Search Results

Search found 9017 results on 361 pages for 'efficient storage'.

Page 120/361 | < Previous Page | 116 117 118 119 120 121 122 123 124 125 126 127  | Next Page >

  • Updated Release of Windows Azure Service Management Cmdlets Now Available

    - by kaleidoscope
    An updated release of the Windows Azure Service Management (WASM) Cmdlets for PowerShell is now available. These cmdlets enable developers to effectively automate and manage all services in Windows Azure such as: Deploy new Hosted Services Upgrade your Services Remove your Hosted Services Manage your Storage accounts Manage your Certificates Configure your Diagnostics Transfer your Diagnostics Information More details can be found at http://blogs.msdn.com/windowsazure/   Anish

    Read the article

  • Sesame update du jour: SL 4, OOB, Azure, and proxy support

    - by Fabrice Marguerie
    I've just published a new version of Sesame Data Browser. Here's what's new this time: Upgraded to Silverlight 4 Can run out-of-browser (OOB), with elevated permissions. This gives you an icon on your desktop and enables new scenarios. Note: The application is unsigned for the moment. Support for Windows Azure authentication Support for SQL Azure authentication If you are behind a proxy that requires authentication, just give Sesame a new try after clicking on "If you are behind a proxy that requires authentication, please click here" An icon and a button for closing connections are now displayed on connection tabsSome less visible improvements Here is the connection view with anonymous access: If you want to access Windows Azure tables as OData, all you have to do is use your table storage endpoint as the URL, and provide your access key: A Windows Azure table storage address looks like this: http://<your account>.table.core.windows.net/ If you want to browse your SQL Azure databases with Sesame, you have to enable OData support for them at https://www.sqlazurelabs.com/ConfigOData.aspx. I won't show how it works because it's already been done in several places over the Web. Here are pointers: OData.org: Got SQL Azure? Then you've got OData OakLeaf Systems: Enabling and Using the OData Protocol with SQL Azure Patrick Verbruggen: Creating an OData feed for your Azure databases Shawn Wildermuth: SQL Azure's OData Support Jack Greenfield: How to Use OData for SQL Azure with AppFabric Access Control You can choose to enable anonymous access or not. When you don't enable anonymous access, you have to provide an Issuer name and a Secret key, and optionally an Security Token Service (STS) endpoint: Excerpt from Jack Greenfield's blog: To enable OData access to the currently selected database, check the box labeled "Enable OData". When OData access is enabled, database user mapping information is displayed at the bottom of the form.Use the drop down list labeled "Anonymous Access User" to select an anonymous access user. If an anonymous access user is selected, then all queries against the database presented without credentials will execute by impersonating that user. You can access the database as the anonymous user by clicking on the link provided at the bottom of the page. If no anonymous access user is selected, then the OData Service will not allow anonymous access to the database.Click the link labeled "Add User" to add a user for authenticated access. In the pop up panel, select the user from the drop down list. Leave the issuer name empty for simple authentication, or provide the name of a trusted Security Token Service (STS) for federated authentication. For example, to federate with another ACS based STS, provide the base URI for the STS endpoint displayed by the Windows Azure AppFabric Portal for the STS.Click the "OK" button to complete the configuration process and dismiss the pop up panel. When one or more authenticated access users are added, the OData Service will impersonate them when appropriate credentials are presented. You can designate as many authenticated access users as you like. The OData Service will decide which one to impersonate for each query by inspecting the credentials presented with the query.Next time I'll give an overview of how Sesame Data Browser is built.In the meantime, happy data browsing!

    Read the article

  • Backup Azure Tables, schedule Azure scripts&hellip; and more

    - by Herve Roggero
    Well – months of effort are now officially over… or should I say it’s just the beginning?   Enzo Cloud Backup 2.0 (beta) is now officially out!!! This tool will let you do the following: * Backup SQL Database (and SQL Server to a limited extend) * Backup Azure Tables * Restore SQL Backups into another SQL environment * Restore Azure Tables in Azure Storage, or SQL Environment * Manage and schedule database maintenance scripts * Drop database schema containers (with preview) for SaaS environments * Receive alerts (SMTP) when operations complete or fail That’s it at a high level… but you need to see the flexibility around these features. For example you can select a specific backup strategy for Azure Tables allowing faster backup operations when partition keys use GUIDs. You can also call custom stored procedures during the restore operation of Azure Tables, allowing you to transform the data along the way. You can also set a performance threshold during Azure Table backup operations to help you control possible throttling conditions in your Storage Account. Regarding database scripts, you can now define T-SQL scripts and schedule them for execution in a specific order. You can also tell Enzo to execute a pre and post script during Azure Table restore operations against a SQL environment. The backup operation now supports backing up to multiple devices at the same time. So you can execute a backup request to both a local file, and a blob at the same time, guaranteeing that both will contain the exact same data. And due to the level of options that are available, you can save backup definitions for later reuse. The screenshot below backs up Azure Tables to two devices (a blob and a SQL Database). You can also manage your database schemas for SaaS environments that use schema containers to separate customer data. This new edition allows you to see how many objects you have in each schema, backup specific schemas, and even drop all objects in a given schema. For example the screenshot below shows that the EnzoLog database has 4 user-defined schemas, and the AFA schema has 5 tables and 1 module (stored proc, function, view…). Selecting the AFA schema and trying to delete it will prompt another screen to show which objects will be deleted. As you can see, Enzo Cloud Backup provides amazing capabilities that can help you safeguard your data in SQL Database and Azure Tables, and give you advanced management functions for your Azure environment. Download a free trial today at http://www.bluesyntax.net.

    Read the article

  • mysql completely removing

    - by Dmitry Teplyakov
    I broke my mysql and now I want to completely reinstall it. I tried: $ sudo apt-get install --reinstall mysql-server $ sudo apt-get remove --purge mysql-client mysql-server But always I see popup with proposal to change root password, I change it and got an error that I can change it.. $ sudo apt-get remove --purge mysql-client mysql-server Reading package lists... Done Building dependency tree Reading state information... Done Package mysql-client is not installed, so not removed Package mysql-server is not installed, so not removed The following packages were automatically installed and are no longer required: libmygpo-qt1 libqtscript4-network libqtscript4-gui libtag-extras1 libqtscript4-sql libqtscript4-xml amarok-utils amarok-common libqtscript4-uitools liblastfm0 libloudmouth1-0 libqtscript4-core Use 'apt-get autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Setting up mysql-server-5.5 (5.5.28-0ubuntu0.12.04.2) ... 121114 19:04:03 [Note] Plugin 'FEDERATED' is disabled. 121114 19:04:03 InnoDB: The InnoDB memory heap is disabled 121114 19:04:03 InnoDB: Mutexes and rw_locks use GCC atomic builtins 121114 19:04:03 InnoDB: Compressed tables use zlib 1.2.3.4 121114 19:04:03 InnoDB: Initializing buffer pool, size = 128.0M 121114 19:04:03 InnoDB: Completed initialization of buffer pool InnoDB: Error: auto-extending data file ./ibdata1 is of a different size InnoDB: 0 pages (rounded down to MB) than specified in the .cnf file: InnoDB: initial 640 pages, max 0 (relevant if non-zero) pages! 121114 19:04:03 InnoDB: Could not open or create data files. 121114 19:04:03 InnoDB: If you tried to add new data files, and it failed here, 121114 19:04:03 InnoDB: you should now edit innodb_data_file_path in my.cnf back 121114 19:04:03 InnoDB: to what it was, and remove the new ibdata files InnoDB created 121114 19:04:03 InnoDB: in this failed attempt. InnoDB only wrote those files full of 121114 19:04:03 InnoDB: zeros, but did not yet use them in any way. But be careful: do not 121114 19:04:03 InnoDB: remove old data files which contain your precious data! 121114 19:04:03 [ERROR] Plugin 'InnoDB' init function returned error. 121114 19:04:03 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 121114 19:04:03 [ERROR] Unknown/unsupported storage engine: InnoDB 121114 19:04:03 [ERROR] Aborting 121114 19:04:03 [Note] /usr/sbin/mysqld: Shutdown complete start: Job failed to start invoke-rc.d: initscript mysql, action "start" failed. dpkg: error processing mysql-server-5.5 (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: mysql-server-5.5 E: Sub-process /usr/bin/dpkg returned an error code (1) It is good for me that I have not any important databases, but..

    Read the article

  • Silverlight Cream for June 06, 2010 -- #876

    - by Dave Campbell
    In this Issue: Brian Genisio, Michael Washington, Fons Sonnemans , Don Burnett, Xianzhong Zhu, Mike Snow, Jesse Liberty, Victor Gaudioso, David Kelley(-2-), and Matias Bonaventura . Shoutout: Anoop has a good post up: MEF or Managed Extensibility Framework and Lazy – Being Lazy with MEF, Custom Export Attributes etc Jesse Liberty's got a good post up if you are just Getting Started With Silverlight: A Path Through The Learning Material John Papa reports Updates and New Home for Sticky Plugin Tim Heuer announced Silverlight 4 Theme refresh including RIA Services templates From SilverlightCream.com: Adventures in MVVM – ViewModel Location and Creation Brian Genisio has a post up about ViewModels and how he attaches them to his views. Some discssion of MVVMLight, and other external links plus the code for the project. Simplified MEF: Dynamically Loading a Silverlight .xap Michael Washington has a good tutorial up on MEF, Silverlight, and ViewModel. In Michael's words: The goal here is to give you a quick easy win. You will be able to understand this one. You will come away with something you can use, and you will be able to tell your fellow colleagues, "MEF? yeah I'm using that, good stuff Touch Gesture Triggers for Windows Phone 7 projects in Blend 4.0 Fons Sonnemans has a post up about touch gestures for WP7 -- he's got 3 of them implemented using triggers, plus an external link to another, and the source. What the Heck is “MEF” for, and what Silverlight designers need to know about it? Don Burnett is also talking MEF... he does a good job of introducing MEF if you're not acquainted yet, plus some external information. Write Your Custom Effect Components in Silverlight 3 Xianzhong Zhu has a post up walking you through creating your own Custom Effect for Blend and Silverlight 3 ... lots of external links and the source project. Silverlight Tip of the Day #28 – Text Trimming Mike Snow's Tip #28 is about Text Trimming... what it does, and how it differs from WPF Windows Phone 7: Lists, Page Animation and oData Jesse Liberty called this a mini-tutorial, but it's not so mini... great tutorial on WP7, data, lists, and page transitions... oh, and the data is OData too... New Silveright Video Tutorial: How to Do Hit Detection Victor Gaudioso's latest video tutorial is up and he's demonstrating how to do Silverlight HitTesting via code from Andy Beaulieu Dependency Properties Made Easy Need a quick pick-up on Dependency Properties? David Kelley has a short post about them on his blog. Isolated Storage Made Easy David Kelley also has a quick post up about Isolated Storage ... going to keep an eye out for more of these quick "Made Easy" posts from David. Prism 4.0 First Drop – MVVM Matias Bonaventura has a post up about the recent Prism 4.0 drop and highlights a bunch of the features/enhancements in this... some code snippets and a linnk out to the CodePlex drop. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • WordPress plugin for handling User Submitted Posts

    - by Ravish
    User Submitted Posts plugin is a highly useful form, which can be embedded on the desired areas of your WordPress site using a shortcode. User Submitted Posts plugin will allow you to customize the fields in the form like title, or tags. It provides you with useful tools to control uploads. Why you need this? [...] Related posts:Insights WordPress Plugin For Efficient Blogging WordPress User related Plug-ins AddInto Social Bookmarking plugin for WordPress & Blogger

    Read the article

  • 11 Ubuntu One Features You May Not Be Aware Of

    - by Chris Hoffman
    While Ubuntu One might seem like a Ubuntu-only file synchronization service, it’s more than that – you can use Ubuntu One on Windows, Android, iOS, and from the web. Ubuntu One offers 5GB of free storage space to everyone. Ubuntu One includes features for sharing files or folders online, streaming music to your smartphone, synchronizing installed applications across all your devices, and more. How to Use an Xbox 360 Controller On Your Windows PC Download the Official How-To Geek Trivia App for Windows 8 How to Banish Duplicate Photos with VisiPic

    Read the article

  • SOS, i erased a disk,1T.by mistake

    - by gabriel
    i tried to make bootable a flash drive from the startup disk creator, and i wanted to copy an iso of the 11.10 ubuntu, and when i tried to erase the flash drive i pressed erase on another removable drive 1T storage by mistake, VVVery very very quickly less than one second and with no warning everything was erased i suppose.Is that thing possible?When i tried before theis to erase the flash drive it took around a minute to erase the 8GB.But now less than a second for 1T? Please help, Gabriel

    Read the article

  • Working with Sub-Optimal Disk Configurations (Making the best of what you’ve got)

    - by Jonathan Kehayias
    This is the first post in a what will be a series of posts on working with a sub-optimal disk configuration to squeeze as much performance out of it as possible.  You might ask what a Sub-Optimal Disk Configuration?  In this case it is a Dell Powervault MD3000 with 15 Seagate Barracuda ES.2 SAS 1 TB 7.2K RPM disks (Model Number ST31000640SS).  This equates to just under 14TB of raw storage that can configured into a number of RAID configurations.  In this case, the disk array...(read more)

    Read the article

  • C#/.NET Little Wonders: The ConcurrentDictionary

    - by James Michael Hare
    Once again we consider some of the lesser known classes and keywords of C#.  In this series of posts, we will discuss how the concurrent collections have been developed to help alleviate these multi-threading concerns.  Last week’s post began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  Today's post discusses the ConcurrentDictionary<T> (originally I had intended to discuss ConcurrentBag this week as well, but ConcurrentDictionary had enough information to create a very full post on its own!).  Finally next week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. Recap As you'll recall from the previous post, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  While these were convenient because you didn't have to worry about writing your own synchronization logic, they were a bit too finely grained and if you needed to perform multiple operations under one lock, the automatic synchronization didn't buy much. With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  This cuts both ways in that you have a lot more control as a developer over when and how fine-grained you want to synchronize, but on the other hand if you just want simple synchronization it creates more work. With .NET 4.0, we get the best of both worlds in generic collections.  A new breed of collections was born called the concurrent collections in the System.Collections.Concurrent namespace.  These amazing collections are fine-tuned to have best overall performance for situations requiring concurrent access.  They are not meant to replace the generic collections, but to simply be an alternative to creating your own locking mechanisms. Among those concurrent collections were the ConcurrentStack<T> and ConcurrentQueue<T> which provide classic LIFO and FIFO collections with a concurrent twist.  As we saw, some of the traditional methods that required calls to be made in a certain order (like checking for not IsEmpty before calling Pop()) were replaced in favor of an umbrella operation that combined both under one lock (like TryPop()). Now, let's take a look at the next in our series of concurrent collections!For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentDictionary – the fully thread-safe dictionary The ConcurrentDictionary<TKey,TValue> is the thread-safe counterpart to the generic Dictionary<TKey, TValue> collection.  Obviously, both are designed for quick – O(1) – lookups of data based on a key.  If you think of algorithms where you need lightning fast lookups of data and don’t care whether the data is maintained in any particular ordering or not, the unsorted dictionaries are generally the best way to go. Note: as a side note, there are sorted implementations of IDictionary, namely SortedDictionary and SortedList which are stored as an ordered tree and a ordered list respectively.  While these are not as fast as the non-sorted dictionaries – they are O(log2 n) – they are a great combination of both speed and ordering -- and still greatly outperform a linear search. Now, once again keep in mind that if all you need to do is load a collection once and then allow multi-threaded reading you do not need any locking.  Examples of this tend to be situations where you load a lookup or translation table once at program start, then keep it in memory for read-only reference.  In such cases locking is completely non-productive. However, most of the time when we need a concurrent dictionary we are interleaving both reads and updates.  This is where the ConcurrentDictionary really shines!  It achieves its thread-safety with no common lock to improve efficiency.  It actually uses a series of locks to provide concurrent updates, and has lockless reads!  This means that the ConcurrentDictionary gets even more efficient the higher the ratio of reads-to-writes you have. ConcurrentDictionary and Dictionary differences For the most part, the ConcurrentDictionary<TKey,TValue> behaves like it’s Dictionary<TKey,TValue> counterpart with a few differences.  Some notable examples of which are: Add() does not exist in the concurrent dictionary. This means you must use TryAdd(), AddOrUpdate(), or GetOrAdd().  It also means that you can’t use a collection initializer with the concurrent dictionary. TryAdd() replaced Add() to attempt atomic, safe adds. Because Add() only succeeds if the item doesn’t already exist, we need an atomic operation to check if the item exists, and if not add it while still under an atomic lock. TryUpdate() was added to attempt atomic, safe updates. If we want to update an item, we must make sure it exists first and that the original value is what we expected it to be.  If all these are true, we can update the item under one atomic step. TryRemove() was added to attempt atomic, safe removes. To safely attempt to remove a value we need to see if the key exists first, this checks for existence and removes under an atomic lock. AddOrUpdate() was added to attempt an thread-safe “upsert”. There are many times where you want to insert into a dictionary if the key doesn’t exist, or update the value if it does.  This allows you to make a thread-safe add-or-update. GetOrAdd() was added to attempt an thread-safe query/insert. Sometimes, you want to query for whether an item exists in the cache, and if it doesn’t insert a starting value for it.  This allows you to get the value if it exists and insert if not. Count, Keys, Values properties take a snapshot of the dictionary. Accessing these properties may interfere with add and update performance and should be used with caution. ToArray() returns a static snapshot of the dictionary. That is, the dictionary is locked, and then copied to an array as a O(n) operation.  GetEnumerator() is thread-safe and efficient, but allows dirty reads. Because reads require no locking, you can safely iterate over the contents of the dictionary.  The only downside is that, depending on timing, you may get dirty reads. Dirty reads during iteration The last point on GetEnumerator() bears some explanation.  Picture a scenario in which you call GetEnumerator() (or iterate using a foreach, etc.) and then, during that iteration the dictionary gets updated.  This may not sound like a big deal, but it can lead to inconsistent results if used incorrectly.  The problem is that items you already iterated over that are updated a split second after don’t show the update, but items that you iterate over that were updated a split second before do show the update.  Thus you may get a combination of items that are “stale” because you iterated before the update, and “fresh” because they were updated after GetEnumerator() but before the iteration reached them. Let’s illustrate with an example, let’s say you load up a concurrent dictionary like this: 1: // load up a dictionary. 2: var dictionary = new ConcurrentDictionary<string, int>(); 3:  4: dictionary["A"] = 1; 5: dictionary["B"] = 2; 6: dictionary["C"] = 3; 7: dictionary["D"] = 4; 8: dictionary["E"] = 5; 9: dictionary["F"] = 6; Then you have one task (using the wonderful TPL!) to iterate using dirty reads: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); And one task to attempt updates in a separate thread (probably): 1: // attempt updates in a separate thread 2: var updateTask = new Task(() => 3: { 4: // iterates, and updates the value by one 5: foreach (var pair in dictionary) 6: { 7: dictionary[pair.Key] = pair.Value + 1; 8: } 9: }); Now that we’ve done this, we can fire up both tasks and wait for them to complete: 1: // start both tasks 2: updateTask.Start(); 3: iterationTask.Start(); 4:  5: // wait for both to complete. 6: Task.WaitAll(updateTask, iterationTask); Now, if I you didn’t know about the dirty reads, you may have expected to see the iteration before the updates (such as A:1, B:2, C:3, D:4, E:5, F:6).  However, because the reads are dirty, we will quite possibly get a combination of some updated, some original.  My own run netted this result: 1: F:6 2: E:6 3: D:5 4: C:4 5: B:3 6: A:2 Note that, of course, iteration is not in order because ConcurrentDictionary, like Dictionary, is unordered.  Also note that both E and F show the value 6.  This is because the output task reached F before the update, but the updates for the rest of the items occurred before their output (probably because console output is very slow, comparatively). If we want to always guarantee that we will get a consistent snapshot to iterate over (that is, at the point we ask for it we see precisely what is in the dictionary and no subsequent updates during iteration), we should iterate over a call to ToArray() instead: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary.ToArray()) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); The atomic Try…() methods As you can imagine TryAdd() and TryRemove() have few surprises.  Both first check the existence of the item to determine if it can be added or removed based on whether or not the key currently exists in the dictionary: 1: // try add attempts an add and returns false if it already exists 2: if (dictionary.TryAdd("G", 7)) 3: Console.WriteLine("G did not exist, now inserted with 7"); 4: else 5: Console.WriteLine("G already existed, insert failed."); TryRemove() also has the virtue of returning the value portion of the removed entry matching the given key: 1: // attempt to remove the value, if it exists it is removed and the original is returned 2: int removedValue; 3: if (dictionary.TryRemove("C", out removedValue)) 4: Console.WriteLine("Removed C and its value was " + removedValue); 5: else 6: Console.WriteLine("C did not exist, remove failed."); Now TryUpdate() is an interesting creature.  You might think from it’s name that TryUpdate() first checks for an item’s existence, and then updates if the item exists, otherwise it returns false.  Well, note quite... It turns out when you call TryUpdate() on a concurrent dictionary, you pass it not only the new value you want it to have, but also the value you expected it to have before the update.  If the item exists in the dictionary, and it has the value you expected, it will update it to the new value atomically and return true.  If the item is not in the dictionary or does not have the value you expected, it is not modified and false is returned. 1: // attempt to update the value, if it exists and if it has the expected original value 2: if (dictionary.TryUpdate("G", 42, 7)) 3: Console.WriteLine("G existed and was 7, now it's 42."); 4: else 5: Console.WriteLine("G either didn't exist, or wasn't 7."); The composite Add methods The ConcurrentDictionary also has composite add methods that can be used to perform updates and gets, with an add if the item is not existing at the time of the update or get. The first of these, AddOrUpdate(), allows you to add a new item to the dictionary if it doesn’t exist, or update the existing item if it does.  For example, let’s say you are creating a dictionary of counts of stock ticker symbols you’ve subscribed to from a market data feed: 1: public sealed class SubscriptionManager 2: { 3: private readonly ConcurrentDictionary<string, int> _subscriptions = new ConcurrentDictionary<string, int>(); 4:  5: // adds a new subscription, or increments the count of the existing one. 6: public void AddSubscription(string tickerKey) 7: { 8: // add a new subscription with count of 1, or update existing count by 1 if exists 9: var resultCount = _subscriptions.AddOrUpdate(tickerKey, 1, (symbol, count) => count + 1); 10:  11: // now check the result to see if we just incremented the count, or inserted first count 12: if (resultCount == 1) 13: { 14: // subscribe to symbol... 15: } 16: } 17: } Notice the update value factory Func delegate.  If the key does not exist in the dictionary, the add value is used (in this case 1 representing the first subscription for this symbol), but if the key already exists, it passes the key and current value to the update delegate which computes the new value to be stored in the dictionary.  The return result of this operation is the value used (in our case: 1 if added, existing value + 1 if updated). Likewise, the GetOrAdd() allows you to attempt to retrieve a value from the dictionary, and if the value does not currently exist in the dictionary it will insert a value.  This can be handy in cases where perhaps you wish to cache data, and thus you would query the cache to see if the item exists, and if it doesn’t you would put the item into the cache for the first time: 1: public sealed class PriceCache 2: { 3: private readonly ConcurrentDictionary<string, double> _cache = new ConcurrentDictionary<string, double>(); 4:  5: // adds a new subscription, or increments the count of the existing one. 6: public double QueryPrice(string tickerKey) 7: { 8: // check for the price in the cache, if it doesn't exist it will call the delegate to create value. 9: return _cache.GetOrAdd(tickerKey, symbol => GetCurrentPrice(symbol)); 10: } 11:  12: private double GetCurrentPrice(string tickerKey) 13: { 14: // do code to calculate actual true price. 15: } 16: } There are other variations of these two methods which vary whether a value is provided or a factory delegate, but otherwise they work much the same. Oddities with the composite Add methods The AddOrUpdate() and GetOrAdd() methods are totally thread-safe, on this you may rely, but they are not atomic.  It is important to note that the methods that use delegates execute those delegates outside of the lock.  This was done intentionally so that a user delegate (of which the ConcurrentDictionary has no control of course) does not take too long and lock out other threads. This is not necessarily an issue, per se, but it is something you must consider in your design.  The main thing to consider is that your delegate may get called to generate an item, but that item may not be the one returned!  Consider this scenario: A calls GetOrAdd and sees that the key does not currently exist, so it calls the delegate.  Now thread B also calls GetOrAdd and also sees that the key does not currently exist, and for whatever reason in this race condition it’s delegate completes first and it adds its new value to the dictionary.  Now A is done and goes to get the lock, and now sees that the item now exists.  In this case even though it called the delegate to create the item, it will pitch it because an item arrived between the time it attempted to create one and it attempted to add it. Let’s illustrate, assume this totally contrived example program which has a dictionary of char to int.  And in this dictionary we want to store a char and it’s ordinal (that is, A = 1, B = 2, etc).  So for our value generator, we will simply increment the previous value in a thread-safe way (perhaps using Interlocked): 1: public static class Program 2: { 3: private static int _nextNumber = 0; 4:  5: // the holder of the char to ordinal 6: private static ConcurrentDictionary<char, int> _dictionary 7: = new ConcurrentDictionary<char, int>(); 8:  9: // get the next id value 10: public static int NextId 11: { 12: get { return Interlocked.Increment(ref _nextNumber); } 13: } Then, we add a method that will perform our insert: 1: public static void Inserter() 2: { 3: for (int i = 0; i < 26; i++) 4: { 5: _dictionary.GetOrAdd((char)('A' + i), key => NextId); 6: } 7: } Finally, we run our test by starting two tasks to do this work and get the results… 1: public static void Main() 2: { 3: // 3 tasks attempting to get/insert 4: var tasks = new List<Task> 5: { 6: new Task(Inserter), 7: new Task(Inserter) 8: }; 9:  10: tasks.ForEach(t => t.Start()); 11: Task.WaitAll(tasks.ToArray()); 12:  13: foreach (var pair in _dictionary.OrderBy(p => p.Key)) 14: { 15: Console.WriteLine(pair.Key + ":" + pair.Value); 16: } 17: } If you run this with only one task, you get the expected A:1, B:2, ..., Z:26.  But running this in parallel you will get something a bit more complex.  My run netted these results: 1: A:1 2: B:3 3: C:4 4: D:5 5: E:6 6: F:7 7: G:8 8: H:9 9: I:10 10: J:11 11: K:12 12: L:13 13: M:14 14: N:15 15: O:16 16: P:17 17: Q:18 18: R:19 19: S:20 20: T:21 21: U:22 22: V:23 23: W:24 24: X:25 25: Y:26 26: Z:27 Notice that B is 3?  This is most likely because both threads attempted to call GetOrAdd() at roughly the same time and both saw that B did not exist, thus they both called the generator and one thread got back 2 and the other got back 3.  However, only one of those threads can get the lock at a time for the actual insert, and thus the one that generated the 3 won and the 3 was inserted and the 2 got discarded.  This is why on these methods your factory delegates should be careful not to have any logic that would be unsafe if the value they generate will be pitched in favor of another item generated at roughly the same time.  As such, it is probably a good idea to keep those generators as stateless as possible. Summary The ConcurrentDictionary is a very efficient and thread-safe version of the Dictionary generic collection.  It has all the benefits of type-safety that it’s generic collection counterpart does, and in addition is extremely efficient especially when there are more reads than writes concurrently. Tweet Technorati Tags: C#, .NET, Concurrent Collections, Collections, Little Wonders, Black Rabbit Coder,James Michael Hare

    Read the article

  • Apple met à jour son Mac Mini : un nouveau design, et un démontage plus aisé, mais un prix salé

    Apple vient de dévoilé son nouveau MacMini : Citation: Apple Unveils All New Mac mini CUPERTINO, California?June 15, 2010?Apple® today unveiled a completely redesigned Mac® mini, featuring up to twice the graphics performance, a new HDMI port and a new SD card slot, all in an amazingly compact aluminum enclosure. Mac mini is the world's most energy efficient desktop and starting at $699, is the most affordable way to enjoy Mac OS® X, iLife® or Mac OS X Snow Leopard® Server. ?The sleek, aluminum Mac mini packs gre...

    Read the article

  • Silverlight for Everyone!!

    - by subodhnpushpak
    Someone asked me to compare Silverlight / HTML development. I realized that the question can be answered in many ways: Below is the high level comparison between a HTML /JavaScript client and Silverlight client and why silverlight was chosen over HTML / JavaScript client (based on type of users and major functionalities provided): 1. For end users Browser compatibility Silverlight is a plug-in and requires installation first. However, it does provides consistent look and feel across all browsers. For HTML / DHTML, there is a need to tweak JavaScript for each of the browser supported. In fact, tags like <span> and <div> works differently on different browser / version. So, HTML works on most of the systems but also requires lot of efforts coding-wise to adhere to all standards/ browsers / versions. Out of browser support No support in HTML. Third party tools like  Google gears offers some functionalities but there are lots of issues around platform and accessibility. Out of box support for out-of-browser support. provides features like drag and drop onto application surface. Cut and copy paste in HTML HTML is displayed in browser; which, in turn provides facilities for cut copy and paste. Silverlight (specially 4) provides rich features for cut-copy-paste along with full control over what can be cut copy pasted by end users and .advanced features like visual tree printing. Rich user experience HTML can provide some rich experience by use of some JavaScript libraries like JQuery. However, extensive use of JavaScript combined with various versions of browsers and the supported JavaScript makes the solution cumbersome. Silverlight is meant for RIA experience. User data storage on client end In HTML only small amount of data can be stored that too in cookies. In Silverlight large data may be stored, that too in secure way. This increases the response time. Post back In HTML / JavaScript the post back can be stopped by use of AJAX. Extensive use of AJAX can be a bottleneck as browser stack is used for the calls. Both look and feel and data travel over network.                           In Silverlight everything run the client side. Calls are made to server ONLY for data; which also reduces network traffic in long run. 2. For Developers Coding effort HTML / JavaScript can take considerable amount to code if features (requirements) are rich. For AJAX like interfaces; knowledge of third party kits like DOJO / Yahoo UI / JQuery is required which has steep learning curve. ASP .Net coding world revolves mostly along <table> tags for alignments whereas most popular tools provide <div> tags; which requires lots of tweaking. AJAX calls can be a bottlenecks for performance, if the calls are many. In Silverlight; coding is in C#, which is managed code. XAML is also very intuitive and Blend can be used to provide look and feel. Event handling is much clean than in JavaScript. Provides for many clean patterns like MVVM and composable application. Each call to server is asynchronous in silverlight. AJAX is in built into silverlight. Threading can be done at the client side itself to provide for better responsiveness; etc. Debugging Debugging in HTML / JavaScript is difficult. As JavaScript is interpreted; there is NO compile time error handling. Debugging in Silverlight is very helpful. As it is compiled; it provides rich features for both compile time and run time error handling. Multi -targeting browsers HTML / JavaScript have different rendering behaviours in different browsers / and their versions. JavaScript have to be written to sublime the differences in browser behaviours. Silverlight works exactly the same in all browsers and works on almost all popular browser. Multi-targeting desktop No support in HTML / JavaScript Silverlight is very close to WPF. Bot the platform may be easily targeted while maintaining the same source code. Rich toolkit HTML /JavaScript have limited toolkit as controls Silverlight provides a rich set of controls including graphs, audio, video, layout, etc. 3. For Architects Design Patterns Silverlight provides for patterns like MVVM (MVC) and rich (fat)  client architecture. This segregates the "separation of concern" very clearly. Client (silverlight) does what it is expected to do and server does what it is expected of. In HTML / JavaScript world most of the processing is done on the server side. Extensibility Silverlight provides great deal of extensibility as custom controls may be made. Extensibility is NOT restricted by browser but by the plug-in silverlight runs in. HTML / JavaScript works in a certain way and extensibility is generally done on the server side rather than client end. Client side is restricted by the limitations of the browser. Performance Silverlight provides localized storage which may be used for cached data storage. this reduces the response time. As processing can be done on client side itself; there is no need for server round trips. this decreases the round about time. Look and feel of the application is downloaded ONLY initially, afterwards ONLY data is fetched form the server. Security Silverlight is compiled code downloaded as .XAP; As compared to HTML / JavaScript, it provides more secure sandboxed approach. Cross - scripting is inherently prohibited in silverlight by default. If proper guidelines are followed silverlight provides much robust security mechanism as against HTML / JavaScript world. For example; knowing server Address in obfuscated JavaScript is easier than a compressed compiled obfuscated silverlight .XAP file. Some of these like (offline and Canvas support) will be available in HTML5. However, the timelines are not encouraging at all. According to Ian Hickson, editor of the HTML5 specification, the specification to reach the W3C Candidate Recommendation stage during 2012, and W3C Recommendation in the year 2022 or later. see http://en.wikipedia.org/wiki/HTML5 for details. The above is MY opinion. I will love to hear yours; do let me know via comments. Technorati Tags: Silverlight

    Read the article

  • Ha a hutés nem elég a gépteremben: Sun Cooling Door a Database Machine-hoz

    - by Fekete Zoltán
    A Database Machine hatalmas teljesítménye miatt általában jóval kevesebb hutésre van szükség, mintha egy külön high-end servert és külön high-end storage-ot hutenénk! Ha viszont a géptermünk maradék hutési kapacitása nem elegendo, és nem elégszünk meg a "hagyományos mosóporral", akkor újabb hutési trükkre van szükség. Erre kínálnak megoldást a Sun Cooling Door modellek, például az 5200-as és az 5600-as modellek.

    Read the article

  • Uploading to my local server is slower than downloading from the Internet

    - by Olivier Lalonde
    I have a home Ubuntu server that I use for storage. I have mounted a sftp share on my laptop to access my server but the upload speed I get is very slow (~400kb/s) compared to speeds I usually get when downloading through Bittorrent (~800kb/s). It's kind of weird... I should get higher speeds on a LAN than on the Internet... How can I speed up uploads to my server and how can I troubleshoot where the bottleneck is?

    Read the article

  • Oracle Expands Sun Blade Portfolio for Cloud and Highly Virtualized Environments

    - by Ferhat Hatay
    Oracle announced the expansion of Sun Blade Portfolio for cloud and highly virtualized environments that deliver powerful performance and simplified management as tightly integrated systems.  Along with the SPARC T3-1B blade server, Oracle VM blade cluster reference configuration and Oracle's optimized solution for Oracle WebLogic Suite, Oracle introduced the dual-node Sun Blade X6275 M2 server module with some impressive benchmark results.   Benchmarks on the Sun Blade X6275 M2 server module demonstrate the outstanding performance characteristics critical for running varied commercial applications used in cloud and highly virtualized environments.  These include best-in-class SPEC CPU2006 results with the Intel Xeon processor 5600 series, six Fluent world records and 1.8 times the price-performance of the IBM Power 755 running NAMD, a prominent bio-informatics workload.   Benchmarks for Sun Blade X6275 M2 server module  SPEC CPU2006  The Sun Blade X6275 M2 server module demonstrated best in class SPECint_rate2006 results for all published results using the Intel Xeon processor 5600 series, with a result of 679.  This result is 97% better than the HP BL460c G7 blade, 80% better than the IBM HS22V blade, and 79% better than the Dell M710 blade.  This result demonstrates the density advantage of the new Oracle's server module for space-constrained data centers.     Sun Blade X6275M2 (2 Nodes, Intel Xeon X5670 2.93GHz) - 679 SPECint_rate2006; HP ProLiant BL460c G7 (2.93 GHz, Intel Xeon X5670) - 347 SPECint_rate2006; IBM BladeCenter HS22V (Intel Xeon X5680)  - 377 SPECint_rate2006; Dell PowerEdge M710 (Intel Xeon X5680, 3.33 GHz) - 380 SPECint_rate2006.  SPEC, SPECint, SPECfp reg tm of Standard Performance Evaluation Corporation. Results from www.spec.org as of 11/24/2010 and this report.    For more specifics about these results, please go to see http://blogs.sun.com/BestPerf   Fluent The Sun Fire X6275 M2 server module produced world-record results on each of the six standard cases in the current "FLUENT 12" benchmark test suite at 8-, 12-, 24-, 32-, 64- and 96-core configurations. These results beat the most recent QLogic score with IBM DX 360 M series platforms and QLogic "Truescale" interconnects.  Results on sedan_4m test case on the Sun Blade X6275 M2 server module are 23% better than the HP C7000 system, and 20% better than the IBM DX 360 M2; Dell has not posted a result for this test case.  Results can be found at the FLUENT website.   ANSYS's FLUENT software solves fluid flow problems, and is based on a numerical technique called computational fluid dynamics (CFD), which is used in the automotive, aerospace, and consumer products industries. The FLUENT 12 benchmark test suite consists of seven models that are well suited for multi-node clustered environments and representative of modern engineering CFD clusters. Vendors benchmark their systems with the principal objective of providing comparative performance information for FLUENT software that, among other things, depends on compilers, optimization, interconnect, and the performance characteristics of the hardware.   FLUENT application performance is representative of other commercial applications that require memory and CPU resources to be available in a scalable cluster-ready format.  FLUENT benchmark has six conventional test cases (eddy_417k, turbo_500k, aircraft_2m, sedan_4m, truck_14m, truck_poly_14m) at various core counts.   All information on the FLUENT website (http://www.fluent.com) is Copyrighted1995-2010 by ANSYS Inc. Results as of November 24, 2010. For more specifics about these results, please go to see http://blogs.sun.com/BestPerf   NAMD Results on the Sun Blade X6275 M2 server module running NAMD (a parallel molecular dynamics code designed for high-performance simulation of large biomolecular systems) show up to a 1.8X better price/performance than IBM's Power 7-based system.  For space-constrained environments, the ultra-dense Sun Blade X6275 M2 server module provides a 1.7X better price/performance per rack unit than IBM's system.     IBM Power 755 4-way Cluster (16U). Total price for cluster: $324,212. See IBM United States Hardware Announcement 110-008, dated February 9, 2010, pp. 4, 21 and 39-46.  Sun Blade X6275 M2 8-Blade Cluster (10U). Total price for cluster:  $193,939. Price/performance and performance/RU comparisons based on f1ATPase molecule test results. Sun Blade X6275 M2 cluster: $3,568/step/sec, 5.435 step/sec/RU. IBM Power 755 cluster: $6,355/step/sec, 3.189 step/sec/U. See http://www-03.ibm.com/systems/power/hardware/reports/system_perf.html. See http://www.ks.uiuc.edu/Research/namd/performance.html for more information, results as of 11/24/10.   For more specifics about these results, please go to see http://blogs.sun.com/BestPerf   Reverse Time Migration The Reverse Time Migration is heavily used in geophysical imaging and modeling for Oil & Gas Exploration.  The Sun Blade X6275 M2 server module showed up to a 40% performance improvement over the previous generation server module with super-linear scalability to 16 nodes for the 9-Point Stencil used in this Reverse Time Migration computational kernel.  The balanced combination of Oracle's Sun Storage 7410 system with the Sun Blade X6275 M2 server module cluster showed linear scalability for the total application throughput, including the I/O and MPI communication, to produce a final 3-D seismic depth imaged cube for interpretation. The final image write time from the Sun Blade X6275 M2 server module nodes to Oracle's Sun Storage 7410 system achieved 10GbE line speed of 1.25 GBytes/second or better performance. Between subsequent runs, the effects of I/O buffer caching on the Sun Blade X6275 M2 server module nodes and write optimized caching on the Sun Storage 7410 system gave up to 1.8 GBytes/second effective write performance. The performance results and characterization of this Reverse Time Migration benchmark could serve as a useful measure for many other I/O intensive commercial applications. 3D VTI Reverse Time Migration Seismic Depth Imaging, see http://blogs.sun.com/BestPerf/entry/3d_vti_reverse_time_migration for more information, results as of 11/14/2010.                            

    Read the article

  • Clustering for Mere Mortals (Pt 3)

    - by Geoff N. Hiten
    The Controller Now we get to the meat of the matter.  You want a virtual cluster, the first thing you have to do is create your own portable domain.  Start with a plain vanilla install of Windows 2003 R2 Standard on a semi-default VM. (1 GB RAM, 2 cores, 2 NICs, 128GB dynamically expanding VHD file).  I chose this because it had the smallest disk and memory footprint of any current supported Microsoft Server product.  I created the VM with a single dynamically expanding VHD, one fixed 16 GB VHD, and two NICs.  One NIC is connected to the outside world and the other one is part of an internal-only network.  The first NIC is set up as a DHCP client.  We will get to the other one later. I actually tried this with Windows 2008 R2, but it failed miserably.  Not sure whether it was 2008 R2 or the fact I tried to use cloned VMs in the cluster.  Clustering is one place where NewSID would really come in handy.  Too bad Microsoft bought and buried it. Load and Patch the OS (hence the need for the outside connection).This is a good time to go get dinner.  Maybe a movie too.  There are close to a hundred patches that need to be downloaded and applied.  Avoiding that mess was why I put so much time into trying to get the 2008 R2 version working.  Maybe next time.  Don’t forget to add the extensions for VMLite (or whatever virtualization product you prefer). Set a fixed IP address on the internal-only NIC.  Do not give it a gateway.  Put the same IP address for the NIC and for the DNS Server.  This IP should be in a range that is never available on your public network.  You will need all the addresses in the range available.  See the previous post for the exact settings I used. I chose 10.97.230.1 as the server.  The rest of the 10.97.230 range is what I will use later.  For the curious, those numbers are based on elements of my home address.  Not truly random, but good enough for this project. Do not bridge the network connections.  I never allowed the cluster nodes direct access to any public network. Format the fixed VHD and leave it alone for now. Promote the VM to a Domain Controller.  If you have never done this, don’t worry.  The only meaningful decision is what to call the new domain.  I prefer a bogus name that does not correspond to a real Top-Level Domain (TLD).  .com, .biz., .net, .org  are all TLDs that we know and love.  I chose .test as the TLD since it is descriptive AND it does not exist in the real world.  The domain is called MicroAD.  This gives me MicroAD.Test as my domain. During the promotion process, you will be prompted to install DNS as part of the Domain creation process.  You want to accept this option.  The installer will automatically assign this DNS server as the authoritative owner of the MicroAD.test DNS domain (not to be confused with the MicroAD.test Active Directory domain.) For the rest of the DCPROMO process, just accept the defaults. Now let’s make our IP address management easy.  Add the DHCP Role to the server.  Add the server (10.97.230.1 in this case) as the default gateway to assign to DHCP clients.  Here is where you have to be VERY careful and bind it ONLY to the Internal NIC.  Trust me, your network admin will NOT like an extra DHCP server “helping” out on her network.  Go ahead and create a range of 10-20 IP Addresses in your scope.  You might find other uses for a pocket domain controller <cough> Mirroring </cough> than just for building a cluster.  And Clustering in SQL 2008 and Windows 2008 R2 fully supports DHCP addresses. Now we have three of the five key roles ready.  Two more to go. Next comes file sharing.  Since your cluster node VMs will not have access to any outside, you have to have some way to get files into these VMs.  I simply go to the root of C: and create a “Shared” folder.  I then share it out and grant full control to “Everyone” to both the share and to the underlying NTFS folder.   This will be immensely useful for Service Packs, demo databases, and any other software that isn’t packaged as an ISO that we can mount to the VM. Finally we need to create a block-level multi-connect storage device.  The kind folks at Starwinds Software (http://www.starwindsoftware.com/) graciously gave me a non-expiring demo license for expressly this purpose.  Their iSCSI SAN software lets you create an iSCSI target from nearly any storage medium.  Refreshingly, their product does exactly what they say it does.  Thanks. Remember that 16 GB VHD file?  That is where we are going to carve into our LUNs.  I created an iSCSI folder off the root, just so I can keep everything organized.  I then carved 5 ea. 2 GB iSCSI targets from that folder.  I chose a fixed VHD for performance.  I tried this earlier with a dynamically expanding VHD, but too many layers of abstraction and sparseness combined to make it unusable even for a demo.  Stick with a fixed VHD so there is a one-to-one mapping between abstract and physical storage.  If you read the previous post, you know what I named these iSCSI LUNs and why.  Yes, I do have some left over space.  Always leave yourself room for future growth or options. This gets us up to where we can actually build the nodes and install SQL.  As with most clusters, the real work happens long before the individual nodes get installed and configured.  At least it does if you want the cluster to be a true high-availability platform.

    Read the article

  • SQL Server SELECT INTO

    - by Derek Dieter
    The most efficient method of copying a result set into a new table is to use the SELECT INTO method. This method also follows a very simple syntax. [/sql] SELECT * INTO dbo.NewTableName FROM dbo.ExistingTable [sql] Once the query above is executed, all the columns and data in the table ExistingTable (along with their datatypes) will be copied into a [...]

    Read the article

  • The Data Scientist

    - by BuckWoody
    A new term - well, perhaps not that new - has come up and I’m actually very excited about it. The term is Data Scientist, and since it’s new, it’s fairly undefined. I’ll explain what I think it means, and why I’m excited about it. In general, I’ve found the term deals at its most basic with analyzing data. Of course, we all do that, and the term itself in that definition is redundant. There is no science that I know of that does not work with analyzing lots of data. But the term seems to refer to more than the common practices of looking at data visually, putting it in a spreadsheet or report, or even using simple coding to examine data sets. The term Data Scientist (as far as I can make out this early in it’s use) is someone who has a strong understanding of data sources, relevance (statistical and otherwise) and processing methods as well as front-end displays of large sets of complicated data. Some - but not all - Business Intelligence professionals have these skills. In other cases, senior developers, database architects or others fill these needs, but in my experience, many lack the strong mathematical skills needed to make these choices properly. I’ve divided the knowledge base for someone that would wear this title into three large segments. It remains to be seen if a given Data Scientist would be responsible for knowing all these areas or would specialize. There are pretty high requirements on the math side, specifically in graduate-degree level statistics, but in my experience a company will only have a few of these folks, so they are expected to know quite a bit in each of these areas. Persistence The first area is finding, cleaning and storing the data. In some cases, no cleaning is done prior to storage - it’s just identified and the cleansing is done in a later step. This area is where the professional would be able to tell if a particular data set should be stored in a Relational Database Management System (RDBMS), across a set of key/value pair storage (NoSQL) or in a file system like HDFS (part of the Hadoop landscape) or other methods. Or do you examine the stream of data without storing it in another system at all? This is an important decision - it’s a foundation choice that deals not only with a lot of expense of purchasing systems or even using Cloud Computing (PaaS, SaaS or IaaS) to source it, but also the skillsets and other resources needed to care and feed the system for a long time. The Data Scientist sets something into motion that will probably outlast his or her career at a company or organization. Often these choices are made by senior developers, database administrators or architects in a company. But sometimes each of these has a certain bias towards making a decision one way or another. The Data Scientist would examine these choices in light of the data itself, starting perhaps even before the business requirements are created. The business may not even be aware of all the strategic and tactical data sources that they have access to. Processing Once the decision is made to store the data, the next set of decisions are based around how to process the data. An RDBMS scales well to a certain level, and provides a high degree of ACID compliance as well as offering a well-known set-based language to work with this data. In other cases, scale should be spread among multiple nodes (as in the case of Hadoop landscapes or NoSQL offerings) or even across a Cloud provider like Windows Azure Table Storage. In fact, in many cases - most of the ones I’m dealing with lately - the data should be split among multiple types of processing environments. This is a newer idea. Many data professionals simply pick a methodology (RDBMS with Star Schemas, NoSQL, etc.) and put all data there, regardless of its shape, processing needs and so on. A Data Scientist is familiar not only with the various processing methods, but how they work, so that they can choose the right one for a given need. This is a huge time commitment, hence the need for a dedicated title like this one. Presentation This is where the need for a Data Scientist is most often already being filled, sometimes with more or less success. The latest Business Intelligence systems are quite good at allowing you to create amazing graphics - but it’s the data behind the graphics that are the most important component of truly effective displays. This is where the mathematics requirement of the Data Scientist title is the most unforgiving. In fact, someone without a good foundation in statistics is not a good candidate for creating reports. Even a basic level of statistics can be dangerous. Anyone who works in analyzing data will tell you that there are multiple errors possible when data just seems right - and basic statistics bears out that you’re on the right track - that are only solvable when you understanding why the statistical formula works the way it does. And there are lots of ways of presenting data. Sometimes all you need is a “yes” or “no” answer that can only come after heavy analysis work. In that case, a simple e-mail might be all the reporting you need. In others, complex relationships and multiple components require a deep understanding of the various graphical methods of presenting data. Knowing which kind of chart, color, graphic or shape conveys a particular datum best is essential knowledge for the Data Scientist. Why I’m excited I love this area of study. I like math, stats, and computing technologies, but it goes beyond that. I love what data can do - how it can help an organization. I’ve been fortunate enough in my professional career these past two decades to work with lots of folks who perform this role at companies from aerospace to medical firms, from manufacturing to retail. Interestingly, the size of the company really isn’t germane here. I worked with one very small bio-tech (cryogenics) company that worked deeply with analysis of complex interrelated data. So  watch this space. No, I’m not leaving Azure or distributed computing or Microsoft. In fact, I think I’m perfectly situated to investigate this role further. We have a huge set of tools, from RDBMS to Hadoop to allow me to explore. And I’m happy to share what I learn along the way.

    Read the article

  • Tutorial: Controlling Your Linux System With fstab

    The /etc/fstab file gives you control over what filesystems are mounted at startup on your Linux system, including Windows partitions and network shares. You can also use it to control the mount points of removable storage devices like USB sticks and external hard disks. Akkana Peck shows us how.

    Read the article

  • Recommended workflows for Apache virtual hosts?

    - by craig zheng
    I do a lot of local web development work on my Ubuntu machine, and I'm constantly setting up virtual hosts in Apache. I don't need to do hard core server management, but I am getting tired of the repetitive process of manually adding config directives to files in /etc/apache2/sites-available/ and then updating the /etc/hosts file. Is there a more efficient or more automated way to do all this that I'm missing? Maybe something like rapache but that's actually working?

    Read the article

  • Oracle Optimized Solutions at Oracle OpenWorld 2012

    - by ferhatSF
    Have you registered for Oracle OpenWorld 2012 in San Francisco from September 30 to October 4? Visit the Oracle OpenWorld 2012 site today for registration and more information. Come join us to hear how Oracle Optimized Solutions can help you save money, reduce integration risks, and improve user productivity. Oracle Optimized Solutions are designed, pre-tested, tuned and fully documented architectures for optimal performance and availability. They provide written guidelines to help size, configure, purchase and deploy enterprise solutions that address common IT problems. Built with flexibility in mind, Oracle Optimized Solutions can be deployed as complete solutions or easily tailored to meet your specific needs - they are proven to save money, reduce integration risks and improve user productivity. Here is a preview of the planned Oracle OpenWorld sessions(*) on Oracle Optimized Solutions. October 1, 2012 Monday Time Session ID Title Location 12:15 PM CON7916 Accelerate Oracle E-Business Suite Deployment with SPARC SuperCluster Moscone West - 2001 03:15 PM GEN9691 General Session: Accelerate Your Business with the Oracle Hardware Advantage Moscone North - Hall D 04:45 PM CON4821 Building a Flexible Enterprise Cloud Infrastructure on Oracle SPARC Systems Moscone West - 2001 October 2, 2012 Tuesday Time Session ID Title Location 10:15 AM CON4561 Backup-and-Recovery Best Practices with Oracle Engineered Systems Products Moscone South - 252 11:45 AM CON3851 Optimizing JD Edwards EnterpriseOne on SPARC T4 Servers for Best Performance Moscone West - 2000 01:15 PM GEN11472 General Session: Breakthrough Efficiency in Private Cloud Infrastructure Moscone West - 3014 01:15 PM CON4600 Extreme Storage Scale and Efficiency: Lessons from a 100,000-Person Organization Moscone South - 252 05:00 PM CON9465 Next-Generation Directory: Oracle Unified Directory Moscone West - 3008 05:00 PM CON4088 Accelerate Your SAP Landscape with the Oracle SPARC SuperCluster Moscone West - 2001 05:00 PM CON7743 High-Performance Security for Oracle Applications Using SPARC T4 Systems Moscone West - 2000 05:00 PM CON3857 Archive Strategies for 100 Percent Data Availability Moscone South - 270 October 3, 2012 Wednesday Time Session ID Title Location 10:15 AM CON6528 Configure Oracle Hybrid Columnar Compression to Optimize Query Database Performance up to 10x Moscone South - 252 11:45 AM CON2590 Breakthrough in Private Cloud Management on SPARC T-Series Servers Moscone South - 270 01:15 PM CON4289 Oracle Optimized Solution for Siebel CRM at ACCOR Moscone West - 2000 05:00 PM CON7570 Improve PeopleSoft HCM Performance and Reliability with SPARC SuperCluster Moscone South - 252 * Schedule subject to change In addition, there will be Oracle Optimized Solutions Hands-On-Labs sessions planned. Please enroll ahead of time as space is limited: Oracle Optimized Solutions: Hands on Labs in Oracle OpenWorld Place: Marriott Marquis - Salon 14/15 Date and Time Session ID Title Monday October 1, 2012 01:45 PM HOL9868 Enterprise Cloud Infrastructure for SPARC with Oracle Enterprise Manager Ops Center 12c Monday October 1, 2012 03:15 PM HOL9907 Oracle Virtual Desktop Infrastructure Performance and Tablet Mobility Wednesday October 3, 2012 05:00 PM HOL9870 x86 Enterprise Cloud Infrastructure with Oracle VM 3.x and Sun ZFS Storage Appliance Thursday October 4, 2012 11:15 AM HOL9869 0 to Database Backup and Recovery in 60 Minutes Oracle Optimized Solutions executives and experts will also be at hand for discussions and follow ups. And don’t forget to catch live demonstrations of our complete Oracle Optimized Solutions while at Oracle OpenWorld 2012 in San Francisco. We recommend the use of the Schedule Builder tool to plan your visit to the conference and for pre-enrollment in sessions of your interest. We hope to see you there!

    Read the article

< Previous Page | 116 117 118 119 120 121 122 123 124 125 126 127  | Next Page >