds to a String attribute of the respective entity. How would you do this? Thank you for your help!

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• Crash in OS X Core Data Utility Tutorial

  - by vinogradov

  I'm trying to follow Apple's Core Data utility Tutorial. It was all going nicely, until... The tutorial uses a custom sub-class of NSManagedObject, called 'Run'. Run.h looks like this: #import <Foundation/Foundation.h> #import <CoreData/CoreData.h> @interface Run : NSManagedObject { NSInteger processID; } @property (retain) NSDate *date; @property (retain) NSDate *primitiveDate; @property NSInteger processID; @end Now, in Run.m we have an accessor method for the processID variable: - (void)setProcessID:(int)newProcessID { [self willChangeValueForKey:@"processID"]; processID = newProcessID; [self didChangeValueForKey:@"processID"]; } In main.m, we use functions to set up a managed object model and context, instantiate an entity called run, and add it to the context. We then get the current NSprocessInfo, in preparation for setting the processID of the run object. NSManagedObjectContext *moc = managedObjectContext(); NSEntityDescription *runEntity = [[mom entitiesByName] objectForKey:@"Run"]; Run *run = [[Run alloc] initWithEntity:runEntity insertIntoManagedObjectContext:moc]; NSProcessInfo *processInfo = [NSProcessInfo processInfo]; Next, we try to call the accessor method defined in Run.m to set the value of processID: [run setProcessID:[processInfo processIdentifier]]; And that's where it's crashing. The object run seems to exist (I can see it in the debugger), so I don't think I'm messaging nil; on the other hand, it doesn't look like the setProcessID: message is actually being received. I'm obviously still learning this stuff (that's what tutorials are for, right?), and I'm probably doing something really stupid. However, any help or suggestions would be gratefully received! ===MORE INFORMATION=== Following up on Jeremy's suggestions: The processID attribute in the model is set up like this: NSAttributeDescription *idAttribute = [[NSAttributeDescription alloc]init]; [idAttribute setName:@"processID"]; [idAttribute setAttributeType:NSInteger32AttributeType]; [idAttribute setOptional:NO]; [idAttribute setDefaultValue:[NSNumber numberWithInteger:-1]]; which seems a little odd; we are defining it as a scalar type, and then giving it an NSNumber object as its default value. In the associated class, Run, processID is defined as an NSInteger. Still, this should be OK - it's all copied directly from the tutorial. It seems to me that the problem is probably in there somewhere. By the way, the getter method for processID is defined like this: - (int)processID { [self willAccessValueForKey:@"processID"]; NSInteger pid = processID; [self didAccessValueForKey:@"processID"]; return pid; } and this method works fine; it accesses and unpacks the default int value of processID (-1). Thanks for the help so far!

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• Solr Facet Search spring-data-solr

  - by sv1

  I am new to Solr and we are using Spring-data for Solr I have a question may be its too simple but I am unable to comprehend. Basically I need to search on any field but I have a "zip" field as one of the facet fields. I have a Solr repository . (Am not sure if the annotations on the Repository are correct.) public interface MyRepository extends SolrCrudRepository<MyPOJO, String> { @Query(value = "*:*") @Facet(fields={"zip"}) public FacetPage<MyPOJO> findByQueryandAnno(String searchTerm,Pageable page); } In my Service class I am trying to call this methods by Injecting MyRepository like below public class MyService { @Inject MyRepository solrRepo; @Inject SolrTemplate solrTemplate; public FacetPage<MyPOJO> tryFacets(String searchString){ //Here is where I am struggling SimpleFacetQuery query = new SimpleQuery(new SimpleStringCriteria(searchString)); query.setFacetOptions(new FacetOptions("zip")); //Not sure how to get the Pageable object. //But the repository doesnt accept without it. return solrTemplate.queryForPage(query,{Pageable Instance to be passed here}) } From my jUnit I am loading context files needed for Solr and Spring //In jUnit the test method looks like this service.tryFacets("some value"); and it fails with - method not found in the service class at the call to the repository method. *********EDIT**************** As per ChristophStrobl's advice created a copyfield called multivaluedCopyField and the searchString argument works good. But the facet still isnt working...Now my code looks like this. I get the MyPOJO object as response but the facetcount and the faceted values are missing. public interface MyRepository extends SolrCrudRepository<MyPOJO, String> { @Query(value = "*:*") @Facet(fields={"zip"}) public FacetPage<MyPOJO> findByQueryandAnno(String searchTerm,Pageable page); } My service class looks like public class MyService { @Inject MyRepository solrRepo; public FacetPage<MyPOJO> tryFacets(String searchString){ //Here is where I am struggling SimpleFacetQuery query = new SimpleQuery(new SimpleStringCriteria(searchString)).setPageRequest new PageRequest(0,5)); query.setFacetOptions(new FacetOptions("zip")); FacetPage<MyPOJO> facetedPOJO= solrRepo.findByQueryandAnno(searchString,query.getPageRequest()); return facetedPOJO; } My jUnit method call is like service.tryFacets("some value");

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• Principles of Big Data By Jules J Berman, O&rsquo;Reilly Media Book Review

  - by Compudicted

  Originally posted on: http://geekswithblogs.net/Compudicted/archive/2013/11/04/principles-of-big-data-by-jules-j-berman-orsquoreilly-media.aspx A fantastic book! Must be part, if not yet, of the fundamentals of the Big Data as a field of science. Highly recommend to those who are into the Big Data practice. Yet, I confess this book is one of my best reads this year and for a number of reasons: The book is full of wisdom, intimate insight, historical facts and real life examples to how Big Data projects get conceived, operate and sadly, yes, sometimes die. But not only that, the book is most importantly is filled with valuable advice, accurate and even overwhelming amount of reference (from the positive side), and the author does not event stop there: there are numerous technical excerpts, links and examples allowing to quickly accomplish many daunting tasks or make you aware of what one needs to perform as a data practitioner (excuse my use of the word practitioner, I just did not find a better substitute to it to trying to reference all who face Big Data). Be aware that Jules Berman’s background is in medicine, naturally, this book discusses this subject a lot as it is very dear to the author’s heart I believe, this does not make this book any less significant however, quite the opposite, I trust if there is an area in science or practice where the biggest benefits can be ripped from Big Data projects it is indeed the medical science, let’s make Cancer history! On a personal note, for me as a database, BI professional it has helped to understand better the motives behind Big Data initiatives, their underwater rivers and high altitude winds that divert or propel them forward. Additionally, I was impressed by the depth and number of mining algorithms covered in it. I must tell this made me very curious and tempting to find out more about these indispensable attributes of Big Data so sure I will be trying stretching my wallet to acquire several books that go more in depth on several most popular of them. My favorite parts of the book, well, all of them actually, but especially chapter 9: Analysis, it is just very close to my heart. But the real reason is it let me see what I do with data from a different angle. And then the next - “Special Considerations”, they are just two logical parts. The writing language is of this book is very acceptable for all levels, I had no technical problem reading it in ebook format on my 8” tablet or a large screen monitor. If I would be asked to say at least something negative I have to state I had a feeling initially that the book’s first part reads like an academic material relaxing the reader as the book progresses forward. I admit I am impressed with Jules’ abilities to use several programming languages and OSS tools, bravo! And I agree, it is not too, too hard to grasp at least the principals of a modern programming language, which seems becomes a defacto knowledge standard item for any modern human being. So grab a copy of this book, read it end to end and make yourself shielded from making mistakes at any stage of your Big Data initiative, by the way this book also helps build better future Big Data projects. Disclaimer: I received a free electronic copy of this book as part of the O'Reilly Blogger Program.

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• Windows 7 Backup - Does the "system image" include all the files on my drive?

  - by Vaccano

  I have a new Dell Laptop that I have setup the way I like it. I want to use Windows 7 to do a backup and then restore that backup on a different hard drive (solid state). When I setup the backup info (manually) for Windows 7 Backup there is a little checkbox at the the bottom that says: Include a system image of drives: RECOVERY, OS (C:) I can also select to backup all my data on the C: drive (the only hard drive I have anything on) as well as some libraries (which are on my C: drive so no point in selecting those). The question I have is, does Windows 7 Backup just somehow know what needs to be restored (ie program files and Windows and the registry ....? Or is it really making a full restorable copy of the C: drive? (If the later is true then I don't need select the C: drive to be "backed up" if I don't plan to access the files except by restoring them right? (Because the system image will already have it all.)) So, which way is it? What is saved in the System Image?

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• How to Refresh or Reset Windows 8 without the System Reserved partition?

  - by Karan

  The article Refresh and reset your PC mentions exactly what happens during the refresh and reset operations in Windows 8: Refresh The PC boots into Windows RE. Windows RE scans the hard drive for your data, settings, and apps, and puts them aside (on the same drive). Windows RE installs a fresh copy of Windows. Windows RE restores the data, settings, and apps it has set aside into the newly installed copy of Windows. The PC restarts into the newly installed copy of Windows. Reset The PC boots into the Windows Recovery Environment (Windows RE). Windows RE erases and formats the hard drive partitions on which Windows and personal data reside. Windows RE installs a fresh copy of Windows. The PC restarts into the newly installed copy of Windows. It is my understanding that Windows RE (Recovery Environment) is included as part of the System Reserved partition created by default on the first hard disk. The size of this partition has gone up to 350 MB from the 100 MB it used to be in Vista/Windows 7, no doubt as a result of adding these features. Now we have already discussed how to skip the creation of this System Reserved partition during Setup. Basically, the same techniques that used to work with Windows 7 work with Windows 8 as well. What I want to know is, what will be the exact repercussions of not having the System Reserved partition in place? I assume Troubleshoot / Advanced options should still be available as before: But what about the Troubleshoot menu itself? Will the Refresh and Reset options disappear? Will they remain but be unavailable? Or possibly they will throw an error if selected? Also, will it be possible to access and successfully execute these options if installation media is available? Anything else that might be affected?

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• Do registry issues with Win7 persist through a recovery from a system image?

  - by user59089

  So I need a bit of advice, please; here's my situation: I have 1) a system image on an a brand new external 1 TB SATA drive, that I managed to successfully capture before my 2) primary system drive went down. I realize this is a fairly simple matter of buying a new primary drive and performing the recovery to the fresh disk...however, the issue is that I believe Win7 was also having some significant issues of its own--basically, Update unable to install updates, and Backup continually ditching the auto backup schedule. I'd been trying to address those issues when my system was still working, but it's been so fruitless, I'm convinced a Win7 re-install would be best, and now I'm concerned that if I was in fact having what I believe are likely registry-related issues before, that these will persist through a recovery--would that likely be correct? I'm mainly worried about recovering my files, so if I did a full recovery from the image, should I be able to then access my individual files, and copy them manually to an external drive, so I can then do a full re-install of Win7? Sory if this seems obvious, but I've never done a recovery before and just trying to make sure there's no red flags with what I have in mind...

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• How do you recreate the System Recovery environment in Windows 7?

  - by Howiecamp

  I'm running Windows 7 Home Premium RTM (64-bit) and I want to take advantage of the system recovery tools (eg the Command Prompt) without using the Windows 7 DVD. My understanding is that this environment (WinRE) should be installed to your HDD by default as part of the Windows 7 installation. However, when I hit F8 on boot and select "Repair", I get: Windows failed to start. A recent hardware or software change might be the cause. To fix the problem... Status: 0xc000000e Info: The boot selection failed because a required device is inaccessible. The "Info" line seems like the smoking gun. My next step was to boot from the Windows 7 DVD, and choose "Repair". It indicated my Recovery Environment wasn't on the Windows 7 boot menu (perfect) and offered to fix it. I said yes and rebooted, however same issue as above. In addition, when I booted in to Windows 7 and I looked at the boot menu options, the recovery/repair option was not there. Only my Windows installation. Finally, I ran the Disk Management tool (diskmgmt.msc) and took a look at the contents of my "System Reserved" partition (which was set to "Active" as normal). It's unclear to me what the contents should look like, however it is my understanding that the WinRE environment gets installed to this partition. (As part of the above troubleshooting I followed http://superuser.com/questions/25728/how-to-fix-windows-7-boot-process which lead to http://www.sevenforums.com/tutorials/668-system-recovery-options.html).

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• Optimal storage of data structure for fast lookup and persistence

  - by Mikael Svenson

  Scenario I have the following methods: public void AddItemSecurity(int itemId, int[] userIds) public int[] GetValidItemIds(int userId) Initially I'm thinking storage on the form: itemId -> userId, userId, userId and userId -> itemId, itemId, itemId AddItemSecurity is based on how I get data from a third party API, GetValidItemIds is how I want to use it at runtime. There are potentially 2000 users and 10 million items. Item id's are on the form: 2007123456, 2010001234 (10 digits where first four represent the year). AddItemSecurity does not have to perform super fast, but GetValidIds needs to be subsecond. Also, if there is an update on an existing itemId I need to remove that itemId for users no longer in the list. I'm trying to think about how I should store this in an optimal fashion. Preferably on disk (with caching), but I want the code maintainable and clean. If the item id's had started at 0, I thought about creating a byte array the length of MaxItemId / 8 for each user, and set a true/false bit if the item was present or not. That would limit the array length to little over 1mb per user and give fast lookups as well as an easy way to update the list per user. By persisting this as Memory Mapped Files with the .Net 4 framework I think I would get decent caching as well (if the machine has enough RAM) without implementing caching logic myself. Parsing the id, stripping out the year, and store an array per year could be a solution. The ItemId - UserId[] list can be serialized directly to disk and read/write with a normal FileStream in order to persist the list and diff it when there are changes. Each time a new user is added all the lists have to updated as well, but this can be done nightly. Question Should I continue to try out this approach, or are there other paths which should be explored as well? I'm thinking SQL server will not perform fast enough, and it would give an overhead (at least if it's hosted on a different server), but my assumptions might be wrong. Any thought or insights on the matter is appreciated. And I want to try to solve it without adding too much hardware :) [Update 2010-03-31] I have now tested with SQL server 2008 under the following conditions. Table with two columns (userid,itemid) both are Int Clustered index on the two columns Added ~800.000 items for 180 users - Total of 144 million rows Allocated 4gb ram for SQL server Dual Core 2.66ghz laptop SSD disk Use a SqlDataReader to read all itemid's into a List Loop over all users If I run one thread it averages on 0.2 seconds. When I add a second thread it goes up to 0.4 seconds, which is still ok. From there on the results are decreasing. Adding a third thread brings alot of the queries up to 2 seonds. A forth thread, up to 4 seconds, a fifth spikes some of the queries up to 50 seconds. The CPU is roofing while this is going on, even on one thread. My test app takes some due to the speedy loop, and sql the rest. Which leads me to the conclusion that it won't scale very well. At least not on my tested hardware. Are there ways to optimize the database, say storing an array of int's per user instead of one record per item. But this makes it harder to remove items.

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• Moving to .net 4 results in System.Transactions Critical: 0

  - by john

  Hi I have fully working project in .net 3.5SP1, with EF 1 ORM. I tried to upgrade to .net 4. No issue while upgrading... Then i ran the project and got a NullExecptionError, with no stack trace... and no way to debug. Looking at the output windows i can read this: System.Transactions Critical: 0 : <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Critical"><TraceIdentifier>http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/Unhandled</TraceIdentifier><Description>Unhandled exception</Description><AppDomain>OTCSouscriptions.vshost.exe</AppDomain><Exception><ExceptionType>System.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType><Message>Object reference not set to an instance of an object.</Message><StackTrace> at System.Windows.StyleHelper.GetInstanceValue(UncommonField`1 dataField, DependencyObject container, FrameworkElement feChild, FrameworkContentElement fceChild, Int32 childIndex, DependencyProperty dp, Int32 i, EffectiveValueEntry&amp;amp; entry) at System.Windows.FrameworkTemplate.ReceivePropertySet(Object targetObject, XamlMember member, Object value, DependencyObject templatedParent) at System.Windows.FrameworkTemplate.&amp;lt;&amp;gt;c__DisplayClass6.&amp;lt;LoadOptimizedTemplateContent&amp;gt;b__4(Object sender, XamlSetValueEventArgs setArgs) at System.Xaml.XamlObjectWriter.OnSetValue(Object eventSender, XamlMember member, Object value) at System.Xaml.XamlObjectWriter.Logic_ApplyPropertyValue(ObjectWriterContext ctx, XamlMember prop, Object value, Boolean onParent) at System.Xaml.XamlObjectWriter.Logic_DoAssignmentToParentProperty(ObjectWriterContext ctx) at System.Xaml.XamlObjectWriter.Logic_AssignProvidedValue(ObjectWriterContext ctx) at System.Xaml.XamlObjectWriter.WriteEndObject() at System.Xaml.XamlWriter.WriteNode(XamlReader reader) at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlReader templateReader, XamlObjectWriter currentWriter) Any help appreciated... Thanks John

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• No data when attempting to get JSONP data from cross domain PHP script

  - by Alex

  I am trying to pull latitude and longitude values from another server on a different domain using a singe id string. I am not very familiar with JQuery, but it seems to be the easiest way to go about getting around the same origin problem. I am unable to use iframes and I cannot install PHP on the server running this javascript, which is forcing my hand on this. My queries appear to be going through properly, but I am not getting any results back. I was hoping someone here might have an idea that could help, seeing as I probably wouldn't recognize most obvious errors here. My javascript function is: var surl = "http://...omitted.../pull.php"; var idnum = 5a; //in practice this is defined above alert("BEFORE"); $.ajax({ url: surl, data: {id: idnum}, dataType: "jsonp", jsonp : "callback", jsonp: "jsonpcallback", success: function (rdata) { alert(rdata.lat + ", " + rdata.lon); } }); alert("BETWEEN"); function jsonpcallback(rtndata) { alert("CALLED"); alert(rtndata.lat + ", " + rtndata.lon); } alert("AFTER"); When my javascript is run, the BEFORE, BETWEEN and AFTER alerts are displayed. The CALLED and other jsonpcallback alerts are not shown. Is there another way to tell if the jsoncallback function has been called? Below is the PHP code I have running on the second server. I added the count table to my database just so that I can tell when this script is run. Every time I call the javascript, count has had an extra item inserted and the id number is correct. <?php header("content-type: application/json"); if (isset($_GET['id']) || isset($_POST['id'])){ $db_handle = mysql_connect($server, $username, $password); if (!$db_handle) { die('Could not connect: ' . mysql_error()); } $db_found = mysql_select_db($database, $db_handle); if ($db_found) { if (isset($_POST['id'])){ $SQL = sprintf("SELECT * FROM %s WHERE loc_id='%s'", $loctable, mysql_real_escape_string($_POST['id'])); } if (isset($_GET['id'])){ $SQL = sprintf("SELECT * FROM %s WHERE loc_id='%s'", $loctable, mysql_real_escape_string($_GET['id'])); } $result = mysql_query($SQL, $db_handle); $db_field = mysql_fetch_assoc($result); $rtnjsonobj -> lat = $db_field["lat"]; $rtnjsonobj -> lon = $db_field["lon"]; if (isset($_POST['id'])){ echo $_POST['jsonpcallback']. '('. json_encode($rtnjsonobj) . ')'; } if (isset($_GET['id'])){ echo $_GET['jsonpcallback']. '('. json_encode($rtnjsonobj) . ')'; } $SQL = sprintf("INSERT INTO count (bullshit) VALUES ('%s')", $_GET['id']); $result = mysql_query($SQL, $db_handle); $db_field = mysql_fetch_assoc($result); } mysql_close($db_handle); } else { $rtnjsonobj -> lat = 404; $rtnjsonobj -> lon = 404; echo $_GET['jsonpcallback']. '('. json_encode($rtnjsonobj) . ')'; }?> I am not entirely sure if the jsonp returned by this PHP is correct. When I go directly to the PHP script without including any parameters, I do get the following. ({"lat":404,"lon":404}) The callback function is not included, but that much can be expected when it isn't included in the original call. Does anyone have any idea what might be going wrong here? Thanks in advance!

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• JAVA-SQL- Data Migration - ResultSets comparing Failing JUnit test

  - by user1865053

  I CANNOT get this JUnit Test to pass for the life of me. Can somebody point out where this has gone wrong. I am doing a data migration(MSSQL SERVER 2005), but I have the sourceDBUrl and the targetDCUrl the same URL so to narrow it down to syntax errors. So that is what I have, a syntax error. I am comparing the results of a table for the query SELECT programmeapproval, resourceapproval FROM tr_timesheet WHERE timesheetid = ? and the test always fails, but passes for other junit tests I have developed. I created 3 diffemt resultSetsEqual methods and none work. Yet, some other JUnit tests I have developed have PASSED. THE QUERY: SELECT timesheetid, programmeapproval, resourceapproval FROM tr_timesheet Returns three columns timesheetid (PK,int, not null) (populated with a range of numbers 2240 - 2282) programmeapproval (smallint,not null) (populated with the number 1 in every field) resourceapproval (smallint, not null) (populated with a number 1 in every field) When I run the query that is embedded in the code it only returns one row with the programmeapproval and resourceapproval columns and both field populated with the number 1. I have all jdbc drivers correctly installed and tested for connectivity. The JUnit Test is failing at this point according to the IDE. assertTrue(helper.resultSetsEqual2(sourceVal,targetVal)); This is the code: /*THIS IS A JUNIT CLASS****? package a7.unittests.dao; import static org.junit.Assert.assertTrue; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.Types; import org.junit.Test; import artemispm.tritonalerts.TimesheetAlert; public class UnitTestTimesheetAlert { @Test public void testQUERY_CHECKALERT() throws Exception{ UnitTestHelper helper = new UnitTestHelper(); Connection con = helper.getConnection(helper.sourceDBUrl); Connection conTarget = helper.getConnection(helper.targetDBUrl); PreparedStatement stmt = con.prepareStatement("select programmeapproval, resourceapproval from tr_timesheet where timesheetid = ?"); stmt.setInt(1, 2240); ResultSet sourceVal = stmt.executeQuery(); stmt = conTarget.prepareStatement("select programmeapproval, resourceapproval from tr_timesheet where timesheetid = ?"); stmt.setInt(1,2240); ResultSet targetVal = stmt.executeQuery(); assertTrue(helper.resultSetsEqual2(sourceVal,targetVal)); }} /*END**/ /*THIS IS A REGULAR CLASS**/ package a7.unittests.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; public class UnitTestHelper { static String sourceDBUrl = "jdbc:sqlserver://127.0.0.1:1433;databaseName=a7itm;user=a7user;password=a7user"; static String targetDBUrl = "jdbc:sqlserver://127.0.0.1:1433;databaseName=a7itm;user=a7user;password=a7user"; public Connection getConnection(String url)throws Exception{ return DriverManager.getConnection(url); } public boolean resultSetsEqual3 (ResultSet rs1, ResultSet rs2) throws SQLException { int col = 1; //ResultSetMetaData metadata = rs1.getMetaData(); //int count = metadata.getColumnCount(); while (rs1.next() && rs2.next()) { final Object res1 = rs1.getObject(col); final Object res2 = rs2.getObject(col); // Check values if (!res1.equals(res2)) { throw new RuntimeException(String.format("%s and %s aren't equal at common position %d", res1, res2, col)); } // rs1 and rs2 must reach last row in the same iteration if ((rs1.isLast() != rs2.isLast())) { throw new RuntimeException("The two ResultSets contains different number of columns!"); } } return true; } public boolean resultSetsEqual (ResultSet source, ResultSet target) throws SQLException{ while(source.next()) { target.next(); ResultSetMetaData metadata = source.getMetaData(); int count = metadata.getColumnCount(); for (int i =1; i<=count; i++) { if(source.getObject(i) != target.getObject(i)) { return false; } } } return true; } public boolean resultSetsEqual2 (ResultSet source, ResultSet target) throws SQLException{ while(source.next()) { target.next(); ResultSetMetaData metadata = source.getMetaData(); int count = metadata.getColumnCount(); for (int i =1; i<=count; i++) { if(source.getObject(i).equals(target.getObject(i))) { return false; } } } return true; } } /END***/ /*PASTED NEW CLASS - THIS IS A JUNIT TEST CLASS*/ package a7.unittests.dao; import static org.junit.Assert.*; import java.sql.Connection; import java.sql.DriverManager; import org.junit.Test; public class TestDatabaseConnection { @Test public void testConnection() throws Exception{ UnitTestHelper helper = new UnitTestHelper(); Connection con = helper.getConnection(helper.sourceDBUrl); Connection conTarget = helper.getConnection(helper.targetDBUrl); assertTrue(con != null && conTarget != null); } } /**END***/

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• During Spring unit test, data written to db but test not seeing the data

  - by richever

  I wrote a test case that extends AbstractTransactionalJUnit4SpringContextTests. The single test case I've written creates an instance of class User and attempts to write it to the database using Hibernate. The test code then uses SimpleJdbcTemplate to execute a simple select count(*) from the user table to determine if the user was persisted to the database or not. The test always fails though. I was suspect because in the Spring controller I wrote, the ability to save an instance of User to the db is successful. So I added the Rollback annotation to the unit test and sure enough, the data is written to the database since I can even see it in the appropriate table -- the transaction isn't rolled back when the test case is finished. Here's my test case: @ContextConfiguration(locations = { "classpath:context-daos.xml", "classpath:context-dataSource.xml", "classpath:context-hibernate.xml"}) public class UserDaoTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired private UserDao userDao; @Test @Rollback(false) public void teseCreateUser() { try { UserModel user = randomUser(); String username = user.getUserName(); long id = userDao.create(user); String query = "select count(*) from public.usr where usr_name = '%s'"; long count = simpleJdbcTemplate.queryForLong(String.format(query, username)); Assert.assertEquals("User with username should be in the db", 1, count); } catch (Exception e) { e.printStackTrace(); Assert.assertNull("testCreateUser: " + e.getMessage()); } } } I think I was remiss by not adding the configuration files. context-hibernate.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd> <bean id="namingStrategy" class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean"> <property name="staticField"> <value>org.hibernate.cfg.ImprovedNamingStrategy.INSTANCE</value> </property> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean" destroy-method="destroy" scope="singleton"> <property name="namingStrategy"> <ref bean="namingStrategy"/> </property> <property name="dataSource" ref="dataSource"/> <property name="mappingResources"> <list> <value>com/company/model/usr.hbm.xml</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.use_sql_comments">true</prop> <prop key="hibernate.query.substitutions">yes 'Y', no 'N'</prop> <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop> <prop key="hibernate.cache.use_query_cache">true</prop> <prop key="hibernate.cache.use_minimal_puts">false</prop> <prop key="hibernate.cache.use_second_level_cache">true</prop> <prop key="hibernate.current_session_context_class">thread</prop> </props> </property> </bean> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"/> <property name="nestedTransactionAllowed" value="false" /> </bean> <bean id="transactionInterceptor" class="org.springframework.transaction.interceptor.TransactionInterceptor"> <property name="transactionManager"> <ref local="transactionManager"/> </property> <property name="transactionAttributes"> <props> <prop key="create">PROPAGATION_REQUIRED</prop> <prop key="delete">PROPAGATION_REQUIRED</prop> <prop key="update">PROPAGATION_REQUIRED</prop> <prop key="*">PROPAGATION_SUPPORTS,readOnly</prop> </props> </property> </bean> </beans> context-dataSource.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="org.postgresql.Driver" /> <property name="jdbcUrl" value="jdbc\:postgresql\://localhost:5432/company_dev" /> <property name="user" value="postgres" /> <property name="password" value="postgres" /> </bean> </beans> context-daos.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="extendedFinderNamingStrategy" class="com.company.dao.finder.impl.ExtendedFinderNamingStrategy"/> <bean id="finderIntroductionAdvisor" class="com.company.dao.finder.impl.FinderIntroductionAdvisor"/> <bean id="abstractDaoTarget" class="com.company.dao.impl.GenericDaoHibernateImpl" abstract="true" depends-on="sessionFactory"> <property name="sessionFactory"> <ref bean="sessionFactory"/> </property> <property name="namingStrategy"> <ref bean="extendedFinderNamingStrategy"/> </property> </bean> <bean id="abstractDao" class="org.springframework.aop.framework.ProxyFactoryBean" abstract="true"> <property name="interceptorNames"> <list> <value>transactionInterceptor</value> <value>finderIntroductionAdvisor</value> </list> </property> </bean> <bean id="userDao" parent="abstractDao"> <property name="proxyInterfaces"> <value>com.company.dao.UserDao</value> </property> <property name="target"> <bean parent="abstractDaoTarget"> <constructor-arg> <value>com.company.model.UserModel</value> </constructor-arg> </bean> </property> </bean> </beans> Some of this I've inherited from someone else. I wouldn't have used the proxying that is going on here because I'm not sure it's needed but this is what I'm working with. Any help much appreciated.

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• How to Fix “Error occurred in deployment step ‘Activate Features’: System.TimeoutException:”

  - by ybbest

  Problem: When deploying a SharePoint2013 workflow using Visual Studio, I got the following Error: Error occurred in deployment step ‘Activate Features’: System.TimeoutException: The HTTP request has timed out after 20000 milliseconds. —> System.Net.WebException: The request was aborted: The request was canceled. at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at Microsoft.Workflow.Client.HttpGetResponseAsyncResult`1.OnGotResponse(IAsyncResult result) — End of inner exception stack trace — at Microsoft.Workflow.Common.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.Workflow.Client.Ht Analysis: After reading AC’s blogpost and I find out the issue is to do with the service bus. Then I found out the following services are not started Solution: So I start the Service Bus Gateway and Service Bus Message Broker and the problem goes away. References: SharePoint 2013 Workflow – Advanced Workflow Debugging with Fiddler

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• Error: The base type 'System.Web.UI.MasterPage' is not allowed for this page

  - by Patrick Olurotimi Ige

  I came across this error when i was trying to ajaxify my sharepoint site. After adding the AjaxifyMoss from the codeplex  developed by Richard Finn. And tried loading my site i got the error Error: The base type 'System.Web.UI.MasterPage' is not allowed for this page So  i decided to check the web.config and i noticed the SafeControl tag doesn't have the .Net 2.0 assembly included despite the fact i added both vsersios 2.0 and 3.5. Its possible the.Net  3.5 assebply overwrote the 2.0. Anyway after i added the below which is the 2.0 verison       <SafeControl Assembly="System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Namespace="System.Web.UI" TypeName="*" Safe="True" AllowRemoteDesigner="True" />  And refreshed my page. It worked

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• The configuration section 'system.web.extensions' cannot be read because it is missing a section declaration

  - by Jeff Widmer

  After upgrading an ASP.NET application from .NET Framework 3.5 to .NET Framework 4.0 I ran into the following error message dialog when trying to view any of the modules in IIS on the server. What happened is during the upgrade, the web.config file was automatically converted for .NET Framework 4.0.  This left behind an empty system.web.extensions section: It was an easy fix to resolve, just remove the unused system.web.extensions section.   ERROR DIALOG TEXT: --------------------------- ASP --------------------------- There was an error while performing this operation. Details: Filename: \\?\web.config Line number: 171 Error: The configuration section 'system.web.extensions' cannot be read because it is missing a section declaration --------------------------- OK   ---------------------------

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• Running Unity 2d - Does not work on actual system but works fine in VM

  - by Dylan

  So I'm running Ubuntu 10.10 and I cannot get Unity 2d to work with my system. This is particularly frustrating as it works just fine in all the VMs I've tested it on. I actually really like Unity and I want to get to know it (in part) before Ubuntu 11.04. I checked Synaptic and it looks like everything's there. The only thing not installed are dev libs and so on. Should I install those as well? Obviously the difference between my system and a VM is that the VM is running off a basically brand new OS. I only use VMs to test new stuff out and remake them often, so my only guess is that I have something installed on my system that is preventing Unity from running. Any thoughts?

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• How Windows 8's Backup System Differs From Windows 7's

  - by Chris Hoffman

  Windows 8 contains a completely revamped backup system. Windows 8’s File History replaces Windows 7’s Windows Backup – if you use Windows Backup and update to Windows 8, you’ll find quite a few differences. Microsoft redesigned Windows’ backup features because less than 5% of PCs used Windows Backup. The new File History system is designed to be simple to set up and work automatically in the background. This post will focus on the differences between File History and the Windows Backup feature you may be familiar with from Windows 7 – check out our full walkthrough of File History for more information. HTG Explains: What The Windows Event Viewer Is and How You Can Use It HTG Explains: How Windows Uses The Task Scheduler for System Tasks HTG Explains: Why Do Hard Drives Show the Wrong Capacity in Windows?

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• Performance impact: What is the optimal payload for SqlBulkCopy.WriteToServer()?

  - by Linchi Shea

  For many years, I have been using a C# program to generate the TPC-C compliant data for testing. The program relies on the SqlBulkCopy class to load the data generated by the program into the SQL Server tables. In general, the performance of this C# data loader is satisfactory. Lately however, I found myself in a situation where I needed to generate a much larger amount of data than I typically do and the data needed to be loaded within a confined time frame. So I was driven to look into the code...(read more)

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• Architecture strategies for a complex competition scoring system

  - by mikewassmer

  Competition description: There are about 10 teams competing against each other over a 6-week period. Each team's total score (out of a 1000 total available points) is based on the total of its scores in about 25,000 different scoring elements. Most scoring elements are worth a small fraction of a point and there will about 10 X 25,000 = 250,000 total raw input data points. The points for some scoring elements are awarded at frequent regular time intervals during the competition. The points for other scoring elements are awarded at either irregular time intervals or at just one moment in time. There are about 20 different types of scoring elements. Each of the 20 types of scoring elements has a different set of inputs, a different algorithm for calculating the earned score from the raw inputs, and a different number of total available points. The simplest algorithms require one input and one simple calculation. The most complex algorithms consist of hundreds or thousands of raw inputs and a more complicated calculation. Some types of raw inputs are automatically generated. Other types of raw inputs are manually entered. All raw inputs are subject to possible manual retroactive adjustments by competition officials. Primary requirements: The scoring system UI for competitors and other competition followers will show current and historical total team scores, team standings, team scores by scoring element, raw input data (at several levels of aggregation, e.g. daily, weekly, etc.), and other metrics. There will be charts, tables, and other widgets for displaying historical raw data inputs and scores. There will be a quasi-real-time dashboard that will show current scores and raw data inputs. Aggregate scores should be updated/refreshed whenever new raw data inputs arrive or existing raw data inputs are adjusted. There will be a "scorekeeper UI" for manually entering new inputs, manually adjusting existing inputs, and manually adjusting calculated scores. Decisions: Should the scoring calculations be performed on the database layer (T-SQL/SQL Server, in my case) or on the application layer (C#/ASP.NET MVC, in my case)? What are some recommended approaches for calculating updated total team scores whenever new raw inputs arrives? Calculating each of the teams' total scores from scratch every time a new input arrives will probably slow the system to a crawl. I've considered some kind of "diff" approach, but that approach may pose problems for ad-hoc queries and some aggegates. I'm trying draw some sports analogies, but it's tough because most games consist of no more than 20 or 30 scoring elements per game (I'm thinking of a high-scoring baseball game; football and soccer have fewer scoring events per game). Perhaps a financial balance sheet analogy makes more sense because financial "bottom line" calcs may be calculated from 250,000 or more transactions. Should I be making heavy use of caching for this application? Are there any obvious approaches or similar case studies that I may be overlooking?

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• System Variables, Stored Procedures or Functions for Meta Data

  - by BuckWoody

  Whenever you want to know something about SQL Server’s configuration, whether that’s the Instance itself or a database, you have a few options. If you want to know “dynamic” data, such as how much memory or CPU is consumed or what a particular query is doing, you should be using the Dynamic Management Views (DMVs) that you can read about here: http://msdn.microsoft.com/en-us/library/ms188754.aspx  But if you’re looking for how much memory is installed on the server, the version of the Instance, the drive letters of the backups and so on, you have other choices. The first of these are system variables. You access these with a SELECT statement, and they are useful when you need a discrete value for use, say in another query or to put into a table. You can read more about those here: http://msdn.microsoft.com/en-us/library/ms173823.aspx You also have a few stored procedures you can use. These often bring back a lot more data, pre-formatted for the screen. You access these with the EXECUTE syntax. It is a bit more difficult to take the data they return and get a single value or place the results in another table, but it is possible. You can read more about those here: http://msdn.microsoft.com/en-us/library/ms187961.aspx Yet another option is to use a system function, which you access with a SELECT statement, which also brings back a discrete value that you can use in a test or to place in another table. You can read about those here: http://msdn.microsoft.com/en-us/library/ms187812.aspx  By the way, many of these constructs simply query from tables in the master or msdb databases for the Instance or the system tables in a user database. You can get much of the information there as well, and there are even system views in each database to show you the meta-data dealing with structure – more on that here: http://msdn.microsoft.com/en-us/library/ms186778.aspx  Some of these choices are the only way to get at a certain piece of data. But others overlap – you can use one or the other, they both come back with the same data. So, like many Microsoft products, you have multiple ways to do the same thing. And that’s OK – just research what each is used for and how it’s intended to be used, and you’ll be able to select (pun intended) the right choice. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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