Search Results

Search found 16903 results on 677 pages for 'single responsibility'.

Page 92/677 | < Previous Page | 88 89 90 91 92 93 94 95 96 97 98 99  | Next Page >

• SQL SERVER – Reducing Page Contention on TempDB

  - by pinaldave

  I have recently received following email. “We are using TraceFlag 1118 to reduce the tempDB contention on our servers (2000 and 2005). What is your opinion? We have read lots of material, would you please answer me in single line.” Wow, this was very interesting question. What intrigued me was the second last where I am asked to answer in a single line. There is something about this strong email, I feel like blogging it here. I think I can talk over this subject forever – well, there is no clear answer. There are so many caveats about everything.  Again, I must stay honest to the request about answering in single line. I also do not like to answer which is YES/NO. What should I do? Let me ask this question to community today? What will you answer to this email? Let me start this by answering it myself in one line and taking one side. “I enable this trace flag in SQL Server 2000 without hot patch or service pack and not in later versions (2005+) onwards as code is improved”. What do you do in this case? The best answer will feature in this blog with due credit. Regarding further read and hint here is Microsoft KB which I think is very helpful. In quick summary: (Read KB for accuracy) When any page is allocated first 8 pages are allocated in mixed extended. This trace flag allocates uniform extended at the time, reducing contention. You can enable this trace flag at startup. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL TempDB, TempDB

  Read the article

• Multiple possible jsp views for a request

  - by Karl Walsh

  I'm looking to offer the user some way of changing how a single page looks based on some pre-defined jsps. i.e. Two or more jsp's contain similar information, and would be backed by a single controller method. The controller would decide which view to return. Is there a common way of achieving this? At the moment I have some administration screens where I control a list of possible views. The user can then choose which one to see from a drop-down. My current issue is that I don't know how to confirm (at the admin screen) that the view is valid. Is there a way of asking spring for all possible views so I can filter them and resent a drop-down on the admin screen rather than a free text field? If not is there a way of asking spring if a single view is valid? All these views will reside under a common directory, so it would probably be possible to scan recursively from that point and build a list of possible views. This goes beyond simply changing the css, since the page content might be different despite being backed by the same model.

  Read the article

• Is there a Unix/Linux platform equivalent of Telligent Community (formerly Community Server)?

  - by Scott A. Lawrence

  Telligent Community combines blogs, wikis, forums, and file-sharing capabilities into a single product with single sign-on, using all Microsoft technologies. Is there an equivalent offering that runs on Unix/Linux? Or would I have to pick and choose individual product offerings and figure out another option for single sign-on across them? Are there plug-ins for something like WordPress or MovableType that might add the necessary functionality? A friend of mine is looking to add a "members-only" area to her company's website, and since they're hosted on Dreamhost (and can't afford StackExchange pricing yet), I'm trying to find other options for them.

  Read the article

• printable PHP manual - 'all but the Function Reference section'

  - by JW01

  My Motivation I find it easier to learn things by reading 'offline'. I'd like to lean back and read the narrative part of a paper version of the official php manual. My Scuppered Plan My plan was to download the manual, print all but the Function Reference section and then read it. I have downloaded the "Single HTML file" version of the manual from the php.net download page. (That version did not contain any images, so I patched-in the ones from the Many HTML files version with no problem.) My plan was to open that "Single HTML file" in an HTML editor, delete the Function Reference section then print it out. Unfortunately, although I have tried three different editors, I have not been able to successfully load-up that massive html file to be able to edit it. Its about (~40MB). I started to look into the phpdoc framework with a view to rendering my own html docs from the source...but that's a steep learning curve for a newby..and is a last resort. I would use a file splitter, but they tend to split files crudely with no regard for html/xml/xhtml sematics. So the question is... Does anyone know know where you can download the php manual in a version that is a kind of half-way house between the 'Single HTML file' and the 'Many HTML files'? Ideally with the docs split into 3 parts: File 1 - stuff before the function reference File 2 - function reference File 3 - stuff after the function reference Or Can you suggest any editors/tools will enable me to split up this file myself?

  Read the article

• C#: Why Decorate When You Can Intercept

  - by James Michael Hare

  We've all heard of the old Decorator Design Pattern (here) or used it at one time or another either directly or indirectly.  A decorator is a class that wraps a given abstract class or interface and presents the same (or a superset) public interface but "decorated" with additional functionality.   As a really simplistic example, consider the System.IO.BufferedStream, it itself is a descendent of System.IO.Stream and wraps the given stream with buffering logic while still presenting System.IO.Stream's public interface:   1: Stream buffStream = new BufferedStream(rawStream); Now, let's take a look at a custom-code example.  Let's say that we have a class in our data access layer that retrieves a list of products from a database:  1: // a class that handles our CRUD operations for products 2: public class ProductDao 3: { 4: ... 5:  6: // a method that would retrieve all available products 7: public IEnumerable<Product> GetAvailableProducts() 8: { 9: var results = new List<Product>(); 10:  11: // must create the connection 12: using (var con = _factory.CreateConnection()) 13: { 14: con.ConnectionString = _productsConnectionString; 15: con.Open(); 16:  17: // create the command 18: using (var cmd = _factory.CreateCommand()) 19: { 20: cmd.Connection = con; 21: cmd.CommandText = _getAllProductsStoredProc; 22: cmd.CommandType = CommandType.StoredProcedure; 23:  24: // get a reader and pass back all results 25: using (var reader = cmd.ExecuteReader()) 26: { 27: while(reader.Read()) 28: { 29: results.Add(new Product 30: { 31: Name = reader["product_name"].ToString(), 32: ... 33: }); 34: } 35: } 36: } 37: }            38:  39: return results; 40: } 41: } Yes, you could use EF or any myriad other choices for this sort of thing, but the germaine point is that you have some operation that takes a non-trivial amount of time.  What if, during the production day I notice that my application is performing slowly and I want to see how much of that slowness is in the query versus my code.  Well, I could easily wrap the logic block in a System.Diagnostics.Stopwatch and log the results to log4net or other logging flavor of choice: 1:     // a class that handles our CRUD operations for products 2:     public class ProductDao 3:     { 4:         private static readonly ILog _log = LogManager.GetLogger(typeof(ProductDao)); 5:         ... 6:         7:         // a method that would retrieve all available products 8:         public IEnumerable<Product> GetAvailableProducts() 9:         { 10:             var results = new List<Product>(); 11:             var timer = Stopwatch.StartNew(); 12:             13:             // must create the connection 14:             using (var con = _factory.CreateConnection()) 15:             { 16:                 con.ConnectionString = _productsConnectionString; 17:                 18:                 // and all that other DB code... 19:                 ... 20:             } 21:             22:             timer.Stop(); 23:             24:             if (timer.ElapsedMilliseconds > 5000) 25:             { 26:                 _log.WarnFormat("Long query in GetAvailableProducts() took {0} ms", 27:                     timer.ElapsedMillseconds); 28:             } 29:             30:             return results; 31:         } 32:     } In my eye, this is very ugly.  It violates Single Responsibility Principle (SRP), which says that a class should only ever have one responsibility, where responsibility is often defined as a reason to change.  This class (and in particular this method) has two reasons to change: If the method of retrieving products changes. If the method of logging changes. Well, we could “simplify” this using the Decorator Design Pattern (here).  If we followed the pattern to the letter, we'd need to create a base decorator that implements the DAOs public interface and forwards to the wrapped instance.  So let's assume we break out the ProductDAO interface into IProductDAO using your refactoring tool of choice (Resharper is great for this). Now, ProductDao will implement IProductDao and get rid of all logging logic: 1:     public class ProductDao : IProductDao 2:     { 3:         // this reverts back to original version except for the interface added 4:     } 5:  And we create the base Decorator that also implements the interface and forwards all calls: 1:     public class ProductDaoDecorator : IProductDao 2:     { 3:         private readonly IProductDao _wrappedDao; 4:         5:         // constructor takes the dao to wrap 6:         public ProductDaoDecorator(IProductDao wrappedDao) 7:         { 8:             _wrappedDao = wrappedDao; 9:         } 10:         11:         ... 12:         13:         // and then all methods just forward their calls 14:         public IEnumerable<Product> GetAvailableProducts() 15:         { 16:             return _wrappedDao.GetAvailableProducts(); 17:         } 18:     } This defines our base decorator, then we can create decorators that add items of interest, and for any methods we don't decorate, we'll get the default behavior which just forwards the call to the wrapper in the base decorator: 1:     public class TimedThresholdProductDaoDecorator : ProductDaoDecorator 2:     { 3:         private static readonly ILog _log = LogManager.GetLogger(typeof(TimedThresholdProductDaoDecorator)); 4:         5:         public TimedThresholdProductDaoDecorator(IProductDao wrappedDao) : 6:             base(wrappedDao) 7:         { 8:         } 9:         10:         ... 11:         12:         public IEnumerable<Product> GetAvailableProducts() 13:         { 14:             var timer = Stopwatch.StartNew(); 15:             16:             var results = _wrapped.GetAvailableProducts(); 17:             18:             timer.Stop(); 19:             20:             if (timer.ElapsedMilliseconds > 5000) 21:             { 22:                 _log.WarnFormat("Long query in GetAvailableProducts() took {0} ms", 23:                     timer.ElapsedMillseconds); 24:             } 25:             26:             return results; 27:         } 28:     } Well, it's a bit better.  Now the logging is in its own class, and the database logic is in its own class.  But we've essentially multiplied the number of classes.  We now have 3 classes and one interface!  Now if you want to do that same logging decorating on all your DAOs, imagine the code bloat!  Sure, you can simplify and avoid creating the base decorator, or chuck it all and just inherit directly.  But regardless all of these have the problem of tying the logging logic into the code itself. Enter the Interceptors.  Things like this to me are a perfect example of when it's good to write an Interceptor using your class library of choice.  Sure, you could design your own perfectly generic decorator with delegates and all that, but personally I'm a big fan of Castle's Dynamic Proxy (here) which is actually used by many projects including Moq. What DynamicProxy allows you to do is intercept calls into any object by wrapping it with a proxy on the fly that intercepts the method and allows you to add functionality.  Essentially, the code would now look like this using DynamicProxy: 1: // Note: I like hiding DynamicProxy behind the scenes so users 2: // don't have to explicitly add reference to Castle's libraries. 3: public static class TimeThresholdInterceptor 4: { 5: // Our logging handle 6: private static readonly ILog _log = LogManager.GetLogger(typeof(TimeThresholdInterceptor)); 7:  8: // Handle to Castle's proxy generator 9: private static readonly ProxyGenerator _generator = new ProxyGenerator(); 10:  11: // generic form for those who prefer it 12: public static object Create<TInterface>(object target, TimeSpan threshold) 13: { 14: return Create(typeof(TInterface), target, threshold); 15: } 16:  17: // Form that uses type instead 18: public static object Create(Type interfaceType, object target, TimeSpan threshold) 19: { 20: return _generator.CreateInterfaceProxyWithTarget(interfaceType, target, 21: new TimedThreshold(threshold, level)); 22: } 23:  24: // The interceptor that is created to intercept the interface calls. 25: // Hidden as a private inner class so not exposing Castle libraries. 26: private class TimedThreshold : IInterceptor 27: { 28: // The threshold as a positive timespan that triggers a log message. 29: private readonly TimeSpan _threshold; 30:  31: // interceptor constructor 32: public TimedThreshold(TimeSpan threshold) 33: { 34: _threshold = threshold; 35: } 36:  37: // Intercept functor for each method invokation 38: public void Intercept(IInvocation invocation) 39: { 40: // time the method invocation 41: var timer = Stopwatch.StartNew(); 42:  43: // the Castle magic that tells the method to go ahead 44: invocation.Proceed(); 45:  46: timer.Stop(); 47:  48: // check if threshold is exceeded 49: if (timer.Elapsed > _threshold) 50: { 51: _log.WarnFormat("Long execution in {0} took {1} ms", 52: invocation.Method.Name, 53: timer.ElapsedMillseconds); 54: } 55: } 56: } 57: } Yes, it's a bit longer, but notice that: This class ONLY deals with logging long method calls, no DAO interface leftovers. This class can be used to time ANY class that has an interface or virtual methods. Personally, I like to wrap and hide the usage of DynamicProxy and IInterceptor so that anyone who uses this class doesn't need to know to add a Castle library reference.  As far as they are concerned, they're using my interceptor.  If I change to a new library if a better one comes along, they're insulated. Now, all we have to do to use this is to tell it to wrap our ProductDao and it does the rest: 1: // wraps a new ProductDao with a timing interceptor with a threshold of 5 seconds 2: IProductDao dao = TimeThresholdInterceptor.Create<IProductDao>(new ProductDao(), 5000); Automatic decoration of all methods!  You can even refine the proxy so that it only intercepts certain methods. This is ideal for so many things.  These are just some of the interceptors we've dreamed up and use: Log parameters and returns of methods to XML for auditing. Block invocations to methods and return default value (stubbing). Throw exception if certain methods are called (good for blocking access to deprecated methods). Log entrance and exit of a method and the duration. Log a message if a method takes more than a given time threshold to execute. Whether you use DynamicProxy or some other technology, I hope you see the benefits this adds.  Does it completely eliminate all need for the Decorator pattern?  No, there may still be cases where you want to decorate a particular class with functionality that doesn't apply to the world at large. But for all those cases where you are using Decorator to add functionality that's truly generic.  I strongly suggest you give this a try!

  Read the article

• Entourage Reminders for events not on calendar

  - by Jon Lasser

  After a series of nasty mishaps, I needed to create a new Entourage profile and re-populate my calendar by resynching it with my Exchange Server. Now I'm receiving multiple notifications for a single appointment -- two or even four at once. (Perhaps four is due to the intermediate 'reset' attempts I made before discarding and creating a new profile.) Reviewing my calendar I see only a single appointment, not multiple appointments. Checking my Outlook calendar confirms only a single appointment. My local calendar is completely empty. Is there a separate Entourage database for reminders that I can clear or resync? Is there somewhere else for calendar appointments to live where I'm not looking?

  Read the article

• Game Changer Appliance for SMBs Powered by Oracle Linux

  - by Zeynep Koch

  In the November 28th CRN article  Review: Thumbs-Up On Oracle Database Appliance  , Edward F. Moltzen mentions that "The Test Center likes this appliance (Oracle Database Appliance) , for the performance and for the strong security offered by the underlying Oracle Linux in the box. It’s more than a solid offering for the SMB space; it’s potentially a game-changer as data and security needs race to keep up with the oncoming generations of technology." The Oracle Database Appliance is a new way to take advantage of the world's most popular database—Oracle Database 11g—in a single, easy-to-deploy and manage system. It's a complete package of software, server, storage, and network that's engineered for simplicity; saving time and money by simplifying deployment, maintenance, and support of database workloads. All hardware and software components are supported by a single vendor—Oracle—and offer customers unique pay-as-you-grow software licensing to quickly scale from 2 processor cores to 24 processor cores without incurring the costs and downtime usually associated with hardware upgrades. It is: Simple—Complete plug-and-go hardware and software Reliable—Advanced management features and single-vendor support Affordable—Pay-as-you-grow platform for small database consolidation The Oracle Database Appliance is a 4U rack-mountable system pre-installed with Oracle Linux and Oracle appliance manager software. Redundancy is built into all components and the Oracle appliance manager software reduces the risk and complexity of deploying highly available databases. It's perfect for consolidating OLTP and data warehousing databases up to 4 terabytes in size, making it ideal for midsize companies or departmental systems. Read more about Oracle's Database Appliance  Read more about Oracle Linux

  Read the article

• Dryad and DryadLINQ from MSR

  - by Daniel Moth

  Microsoft Research (MSR) researches technologies, incubates projects which many times result in technology that looks like a ready-to-use product (but it is important to understand that these are not the same as products built by the various… actual product teams here at Microsoft). A very popular MSR project has been DryadLINQ, which itself builds on Dryad. To learn more follow the project pages I just linked to and I also recommend this 1-hour channel 9 video. If you only have 3 minutes, watch this great elevator pitch instead. You can also stay tuned on the official blog, which includes a post that refers to internal adoption e.g by Bing, a quick DryadLINQ code example, and some history on how DryadLINQ generalizes the MapReduce pattern and makes it accessible to regular programmers (see this post and that post). Essentially, the DryadLINQ framework (building on the Dryad runtime) allows developers to re-use their LINQ skills for creating/generating programs that process large multi-gigabyte/terabyte datasets across 100s-1000s of machines. One way to think about it is that just as Parallel LINQ allows LINQ developers to seamlessly use multiple cores from a single process on a single machine, DryadLINQ allows LINQ developers to seamlessly use multiple machines for their data parallel algorithms. In the former scenario the motivation was speed of execution, in the latter it is speed of execution AND processing large datasets that simply don't fit on a single machine. Whenever I hear about execution of parallel code on multiple machines on the Microsoft platform, I immediately think of Windows HPC Server. Indeed Dryad and DryadLINQ were made available for Windows HPC Server and I encourage you to watch the PDC session on this topic: Data-Intensive Computing on Windows HPC Server with the DryadLINQ Framework. Watch this space… Comments about this post welcome at the original blog.

  Read the article

• How do you create large, growable, shared filesystems on Linux at AWS?

  - by Reece

  What are acceptable/reasonable/best ways to provide large, growable, shared storage at AWS, exposed as a single filesystem? We're currently making 1TB EBS volumes ~biweekly and NFS exporting with no_subtree_check and nohide. In this setup, distinct exports appear under a single mount on the client. This arrangement does not scale well. The options we've considered: LVM2 with ext4. resize2fs is too slow. Btrfs on Linux. not obviously ready for prime time yet. ZFS on Linux. not obviously ready for prime time yet (although LLNL uses it) ZFS on Solaris. future of this combo is uncertain (to me), and new OS in the mix glusterfs. heard mostly good but two scary (and maybe old?) stories. The ideal solution would provide sharing, a single fs view, easy expandability, snapshots, and replication. Thanks for sharing ideas and experience.

  Read the article

• Is there a way communicate or measure levels of abstraction?

  - by hydroparadise

  I'll be the first to say that this question is a bit... out there. But here are a couple questions I bear in mind : Is abstraction continuous or discrete? Is there a single unit of abstraction? But I'm not sure those questions are truly answerable or even really makes sence. My naive answer would be something along the lines of abitrarily discrete but not necescarily having a single unit measure. Here's what I mean... Take a Black Labrador; an abstraction that could be made is that a Black Lab is a type of animal. [Animal]<--[Black Lab] A Black Lab is also a type of Dog. [Dog]<--[Black Lab] One way to establish a degree of abstraction is by comparing the two the abstractions. We could say that [Animal] is more abstract than [Dog] in respect to a Black Lab. It just so happens [Animal] can also be used as an abstraction of [Dog] So, we might end up with something like [Animal]<--[Dog]<--[Black Lab] With the model above, one might be inclined to say that there's two hops of abstraction to get from [Black Lab] to [Animal]. But you can't exactly tell somebody they need one level abstraction and reasonalby expect they will come up with [Dog] given they aren't explicity given the options above. If I needed to tell someobody in a single email that they needed an abstract class with out knowing what that abstract class is, is there a way to communaticate a degree of abstraction such that they might end up on Dog instead of Animal? As a side note, what area of study might this type of analysis fall under?

  Read the article

• Help with complex MVVM (multiple views)

  - by jsjslim

  I need help creating view models for the following scenario: Deep, hierarchical data Multiple views for the same set of data Each view is a single, dynamically-changing view, based on the active selection Depending on the value of a property, display different types of tabs in a tab control My questions: Should I create a view-model representation for each view (VM1, VM2, etc)? 1. Yes: a. Should I model the entire hierarchical relationship? (ie, SubVM1, HouseVM1, RoomVM1) b. How do I keep all hierarchies in sync? (e.g, adding/removing nodes) 2. No: a. Do I use a huge, single view model that caters for all views? Here's an example of a single view Figure 1: Multiple views updated based on active room. Notice Tab control Figure 2: Different active room. Multiple views updated. Tab control items changed based on object's property. Figure 3: Different selection type. Entire view changes

  Read the article

• shutdown -i all computers in active directory domain

  - by Sihan Zheng

  I'm not sure if this is possible, but this is my goal: At the end of the day, I want to be able to turn off all the computers in the domain from a client. My account has sufficient privileges to shutdown any single computer remotely using shutdown -I, and I can RDP into any computer in the domain. However, is there an automated technique that does this? the computers in the domain are predictably named (computer1, computer2, etc), but than manipulating a list of 2000 computers in shutdown -I is pretty clumsy. Is there a way to shutdown every single computer in the domain from a single client? The domain server is windows 2003, and the clients all run windows xp thanks

  Read the article

• Is there a name for a testing method where you compare a set of very different designs?

  - by DVK

  "A/B testing" is defined as "a method of marketing testing by which a baseline control sample is compared to a variety of single-variable test samples in order to improve response rates". The point here, of course, is to know which small single-variable changes are more optimal, with the goal of finding the local optimum. However, one can also envision a somewhat related but different scenario for testing the response rate of major re-designs: take a baseline control design, take one or more completely different designs, and run test samples on those redesigns to compare response rates. As a practical but contrived example, imagine testing a set of designs for the same website, one being minimalist "googly" design, one being cluttered "Amazony" design, and one being an artsy "designy" design (e.g. maximum use of design elements unlike Google but minimal simultaneously presented information, like Google but unlike Amazon) Is there an official name for such testing? It's definitely not A/B testing, since the main component of it (finding local optimum by testing single-variable small changes that can be attributed to response shift) is not present. This is more about trying to compare a set of local optimums, and compare to see which one works better as a global optimum. It's not a multivriable, A/B/N or any other such testing since you don't really have specific variables that can be attributed, just different designs.

  Read the article

• Code Reuse is (Damn) Hard

  - by James Michael Hare

  Being a development team lead, the task of interviewing new candidates was part of my job.  Like any typical interview, we started with some easy questions to get them warmed up and help calm their nerves before hitting the hard stuff. One of those easier questions was almost always: “Name some benefits of object-oriented development.”  Nearly every time, the candidate would chime in with a plethora of canned answers which typically included: “it helps ease code reuse.”  Of course, this is a gross oversimplification.  Tools only ease reuse, its developers that ultimately can cause code to be reusable or not, regardless of the language or methodology. But it did get me thinking…  we always used to say that as part of our mantra as to why Object-Oriented Programming was so great.  With polymorphism, inheritance, encapsulation, etc. we in essence set up the concepts to help facilitate reuse as much as possible.  And yes, as a developer now of many years, I unquestionably held that belief for ages before it really struck me how my views on reuse have jaded over the years.  In fact, in many ways Agile rightly eschews reuse as taking a backseat to developing what's needed for the here and now.  It used to be I was in complete opposition to that view, but more and more I've come to see the logic in it.  Too many times I've seen developers (myself included) get lost in design paralysis trying to come up with the perfect abstraction that would stand all time.  Nearly without fail, all of these pieces of code become obsolete in a matter of months or years. It’s not that I don’t like reuse – it’s just that reuse is hard.  In fact, reuse is DAMN hard.  Many times it is just a distraction that eats up architect and developer time, and worse yet can be counter-productive and force wrong decisions.  Now don’t get me wrong, I love the idea of reusable code when it makes sense.  These are in the few cases where you are designing something that is inherently reusable.  The problem is, most business-class code is inherently unfit for reuse! Furthermore, the code that is reusable will often fail to be reused if you don’t have the proper framework in place for effective reuse that includes standardized versioning, building, releasing, and documenting the components.  That should always be standard across the board when promoting reusable code.  All of this is hard, and it should only be done when you have code that is truly reusable or you will be exerting a large amount of development effort for very little bang for your buck. But my goal here is not to get into how to reuse (that is a topic unto itself) but what should be reused.  First, let’s look at an extension method.  There’s many times where I want to kick off a thread to handle a task, then when I want to reign that thread in of course I want to do a Join on it.  But what if I only want to wait a limited amount of time and then Abort?  Well, I could of course write that logic out by hand each time, but it seemed like a great extension method: 1: public static class ThreadExtensions 2: { 3: public static bool JoinOrAbort(this Thread thread, TimeSpan timeToWait) 4: { 5: bool isJoined = false; 6:  7: if (thread != null) 8: { 9: isJoined = thread.Join(timeToWait); 10:  11: if (!isJoined) 12: { 13: thread.Abort(); 14: } 15: } 16: return isJoined; 17: } 18: } 19:  When I look at this code, I can immediately see things that jump out at me as reasons why this code is very reusable.  Some of them are standard OO principles, and some are kind-of home grown litmus tests: Single Responsibility Principle (SRP) – The only reason this extension method need change is if the Thread class itself changes (one responsibility). Stable Dependencies Principle (SDP) – This method only depends on classes that are more stable than it is (System.Threading.Thread), and in itself is very stable, hence other classes may safely depend on it. It is also not dependent on any business domain, and thus isn't subject to changes as the business itself changes. Open-Closed Principle (OCP) – This class is inherently closed to change. Small and Stable Problem Domain – This method only cares about System.Threading.Thread. All-or-None Usage – A user of a reusable class should want the functionality of that class, not parts of that functionality.  That’s not to say they most use every method, but they shouldn’t be using a method just to get half of its result. Cost of Reuse vs. Cost to Recreate – since this class is highly stable and minimally complex, we can offer it up for reuse very cheaply by promoting it as “ready-to-go” and already unit tested (important!) and available through a standard release cycle (very important!). Okay, all seems good there, now lets look at an entity and DAO.  I don’t know about you all, but there have been times I’ve been in organizations that get the grand idea that all DAOs and entities should be standardized and shared.  While this may work for small or static organizations, it’s near ludicrous for anything large or volatile. 1: namespace Shared.Entities 2: { 3: public class Account 4: { 5: public int Id { get; set; } 6:  7: public string Name { get; set; } 8:  9: public Address HomeAddress { get; set; } 10:  11: public int Age { get; set;} 12:  13: public DateTime LastUsed { get; set; } 14:  15: // etc, etc, etc... 16: } 17: } 18:  19: ... 20:  21: namespace Shared.DataAccess 22: { 23: public class AccountDao 24: { 25: public Account FindAccount(int id) 26: { 27: // dao logic to query and return account 28: } 29:  30: ... 31:  32: } 33: } Now to be fair, I’m not saying there doesn’t exist an organization where some entites may be extremely static and unchanging.  But at best such entities and DAOs will be problematic cases of reuse.  Let’s examine those same tests: Single Responsibility Principle (SRP) – The reasons to change for these classes will be strongly dependent on what the definition of the account is which can change over time and may have multiple influences depending on the number of systems an account can cover. Stable Dependencies Principle (SDP) – This method depends on the data model beneath itself which also is largely dependent on the business definition of an account which can be very inherently unstable. Open-Closed Principle (OCP) – This class is not really closed for modification.  Every time the account definition may change, you’d need to modify this class. Small and Stable Problem Domain – The definition of an account is inherently unstable and in fact may be very large.  What if you are designing a system that aggregates account information from several sources? All-or-None Usage – What if your view of the account encompasses data from 3 different sources but you only care about one of those sources or one piece of data?  Should you have to take the hit of looking up all the other data?  On the other hand, should you have ten different methods returning portions of data in chunks people tend to ask for?  Neither is really a great solution. Cost of Reuse vs. Cost to Recreate – DAOs are really trivial to rewrite, and unless your definition of an account is EXTREMELY stable, the cost to promote, support, and release a reusable account entity and DAO are usually far higher than the cost to recreate as needed. It’s no accident that my case for reuse was a utility class and my case for non-reuse was an entity/DAO.  In general, the smaller and more stable an abstraction is, the higher its level of reuse.  When I became the lead of the Shared Components Committee at my workplace, one of the original goals we looked at satisfying was to find (or create), version, release, and promote a shared library of common utility classes, frameworks, and data access objects.  Now, of course, many of you will point to nHibernate and Entity for the latter, but we were looking at larger, macro collections of data that span multiple data sources of varying types (databases, web services, etc). As we got deeper and deeper in the details of how to manage and release these items, it quickly became apparent that while the case for reuse was typically a slam dunk for utilities and frameworks, the data access objects just didn’t “smell” right.  We ended up having session after session of design meetings to try and find the right way to share these data access components. When someone asked me why it was taking so long to iron out the shared entities, my response was quite simple, “Reuse is hard...”  And that’s when I realized, that while reuse is an awesome goal and we should strive to make code maintainable, often times you end up creating far more work for yourself than necessary by trying to force code to be reusable that inherently isn’t. Think about classes the times you’ve worked in a company where in the design session people fight over the best way to implement a class to make it maximally reusable, extensible, and any other buzzwordable.  Then think about how quickly that design became obsolete.  Many times I set out to do a project and think, “yes, this is the best design, I can extend it easily!” only to find out the business requirements change COMPLETELY in such a way that the design is rendered invalid.  Code, in general, tends to rust and age over time.  As such, writing reusable code can often be difficult and many times ends up being a futile exercise and worse yet, sometimes makes the code harder to maintain because it obfuscates the design in the name of extensibility or reusability. So what do I think are reusable components? Generic Utility classes – these tend to be small classes that assist in a task and have no business context whatsoever. Implementation Abstraction Frameworks – home-grown frameworks that try to isolate changes to third party products you may be depending on (like writing a messaging abstraction layer for publishing/subscribing that is independent of whether you use JMS, MSMQ, etc). Simplification and Uniformity Frameworks – To some extent this is similar to an abstraction framework, but there may be one chosen provider but a development shop mandate to perform certain complex items in a certain way.  Or, perhaps to simplify and dumb-down a complex task for the average developer (such as implementing a particular development-shop’s method of encryption). And what are less reusable? Application and Business Layers – tend to fluctuate a lot as requirements change and new features are added, so tend to be an unstable dependency.  May be reused across applications but also very volatile. Entities and Data Access Layers – these tend to be tuned to the scope of the application, so reusing them can be hard unless the abstract is very stable. So what’s the big lesson?  Reuse is hard.  In fact it’s damn hard.  And much of the time I’m not convinced we should focus too hard on it. If you’re designing a utility or framework, then by all means design it for reuse.  But you most also really set down a good versioning, release, and documentation process to maximize your chances.  For anything else, design it to be maintainable and extendable, but don’t waste the effort on reusability for something that most likely will be obsolete in a year or two anyway.

  Read the article

• HTTP Non-persistent connection and objects splitting

  - by Fabio Carello

  I hope this is the right board for my question about HTTP protocol with non-persistent connections. Suppose a single request for a html object that requires to be split in two different HTML response messages. My question is quite simple: do the connection will be closed after the first packet dispatch and then the other one will be sent on a new connection? I can't figure out if the non-persistent connection is applied at "single object level" (does't care if on multiples messages) or for every single message. Thanks for your answers!

  Read the article

• Recommend Online password manager [closed]

  - by Dmitriy Nagirnyak

  Possible Duplicate: online password manager with sharing capabilities Hi, I am looking for a good online password manager with the following requirements: Single click login from browser. Single click form saving from the browser. Not attached to a single PC. Offline version (so I can use it if there is no internet, for example plug USB and have last sync-ed data). Ability to store plain text (notes, for example). Should work on Windows, Linux and Mac. So far I have been happy with RoboForm, but its offline USB version is not available on Linux. Please recommend. Thanks, Dmitriy.

  Read the article

• Is rotating the lead developer a good or bad idea?

  - by Renesis

  I work on a team that has been flat organizationally since it's creation several months ago. My manager is non-technical and this means that our whole team is responsible for decision-making. My manager is beginning to realize that there are several benefits to having a lead developer, both for his sake (a single point of contact and single responsible party for tasks) and ours (dispute resolution, organized technical guidance, etc.). Because the team has been flat, one concern is that picking one lead developer may discourage the others. A non-developer suggested to my manager that rotating the lead developer is a possible way to avoid this issue. One developer would be lead one month, another the next, and so on. Is this a good idea? Why or why not? Keep in mind that this means all developers — All developers are good, but not necessarily equally suited to leadership. And if it is not, suppose I am likely the best candidate for lead developer — how do I recommend that we avoid this approach without looking like it's merely for selfish reasons? (In other words, the team is small enough that anyone recommending a single leader is likely to appear to be recommending themselves — especially those who have been part of the team longer.)

  Read the article

• Critical Patch Update For Oracle Fusion Middleware - CPU October 2012

  - by Daniel Mortimer

  The latest Critical Patch Update (CPU) has been released for Oracle products. Start your reading hereCritical Patch Updates, Security Alerts and Third Party Bulletin  This is the home page containing links to all "Critical Patch Updates" released to date, along with sections detailing  Security Alerts  Third Party Bulletin Public Vulnerabilities Fixed Policies Reporting Security Vulnerabilities  On this page you will find the link to the Oracle Critical Patch Update Advisory - October 2012 The advisory lists the support documents that cover the patch availability for all Oracle products. From an Oracle Fusion Middleware perspective, you can cut to the chase by using the links below which take you to the appropriate sections inPatch Set Update and Critical Patch Update October 2012 Availability Document [ID 1477727.1] Oracle Fusion Middleware 11g Release 2  11.1.2.0 Oracle Fusion Middleware 11g Release 1 11.1.1.4 (Portal,Forms,Reports and Discoverer) 11.1.1.5 11.1.1.6 Oracle Application Server 10g Release 3 10.1.3.5 The #anchor links above should work in Firefox and IE provided you have already logged into My Oracle Support within the same browser session. For some reason, Chrome always takes you to the top of the document :-/ Tip: Error Correction Support for Oracle Identity Management 10g, version 10.1.4.x ended in December 2011. For this reason, there is no section which is specific to this version. However, Error Correction Support remains in place, until end of this year, for the Oracle Identity Management 10.1.4.x components Single Sign On (SSO) Delegated Administration Services (OIDDAS) provided you are using them as part of a Single Sign-On solution (OID 11g + SSO / OIDDAS 10.1.4.3) for a Portal / Forms / Reports and Discoverer 11.1.1.x architecture.    As such there are security related patches available for Fusion Middleware Single Sign On. You will find the patch numbers listed in the sections for 11.1.1.4, 11.1.1.5 and 11.1.1.6 And finally, if you are hit any unexpected errors when applying the CPU patches, check out the known issues documented in these two support documents. Critical Patch Update October 2012 Oracle Fusion Middleware Known Issues (Doc ID 1455408.1) Critical Patch Update October 2012 Database Known Issues (Doc ID 1477865.1)

  Read the article

• What's New in Database Lifecycle Management in Enterprise Manager 12c Release 3

  - by HariSrinivasan

  Enterprise Manager 12c Release 3 includes improvements and enhancements across every area of the product. This blog provides an overview of the new and enhanced features in the Database Lifecycle Management area. I will deep dive into specific features more in depth in subsequent posts. "What's New?"  In this release, we focused on four things: 1. Lifecycle Management Support for new Database12c - Pluggable Databases 2. Management of long running processes, such as a security patch cycle (Change Activity Planner) 3. Management of large number of systems by · Leveraging new framework capabilities for lifecycle operations, such as the new advanced ‘emcli’ script option · Refining features such as configuration search and compliance 4. Minor improvements and quality fixes to existing features · Rollback support for Single instance databases · Improved "OFFLINE" Patching experience · Faster collection of ORACLE_HOME configurations Lifecycle Management Support for new Database 12c - Pluggable Databases Database 12c introduces Pluggable Databases (PDBs), the brand new addition to help you achieve your consolidation goals. Pluggable databases offer unprecedented consolidation at database level and native lifecycle verbs for creating, plugging and unplugging the databases on a container database (CDB). Enterprise Manager can supplement the capabilities of pluggable databases by offering workflows for migrating, provisioning and cloning them using the software library and the deployment procedures. For example, Enterprise Manager can migrate an existing database to a PDB or clone a PDB by storing a versioned copy in the software library. One can also manage the planned downtime related to patching by  migrating the PDBs to a new CDB. While pluggable databases offer these exciting features, it can also pose configuration management and compliance challenges if not managed properly. Enterprise Manager features like inventory management, topology associations and configuration search can mitigate the sprawl of PDBs and also lock them to predefined golden standards using configuration comparison and compliance rules. Learn More ... Management of Long Running datacenter processes - Change Activity Planner (CAP) Currently, customers resort to cumbersome methods to create, execute, track and monitor change activities within their data center. Some customers use traditional tools such as spreadsheets, project planners and in-house custom built solutions. Customers often have weekly sync up meetings across stake holders to collect status and updates. Some of the change activities, for example the quarterly patch set update (PSU) patch rollouts are not single tasks but processes with multiple tasks. Some of those tasks are performed within Enterprise Manager Cloud Control (for example Patch) and some are performed outside of Enterprise Manager Cloud Control. These tasks often run for a longer period of time and involve multiple people or teams. Enterprise Manger Cloud Control supports core data center operations such as configuration management, compliance management, and automation. Enterprise Manager Cloud Control release 12.1.0.3 leverages these capabilities and introduces the Change Activity Planner (CAP). CAP provides the ability to plan, execute, and track change activities in real time. It covers the typical datacenter activities that are spread over a long period of time, across multiple people and multiple targets (even target types). Here are some examples of Change Activity Process in a datacenter: · Patching large environments (PSU/CPU Patching cycles) · Upgrading large number of database environments · Rolling out Compliance Rules · Database Consolidation to Exadata environments CAP provides user flows for Compliance Officers/Managers (incl. lead administrators) and Operators (DBAs and admins). Managers can create change activity plans for various projects, allocate resources, targets, and groups affected. Upon activation of the plan, tasks are created and automatically assigned to individual administrators based on target ownership. Administrators (DBAs) can identify their tasks and understand the context, schedules, and priorities. They can complete tasks using Enterprise Manager Cloud Control automation features such as patch plans (or in some cases outside Enterprise Manager). Upon completion, compliance is evaluated for validations and updates the status of the tasks and the plans. Learn More about CAP ...  Improved Configuration & Compliance Management of a large number of systems Improved Configuration Comparison:  Get to the configuration comparison results faster for simple ad-hoc comparisons. When performing a 1 to 1 comparison, Enterprise Manager will perform the comparison immediately and take the user directly to the results without having to wait for a job to be submitted and executed. Flattened system comparisons reduce comparison setup time and reduce complexity. In addition to the previously existing topological comparison, users now have an option to compare using a “flattened” methodology. Flattening means to remove duplicate target instances within the systems and remove the hierarchy of member targets. The result are much easier to spot differences particularly for specific use cases like comparing patch levels between complex systems like RAC and Fusion Apps. Improved Configuration Search & Advanced EMCLI Script option for Mass Automation Enterprise manager 12c introduces a new framework level capability to be able to script and stitch together multiple tasks using EMCLI. This powerful capability can be leveraged for lifecycle operations, especially when executing a task over a large number of targets. Specific usages of this include, retrieving a qualified list of targets using Configuration Search and then using the resultset for automation. Another example would be executing a patching operation and then re-executing on targets where it may have failed. This is complemented by other enhancements, such as a better usability for designing reusable configuration searches. IN EM 12c Rel 3, a simplified UI makes building adhoc searches even easier. Searching for missing patches is a common use of configuration search. This required the use of the advanced options which are now clearly defined and easy to use. Perform “Configuration Search” using the EMCLI. Users can find and execute Configuration Searches from the EMCLI which can be extremely useful for building sophisticated automation scripts. For an example, Run the Search named “Oracle Databases on Exadata” which finds all Database targets running on top of Exadata. Further filter the results by refining by options like name, host, etc.. emcli get_targets -config_search="Databases on Exadata" –target_name="exa%“ Use this in powerful mass automation operations using the new emcli script option. For example, to solve the use case of – Finding all DBs running on Exadata and housing E-Biz and Patch them. Create a Python script with emcli functions and invoke it in the new EMCLI script option shell. Invoke the script in the new EMCLI with script option directly: $<path to emcli>/emcli @myPSU_Patch.py Richer compliance content:  Now over 50 Oracle Provided Compliance Standards including new standards for Pluggable Database, Fusion Applications, Oracle Identity Manager, Oracle VM and Internet Directory. 9 Oracle provided Real Time Monitoring Standards containing over 900 Compliance Rules across 500 Facets. These new Real time Compliance Standards covers both Exadata Compute nodes and Linux servers. The result is increased Oracle software coverage and faster time to compliance monitoring on Exadata. Enhancements to Patch Management: Overhauled "OFFLINE" Patching experience: Simplified Patch uploads UI to improve the offline experience of patching. There is now a single step process to get the patches into software library. Customers often maintain local repositories of patches, sometimes called software depots, where they host the patches downloaded from My Oracle Support. In the past, you had to move these patches to your desktop then upload them to the Enterprise Manager's Software library through the Enterprise Manager Cloud Control user interface. You can now use the following EMCLI command to upload multiple patches directly from a remote location within the data center: $emcli upload_patches -location <Path to Patch directory> -from_host <HOSTNAME> The upload process filters all of the new patches, automatically selects the relevant metadata files from the location, and uploads the patches to software library. Other Improvements:  Patch rollback for single instance databases, new option in the Patch Plan to rollback the patches added to the patch plans. Upon execution, the procedure would rollback the patch and the SQL applied to the single instance Databases. Improved and faster configuration collection of Oracle Home targets can enable more reliable automation at higher level functions like Provisioning, Patching or Database as a Service. Just to recap, here is a list of database lifecycle management features:  * Red highlights mark – New or Enhanced in the Release 3. • Discovery, inventory tracking and reporting • Database provisioning including o Migration to Pluggable databases o Plugging and unplugging of pluggable databases o Gold image based cloning o Scaling of RAC nodes •Schema and data change management •End-to-end patch management in online and offline modes, including o Patch advisories in online (connected with My Oracle Support) and offline mode o Patch pre-deployment analysis, deployment and rollback (currently only for single instance databases) o Reporting • Upgrade planning and execution of the upgrade process • Configuration management including • Compliance management with out-of-box content • Change Activity Planner for planning, designing and tracking long running processes For more information on Enterprise Manager’s database lifecycle management capabilities, visit http://www.oracle.com/technetwork/oem/lifecycle-mgmt/index.html

  Read the article

• Styles of games that work at low-resolution

  - by Brendan Long

  I'm taking a class on compilers, and the goal is to write a compiler for Meggy Jr devices (Arduino). The goal is just to make a simple compilers with loops and variables and stuff. Obviously, that's lame, so the "real goal" is to make an impressive game on the device. The problem is that it only has 64 pixels to work with (technically 72, but the top 8 are single-color and not part of the main display, so they're really only useful for displaying things like money). My problem is thinking of something to do on a device that small. It doesn't really matter if it's original, but it can't be something that's already available. My first idea was "snake", but that comes with the SDK. Same with a side-scrolling shooter. Remaining ideas include a tower defense game (hard to write, hard to control), an RPG (same), tetris (lame).. The problem is that all of the games I like require a high-resolution screen because they have a lot of text. Even a really simple game like nethack would be hard because each creature would be a single color. tl;dr What styles of games require a. No text; and b. Few enough objects that representing them each with a single color is acceptable? EDIT: To clarify, the display is 8x8 for a total of 64 pixels, not 64x64.

  Read the article

• Styles of games that work at low-resolution

  - by Brendan Long

  I'm taking a class on compilers, and the goal is to write a compiler for Meggy Jr devices (Arduino). The goal is just to make a simple compilers with loops and variables and stuff. Obviously, that's lame, so the "real goal" is to make an impressive game on the device. The problem is that it only has 64 pixels to work with (technically 72, but the top 8 are single-color and not part of the main display, so they're really only useful for displaying things like money). My problem is thinking of something to do on a device that small. It doesn't really matter if it's original, but it can't be something that's already available. My first idea was "snake", but that comes with the SDK. Same with a side-scrolling shooter. Remaining ideas include a tower defense game (hard to write, hard to control), an RPG (same), tetris (lame).. The problem is that all of the games I like require a high-resolution screen because they have a lot of text. Even a really simple game like nethack would be hard because each creature would be a single color. tl;dr What styles of games require a. No text; and b. Few enough objects that representing them each with a single color is acceptable?

  Read the article

• Solving Big Problems with Oracle R Enterprise, Part II

  - by dbayard

  Part II – Solving Big Problems with Oracle R Enterprise In the first post in this series (see https://blogs.oracle.com/R/entry/solving_big_problems_with_oracle), we showed how you can use R to perform historical rate of return calculations against investment data sourced from a spreadsheet.  We demonstrated the calculations against sample data for a small set of accounts.  While this worked fine, in the real-world the problem is much bigger because the amount of data is much bigger.  So much bigger that our approach in the previous post won’t scale to meet the real-world needs. From our previous post, here are the challenges we need to conquer: The actual data that needs to be used lives in a database, not in a spreadsheet The actual data is much, much bigger- too big to fit into the normal R memory space and too big to want to move across the network The overall process needs to run fast- much faster than a single processor The actual data needs to be kept secured- another reason to not want to move it from the database and across the network And the process of calculating the IRR needs to be integrated together with other database ETL activities, so that IRR’s can be calculated as part of the data warehouse refresh processes In this post, we will show how we moved from sample data environment to working with full-scale data.  This post is based on actual work we did for a financial services customer during a recent proof-of-concept. Getting started with the Database At this point, we have some sample data and our IRR function.  We were at a similar point in our customer proof-of-concept exercise- we had sample data but we did not have the full customer data yet.  So our database was empty.  But, this was easily rectified by leveraging the transparency features of Oracle R Enterprise (see https://blogs.oracle.com/R/entry/analyzing_big_data_using_the).  The following code shows how we took our sample data SimpleMWRRData and easily turned it into a new Oracle database table called IRR_DATA via ore.create().  The code also shows how we can access the database table IRR_DATA as if it was a normal R data.frame named IRR_DATA. If we go to sql*plus, we can also check out our new IRR_DATA table: At this point, we now have our sample data loaded in the database as a normal Oracle table called IRR_DATA.  So, we now proceeded to test our R function working with database data. As our first test, we retrieved the data from a single account from the IRR_DATA table, pull it into local R memory, then call our IRR function.  This worked.  No SQL coding required! Going from Crawling to Walking Now that we have shown using our R code with database-resident data for a single account, we wanted to experiment with doing this for multiple accounts.  In other words, we wanted to implement the split-apply-combine technique we discussed in our first post in this series.  Fortunately, Oracle R Enterprise provides a very scalable way to do this with a function called ore.groupApply().  You can read more about ore.groupApply() here: https://blogs.oracle.com/R/entry/analyzing_big_data_using_the1 Here is an example of how we ask ORE to take our IRR_DATA table in the database, split it by the ACCOUNT column, apply a function that calls our SimpleMWRR() calculation, and then combine the results. (If you are following along at home, be sure to have installed our myIRR package on your database server via  “R CMD INSTALL myIRR”). The interesting thing about ore.groupApply is that the calculation is not actually performed in my desktop R environment from which I am running.  What actually happens is that ore.groupApply uses the Oracle database to perform the work.  And the Oracle database is what actually splits the IRR_DATA table by ACCOUNT.  Then the Oracle database takes the data for each account and sends it to an embedded R engine running on the database server to apply our R function.  Then the Oracle database combines all the individual results from the calls to the R function. This is significant because now the embedded R engine only needs to deal with the data for a single account at a time.  Regardless of whether we have 20 accounts or 1 million accounts or more, the R engine that performs the calculation does not care.  Given that normal R has a finite amount of memory to hold data, the ore.groupApply approach overcomes the R memory scalability problem since we only need to fit the data from a single account in R memory (not all of the data for all of the accounts). Additionally, the IRR_DATA does not need to be sent from the database to my desktop R program.  Even though I am invoking ore.groupApply from my desktop R program, because the actual SimpleMWRR calculation is run by the embedded R engine on the database server, the IRR_DATA does not need to leave the database server- this is both a performance benefit because network transmission of large amounts of data take time and a security benefit because it is harder to protect private data once you start shipping around your intranet. Another benefit, which we will discuss in a few paragraphs, is the ability to leverage Oracle database parallelism to run these calculations for dozens of accounts at once. From Walking to Running ore.groupApply is rather nice, but it still has the drawback that I run this from a desktop R instance.  This is not ideal for integrating into typical operational processes like nightly data warehouse refreshes or monthly statement generation.  But, this is not an issue for ORE.  Oracle R Enterprise lets us run this from the database using regular SQL, which is easily integrated into standard operations.  That is extremely exciting and the way we actually did these calculations in the customer proof. As part of Oracle R Enterprise, it provides a SQL equivalent to ore.groupApply which it refers to as “rqGroupEval”.  To use rqGroupEval via SQL, there is a bit of simple setup needed.  Basically, the Oracle Database needs to know the structure of the input table and the grouping column, which we are able to define using the database’s pipeline table function mechanisms. Here is the setup script: At this point, our initial setup of rqGroupEval is done for the IRR_DATA table.  The next step is to define our R function to the database.  We do that via a call to ORE’s rqScriptCreate. Now we can test it.  The SQL you use to run rqGroupEval uses the Oracle database pipeline table function syntax.  The first argument to irr_dataGroupEval is a cursor defining our input.  You can add additional where clauses and subqueries to this cursor as appropriate.  The second argument is any additional inputs to the R function.  The third argument is the text of a dummy select statement.  The dummy select statement is used by the database to identify the columns and datatypes to expect the R function to return.  The fourth argument is the column of the input table to split/group by.  The final argument is the name of the R function as you defined it when you called rqScriptCreate(). The Real-World Results In our real customer proof-of-concept, we had more sophisticated calculation requirements than shown in this simplified blog example.  For instance, we had to perform the rate of return calculations for 5 separate time periods, so the R code was enhanced to do so.  In addition, some accounts needed a time-weighted rate of return to be calculated, so we extended our approach and added an R function to do that.  And finally, there were also a few more real-world data irregularities that we needed to account for, so we added logic to our R functions to deal with those exceptions.  For the full-scale customer test, we loaded the customer data onto a Half-Rack Exadata X2-2 Database Machine.  As our half-rack had 48 physical cores (and 96 threads if you consider hyperthreading), we wanted to take advantage of that CPU horsepower to speed up our calculations.  To do so with ORE, it is as simple as leveraging the Oracle Database Parallel Query features.  Let’s look at the SQL used in the customer proof: Notice that we use a parallel hint on the cursor that is the input to our rqGroupEval function.  That is all we need to do to enable Oracle to use parallel R engines. Here are a few screenshots of what this SQL looked like in the Real-Time SQL Monitor when we ran this during the proof of concept (hint: you might need to right-click on these images to be able to view the images full-screen to see the entire image): From the above, you can notice a few things (numbers 1 thru 5 below correspond with highlighted numbers on the images above.  You may need to right click on the above images and view the images full-screen to see the entire image): The SQL completed in 110 seconds (1.8minutes) We calculated rate of returns for 5 time periods for each of 911k accounts (the number of actual rows returned by the IRRSTAGEGROUPEVAL operation) We accessed 103m rows of detailed cash flow/market value data (the number of actual rows returned by the IRR_STAGE2 operation) We ran with 72 degrees of parallelism spread across 4 database servers Most of our 110seconds was spent in the “External Procedure call” event On average, we performed 8,200 executions of our R function per second (110s/911k accounts) On average, each execution was passed 110 rows of data (103m detail rows/911k accounts) On average, we did 41,000 single time period rate of return calculations per second (each of the 8,200 executions of our R function did rate of return calculations for 5 time periods) On average, we processed over 900,000 rows of database data in R per second (103m detail rows/110s) R + Oracle R Enterprise: Best of R + Best of Oracle Database This blog post series started by describing a real customer problem: how to perform a lot of calculations on a lot of data in a short period of time.  While standard R proved to be a very good fit for writing the necessary calculations, the challenge of working with a lot of data in a short period of time remained. This blog post series showed how Oracle R Enterprise enables R to be used in conjunction with the Oracle Database to overcome the data volume and performance issues (as well as simplifying the operations and security issues).  It also showed that we could calculate 5 time periods of rate of returns for almost a million individual accounts in less than 2 minutes. In a future post, we will take the same R function and show how Oracle R Connector for Hadoop can be used in the Hadoop world.  In that next post, instead of having our data in an Oracle database, our data will live in Hadoop and we will how to use the Oracle R Connector for Hadoop and other Oracle Big Data Connectors to move data between Hadoop, R, and the Oracle Database easily.

  Read the article

• Audigy 2 Coaxial to Coaxial/Optical connection possible?

  - by Chris

  Hello, The original question is deleted, and asked again below with accurate information. Edit: Excuse me for my ignorance, my friend has a Logitech Z-5500 set. I thought after comparing those systems on Google images that he had the Z-680, but he hasn't. This set has a single Digital coaxial for DVD or CD players or PC sound cards (requires coaxial cable, sold separately) cable. This single cable was connected to the orange tulip connector (SPDIF coaxial out) on the backside of his onboard HP Elite m9070, this connector is broken. How can I use the digital out with a single cable coaxial cable on the Audigy2 (see image below) (I have the following converters for my disposal, can I use one of these? 3.5 mm male - coax optical mini optical male - toslink optical female 2 x toslink optical female, toslink coupler, optical audio extension note: Is it possible to connect a toslink cable with an mini optical male - toslink converter on the digital out of the Audigy 2? (see image below)

  Read the article

• iSCSI - what's faster?

  - by Unplugme71

  I have a DroboPro that is currently connected to a GS748TS switch. Also connected to the switch is a server and few workstations. Which method would be better in performance? Add a NIC to the server. Direct connect the DroboPro via iSCSI to the new NIC. Add a NIC to the server. Create a dedicated VLAN for the new NIC and Drobo. Add a NIC to the server and attach it to a separate switch. DroboPro connects to the switch. Becomes a private network, similar to a VLAN. DroboPro has a single ethernet connection. Server has a single ethernet connection (currently). Workstations each have a single ethernet connection.

  Read the article

• Just one client bound to address and port: does it make a difference broadcast versus unicast in terms of overhead?

  - by chrisapotek

  Scenario: I am implementing failed over for a network node, so my idea is to make the master node listens on a broadcast ip address and port. If the master node fails, another failover node will start listening on this broadcast address (and port) and take over. Question: My concern is that I will be using a broadcast IP address just for a single node: the master. The failover node only binds if the master fails, in other words, almost never. In terms of network/traffic overhead, is it bad to talk to a single node through a broadcast address or the network somehow is smart enough to know that nobody else is listening to this broadcast address and kind of treat it as a unicast in terms of overhead? My concern is that I will be flooding my network with packets from this broadcast address even thought I am just really talking to a single node (the master). But I can't use unicast because the failover node has to be able to pick up the master stream quickly and transparently in case it fails.

  Read the article

< Previous Page | 88 89 90 91 92 93 94 95 96 97 98 99  | Next Page >