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• What kind of proxy acl rules should be applied?

  - by user42891

  I try to block sites in squid based on this article. Assuming you would want to block access to Yahoo (e.g http://www.yahoo.co.jp, http://www.yahoo.com, http://www.yahoo.co.in), you would ideally want to block all of the above URLs, if I use a regular expression and try to search something called yahoo it seems to get blocked. We are just interested in applying rules which would be most commonly used across all companies (e.g. social networking sites like facebook, orkut), porn sites (e.g. sex), gaming sites (games), movie & song download sites, and sites where they can upload data (e.g. rapidshare) What would be the common set of effective rules in achieving the above?

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• ESX Firewall Command Troubles

  - by John

  Hi, I am working on creating some firewall rules to stop some of the SSH brute-force attacks that we have seen recently on our ESX server hosts. I have tried the following rules from the CLI to first block all SSH traffic and then allow the two ranges that I am interested in: esxcfg-firewall --ipruleAdd 0.0.0.0/0,22,tcp,REJECT,"Block_SSH" esxcfg-firewall --ipruleAdd 11.130.0.0/16,22,tcp,ACCEPT,"Allow_PUBLIC_SSH" esxcfg-firewall --ipruleAdd 10.130.0.0/16,22,tcp,ACCEPT,"Allow_PRIVATE_SSH" However, these rules are not working as intended. I know that if you do not enter the block rule first, then the allow rule will not be processed. We are now having the issue where the first entered allow rule is being ignored such that the block rule works and the last entered allow rule works. I was curious if anyone had any ideas on how I could allow a few different ranges of IP's with the esxcfg-firewall --ipruleAdd command? I am at a loss and am having a hard time locating examples or further documentation about this. Thanks in advance for your help with this.

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• I have a 21TB array but only 16TB is visible from Windows

  - by Relentim

  CONTROLLER Raid Controller: 3Ware 9650SE-24M8 Disks: 21 x 1TB RAID5 Stripe 64KB WINDOWS OS: Windows Server 2003 SP2 32x Disk: Dynamic 19557.44GB Volume: Capacity 15832.19GB I guess my array must have a 4KB block size which is limiting it to 16TB. I think I would have to switch to a 64KB block size to be able to see a maximum of 256TB. Or create another unit on my controller to go above 16TB of storage. Unfortunately I have already added over 16TB, ideally I would like to shrink the array and reclaim the 5 disks that aren't doing anything. I don't think this is possible. More likely, can I change the block size so 20TB becomes visible in windows?

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• What needs updating when moving a bootable Windows 7 (or Vista) partition?

  - by SuperTempel

  When I move a bootable NTFS partition with Windows on it to a different block offset, what needs updating to make it bootable again? In particular, here's what I tried: I have a disk with several partitions, one of which is the NTFS partition with Windows on it, and the disk uses the plain old MBR block 0 for the partitions layout (no more than 4 partitions). Now I format and partition a new, larger, disk. There I make room for the NTFS partition and copy the contents from the old disk's NTFS Windows partition into. And I make the partition "active". However, when I try to boot from this disk, I get a "read error" message immediately and the booting stops, the exact text is: A disk read error occurred Press Ctrl+Alt+Del to restart I verified that both disks have the same boot sector code in block 0. It seems to me that something else might need updating. I guess that somewhere there's a absolute block reference that I need to update, probably pointing to the next level loader or to the NT kernel. Update: I found this article going quite into the depth of what I want to know. However, it says to modify boot.ini, but I have Windows 7 installed here, where such things appear to have changed: No boot.ini but a folder called System Volume Information with GUID and other data in it that sounds related to my problem. Going to keep digging... Update 2: Thanks to the terrible looking but very informative website by starman, I was able to figure out the first step: The NTFS boot sector has a field for "hidden" sectors. This feld has to contain the sector number of the boot sector. This solves the "read error" message. Now, however, I get a "BOOTMGR is missing" error instead. Looks like there's another place where a block number has to be adjusted, but I can't find anything in the code listing about this. I do find a lot of help sites suggesting Windows tools for fixing this "BOOTMGR is missing" problem, but none seem to know what goes on behind the scenes. Kind of like suggesting to re-install Windows when there's a little problem with it. At least, those fixes seem to work, mostly involving the Bcdedit and Bootrec tools. Now, who knows what they do, especially the latter, in regards to a moved partition? Update 3: After lots of trial-and-error attempts, I believe now that the solution lies in the BCD-Template registry file, residing usually inside \Windows\System32\config. If I get this updated using the "bcdboot" command, Windows starts up from it. I am now in the middle of figuring out what information this registry contains relevant to the above question. Any pointers to the contents of this registry are welcome. Update 4: Turns out that while the BCD-Template file gets rewritten and has different binary contents than its predecessor, the values inside do not change. So it must be something else that bcdboot.exe writes. I had previously already checked if it changes the first 32 boot blocks of the partition, but they appear to remain unchanged. Parititon map doesn't get changed, either. So what is it that bcdboot modifies besides the BCD registry? Any tips on how I can trace that? Are there low level tools that show me what files a program writes to? Update 5: The answer seems to be: c:\Boot\BCD is also changed, and that appears to be the key file for the boot manager's process. I'll investigate this later... Update 6: It seems to be an important detail that I had originally two partitions created when I installed Windows 7: A small partition of 204800 sectors which appears to be a bootstrap partition, followed by the actual, large, partition containing the Windows system (drive C:). When I tried to transfer this installation to a new, larger, disk, I had kept the same two partitions intact on the new drive, although they ended up at a different offset. This alone led to the "BOOTMGR is missing" message. Since then, I've used bcdboot.exe only on the Windows partition, which added the \Boot\BCD file on that partition. That file (and folder) did originally only exist on the smaller partition. Hence, this problem may be more complicated in my case as one partition (the boot strapper) referred to another partition (the one containing the OS), whereas other people may only have to deal with one partition containing both, and maybe there the solution is simpler. Update 7: Found one more detail: The \Boot\BCD file records the MBR's serial number. If that number doesn't match, the system won't boot. Next I'll test if there's also an absolute block reference stored in there.

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• XNA: Camera's Rotation and Translation matrices seem to interfere with each other

  - by Danjen

  I've been following the guide here for how to create a custom 2D camera in XNA. It works great, I've implemented it before, but for some reason, the matrix math is throwing me off. public sealed class Camera2D { public Vector2 Origin { get; set; } public Vector2 Position { get; set; } public float Scale { get; set; } public float Rotation { get; set; } } It might be easier to just show you a picture of my problem: http://i.imgur.com/H1l6LEx.png What I want to do is allow the camera to pivot around any given point. Right now, I have the rotations mapped to my shoulder buttons on a gamepad, and if I press them, it should rotate around the point the camera is currently looking at. Then, I use the left stick to move the camera around. The problem is that after it's been rotated, pressing "up" results in it being used relative to the rotation, creating the image above. I understand that matrices have to be applied in a certain order, and that I have to offset the thing to be rotated around the world origin and move it back, but it just won't work! public Matrix GetTransformationMatrix() { Matrix mRotate = Matrix.Identity * Matrix.CreateTranslation(-Origin.X, -Origin.Y, 0.00f) * // Move origin to world center Matrix.CreateRotationZ(MathHelper.ToRadians(Rotation)) * // Apply rotation Matrix.CreateTranslation(+Origin.X, +Origin.Y, 0.00f); // Undo the move operation Matrix mTranslate = Matrix.Identity * Matrix.CreateTranslation(-Position.X, Position.Y, 0.00f); // Apply the actual translation return mRotate * mTranslate; } So to recap, it seems I can have it rotate around an arbitrary point and lose the ability to have "up" move the camera straight up, or I can rotate it around the world origin and have the camera move properly, but not both.

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• Need help transforming DirectX 9 skybox hlsl shader to DirectX 11

  - by J2V

  I am in the middle of implementing a skybox to my game. I have been following this tutorial http://rbwhitaker.wikidot.com/skyboxes-2. I am using MonoGame as a framework and in order to support both Windows and Windows 8 metro I need to compile the shader with pixel and vertex shader 4. compile vs_4_0_level_9_1 compile ps_4_0_level_9_1 However some of the hlsl syntax has been updated with DX10 and DX11. I need to update this hlsl code: float4x4 World; float4x4 View; float4x4 Projection; float3 CameraPosition; Texture SkyBoxTexture; samplerCUBE SkyBoxSampler = sampler_state { texture = <SkyBoxTexture>; magfilter = LINEAR; minfilter = LINEAR; mipfilter = LINEAR; AddressU = Mirror; AddressV = Mirror; }; struct VertexShaderInput { float4 Position : POSITION0; }; struct VertexShaderOutput { float4 Position : POSITION0; float3 TextureCoordinate : TEXCOORD0; }; VertexShaderOutput VertexShaderFunction(VertexShaderInput input) { VertexShaderOutput output; float4 worldPosition = mul(input.Position, World); float4 viewPosition = mul(worldPosition, View); output.Position = mul(viewPosition, Projection); float4 VertexPosition = mul(input.Position, World); output.TextureCoordinate = VertexPosition - CameraPosition; return output; } float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0 { return texCUBE(SkyBoxSampler, normalize(input.TextureCoordinate)); } technique Skybox { pass Pass1 { VertexShader = compile vs_2_0 VertexShaderFunction(); PixelShader = compile ps_2_0 PixelShaderFunction(); } } I quess I need to change Texture into TextureCube, change sampler, swap texCUBE() with TextureCube.Sample() and change PixelShader return semantic to SV_Target0. I'm very new in shader languages and any help is appreciated!

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• IASA Sessions on Social Networking Note Influence of Millennial Generation on Insurance Technology

  - by [email protected]

  Helen Pitts, senior product marketing manager for Oracle Insurance is blogging from the 2010 IASA Annual Conference and Business Show this week. Social networking continues to be a buzzword for many in the industry. Erin Esurance, the Geico Gecko and even Nationwide's "The World's Greatest Spokesperson in the World" all have a prominent presence in the social media world. Sessions at the 2010 IASA Annual Conference and Business Show this week in Grapevine, Texas, highlighted how the millennial generation's exploding use of social media is spurring more carriers to leverage tools like Facebook, LinkedIn and other social networks to engage prospect and customers. While panelists encouraged carriers to leverage social networking tools for marketing and communications, they expressed the need for caution and corporate governance when it comes to using the tools as a part of claims, underwriting, and human resources recruitment business practices, and interactions with producers. (A previous Oracle Insurance blog entry by my colleague Susan Keuer noted that social networking and its impact on the underwriting process was also a hot topic at the recent AHOU conference.) Speaking of the millennial generation, IASA announced a new scholarship program and awarded three scholarships during the association's conference this week. The IASA Insurance Industry Collegiate Scholarship Program awards $2,000 scholarships to students in their second or third year of college who are studying an insurance-related field at a four-year college or university. The IASA scholarship committee is co-chaired by Wendy Gibson, vice president of business development for Oracle Insurance. Gibson, a long time IASA volunteer, is completing her second term on IASA's volunteer management team as vice president of industry relations. Helen Pitts is senior product marketing manager for Oracle Insurance.

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• How to implement RLE into a tilemap?

  - by Smallbro

  Currently I've been using a 3D array for my tiles in a 2D world but the 3D side comes in when moving down into caves and whatnot. Now this is not memory efficient and I switched over to a 2D array and can now have much larger maps. The only issue I'm having now is that it seems that my tiles cannot occupy the same space as a tile on the same z level. My current structure means that each block has its own z variable. This is what it used to look like: map.blockData[x][y][z] = new Block(); however now it works like this map.blockData[x][y] = new Block(z); I'm not sure why but if I decide to use the same space on say the floor below it wont allow me to. Does anyone have any ideas on how I can add a z-axis to my 2D array? I'm using java but I reckon the concept carries across different languages. Edit: As Will posted, RLE sounds like the best method for achieving a fast 3D array. However I'm struggling to understand how I would even start to implement it? Would I create a 4D array the 4th being something which controls how many to skip? Or would the x-axis simply change altogether and have large gaps in between - for example [5][y][z] would skip 5 tiles? Is there something really obvious here which I am missing? The number of z levels I'm trying to have is around 66, it would be preferably that I can have up to or more than 1000 in x and y.

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• Don’t be a dinosaur. Use Calendar Tree!

  - by jamiet

  If one spends long enough in my company one will likely eventually have to listen to me bark on about subscribable calendars. I was banging on about them way back in 2009, I’ve cajoled SQLBits into providing one, provided one myself for the World Cup, and opined that they could be transformative for the delivery of BI. I believe subscribable calendars can change the world but have never been good at elucidating why I thought so, for that reason I always direct people to read a blog by Scott Adams (yes, the guy who draws Dilbert) entitled Calendar as Filter. In that blog post Scott writes: I think the family calendar is the organizing principle into which all external information should flow. I want the kids' school schedules for sports and plays and even lunch choices to automatically flow into the home calendar. Everything you do has a time dimension. If you are looking for a new home, the open houses are on certain dates, and certain houses that fit your needs are open at certain times. If you are shopping for some particular good, you often need to know the store hours. Your calendar needs to know your shopping list and preferences so it can suggest good times to do certain things I think the biggest software revolution of the future is that the calendar will be the organizing filter for most of the information flowing into your life. You think you are bombarded with too much information every day, but in reality it is just the timing of the information that is wrong. Once the calendar becomes the organizing paradigm and filter, it won't seem as if there is so much. I wholly agree and hence was delighted to discover (via the Hanselminutes podcast) that Scott has a startup called CalendarTree.com whose raison d’etre is to solve this very problem. What better way to describe a Scott Adams startup than with a Scott Adams comic: I implore you to check out Calendar Tree and make the world a tiny bit better by using it to share any information that has a time dimension to it. Don’t be a dinosaur, use Calendar tree! @Jamiet

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• Obama’s win and the geeky stuff behind his success

  - by Gopinath

  Mr. Obama is elected as President of United States for the second term with a great majority. Here are few geeky bytes associated with Mr.Obama’s success and the world records he set up Obama Creates New Records on Twitter and Facebook – Just after winning the race for president, Barak Obama setup world records on Twitter & Facebook. His tweet “Four more years” re-tweeted more than 770K times and his Facebook post received 3.8 million likes. Twitter Kills the Fail Whale, One Tweet at a Time – Twitter handled insane user loads with millions of tweets related to election and proved that it’s platform is now more robust than ever. In a post on the company’s engineering blog, Twitter said people sent 31 million election-related tweets on Tuesday alone. From 8:11 p.m. to 9:11 p.m. P.S.T., Twitter processed an average 9,965 tweets per second, with a one-second peak of 15,107 tweets per second at 8:20 p.m., the company said. Obama’s win a big vindication for Nate Silver, king of the quants – Nate Silver, a statistician and blogger was spot on in predicting Obama’s win many weeks. He did not depend on astrology or surveys to predict Obama’s success. He used big data and statistical analysis to project votes. CNET says “Despite some incredulous political pundits, the FiveThirtyEight statistician appears to have correctly predicted the winner in all 50 states in the presidential election” Inside the Secret World of the Data Crunchers Who Helped Obama Win – Team Obama used big data and analytical systems to win the elections!! Barack Obama Goes On Reddit For Last Campaign Stop Of Political Career – Reditt is getting a lot of Obama’s attention these days. He is quite often stopping by Reditt to say hi to the nerds & geeks hanging out there. His chat with nerds on Reddit has paid rich dividends.

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• How do I align my partition table properly?

  - by Jorge Castro

  I am in the process of building my first RAID5 array. I've used mdadm to create the following set up: root@bondigas:~# mdadm --detail /dev/md1 /dev/md1: Version : 00.90 Creation Time : Wed Oct 20 20:00:41 2010 Raid Level : raid5 Array Size : 5860543488 (5589.05 GiB 6001.20 GB) Used Dev Size : 1953514496 (1863.02 GiB 2000.40 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 1 Persistence : Superblock is persistent Update Time : Wed Oct 20 20:13:48 2010 State : clean, degraded, recovering Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 64K Rebuild Status : 1% complete UUID : f6dc829e:aa29b476:edd1ef19:85032322 (local to host bondigas) Events : 0.12 Number Major Minor RaidDevice State 0 8 16 0 active sync /dev/sdb 1 8 32 1 active sync /dev/sdc 2 8 48 2 active sync /dev/sdd 4 8 64 3 spare rebuilding /dev/sde While that's going I decided to format the beast with the following command: root@bondigas:~# mkfs.ext4 /dev/md1p1 mke2fs 1.41.11 (14-Mar-2010) /dev/md1p1 alignment is offset by 63488 bytes. This may result in very poor performance, (re)-partitioning suggested. Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=16 blocks, Stripe width=48 blocks 97853440 inodes, 391394047 blocks 19569702 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=0 11945 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Writing inode tables: ^C 27/11945 root@bondigas:~# ^C I am unsure what to do about "/dev/md1p1 alignment is offset by 63488 bytes." and how to properly partition the disks to match so I can format it properly.

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• SQL SERVER – Concurrency Basics – Guest Post by Vinod Kumar

  - by pinaldave

  This guest post is by Vinod Kumar. Vinod Kumar has worked with SQL Server extensively since joining the industry over a decade ago. Working on various versions from SQL Server 7.0, Oracle 7.3 and other database technologies – he now works with the Microsoft Technology Center (MTC) as a Technology Architect. Let us read the blog post in Vinod’s own voice. Learning is always fun when it comes to SQL Server and learning the basics again can be more fun. I did write about Transaction Logs and recovery over my blogs and the concept of simplifying the basics is a challenge. In the real world we always see checks and queues for a process – say railway reservation, banks, customer supports etc there is a process of line and queue to facilitate everyone. Shorter the queue higher is the efficiency of system (a.k.a higher is the concurrency). Every database does implement this using checks like locking, blocking mechanisms and they implement the standards in a way to facilitate higher concurrency. In this post, let us talk about the topic of Concurrency and what are the various aspects that one needs to know about concurrency inside SQL Server. Let us learn the concepts as one-liners: Concurrency can be defined as the ability of multiple processes to access or change shared data at the same time. The greater the number of concurrent user processes that can be active without interfering with each other, the greater the concurrency of the database system. Concurrency is reduced when a process that is changing data prevents other processes from reading that data or when a process that is reading data prevents other processes from changing that data. Concurrency is also affected when multiple processes are attempting to change the same data simultaneously. Two approaches to managing concurrent data access: Optimistic Concurrency Model Pessimistic Concurrency Model Concurrency Models Pessimistic Concurrency Default behavior: acquire locks to block access to data that another process is using. Assumes that enough data modification operations are in the system that any given read operation is likely affected by a data modification made by another user (assumes conflicts will occur). Avoids conflicts by acquiring a lock on data being read so no other processes can modify that data. Also acquires locks on data being modified so no other processes can access the data for either reading or modifying. Readers block writer, writers block readers and writers. Optimistic Concurrency Assumes that there are sufficiently few conflicting data modification operations in the system that any single transaction is unlikely to modify data that another transaction is modifying. Default behavior of optimistic concurrency is to use row versioning to allow data readers to see the state of the data before the modification occurs. Older versions of the data are saved so a process reading data can see the data as it was when the process started reading and not affected by any changes being made to that data. Processes modifying the data is unaffected by processes reading the data because the reader is accessing a saved version of the data rows. Readers do not block writers and writers do not block readers, but, writers can and will block writers. Transaction Processing A transaction is the basic unit of work in SQL Server. Transaction consists of SQL commands that read and update the database but the update is not considered final until a COMMIT command is issued (at least for an explicit transaction: marked with a BEGIN TRAN and the end is marked by a COMMIT TRAN or ROLLBACK TRAN). Transactions must exhibit all the ACID properties of a transaction. ACID Properties Transaction processing must guarantee the consistency and recoverability of SQL Server databases. Ensures all transactions are performed as a single unit of work regardless of hardware or system failure. A – Atomicity C – Consistency I – Isolation D- Durability Atomicity: Each transaction is treated as all or nothing – it either commits or aborts. Consistency: ensures that a transaction won’t allow the system to arrive at an incorrect logical state – the data must always be logically correct.  Consistency is honored even in the event of a system failure. Isolation: separates concurrent transactions from the updates of other incomplete transactions. SQL Server accomplishes isolation among transactions by locking data or creating row versions. Durability: After a transaction commits, the durability property ensures that the effects of the transaction persist even if a system failure occurs. If a system failure occurs while a transaction is in progress, the transaction is completely undone, leaving no partial effects on data. Transaction Dependencies In addition to supporting all four ACID properties, a transaction might exhibit few other behaviors (known as dependency problems or consistency problems). Lost Updates: Occur when two processes read the same data and both manipulate the data, changing its value and then both try to update the original data to the new value. The second process might overwrite the first update completely. Dirty Reads: Occurs when a process reads uncommitted data. If one process has changed data but not yet committed the change, another process reading the data will read it in an inconsistent state. Non-repeatable Reads: A read is non-repeatable if a process might get different values when reading the same data in two reads within the same transaction. This can happen when another process changes the data in between the reads that the first process is doing. Phantoms: Occurs when membership in a set changes. It occurs if two SELECT operations using the same predicate in the same transaction return a different number of rows. Isolation Levels SQL Server supports 5 isolation levels that control the behavior of read operations. Read Uncommitted All behaviors except for lost updates are possible. Implemented by allowing the read operations to not take any locks, and because of this, it won’t be blocked by conflicting locks acquired by other processes. The process can read data that another process has modified but not yet committed. When using the read uncommitted isolation level and scanning an entire table, SQL Server can decide to do an allocation order scan (in page-number order) instead of a logical order scan (following page pointers). If another process doing concurrent operations changes data and move rows to a new location in the table, the allocation order scan can end up reading the same row twice. Also can happen if you have read a row before it is updated and then an update moves the row to a higher page number than your scan encounters later. Performing an allocation order scan under Read Uncommitted can cause you to miss a row completely – can happen when a row on a high page number that hasn’t been read yet is updated and moved to a lower page number that has already been read. Read Committed Two varieties of read committed isolation: optimistic and pessimistic (default). Ensures that a read never reads data that another application hasn’t committed. If another transaction is updating data and has exclusive locks on data, your transaction will have to wait for the locks to be released. Your transaction must put share locks on data that are visited, which means that data might be unavailable for others to use. A share lock doesn’t prevent others from reading but prevents them from updating. Read committed (snapshot) ensures that an operation never reads uncommitted data, but not by forcing other processes to wait. SQL Server generates a version of the changed row with its previous committed values. Data being changed is still locked but other processes can see the previous versions of the data as it was before the update operation began. Repeatable Read This is a Pessimistic isolation level. Ensures that if a transaction revisits data or a query is reissued the data doesn’t change. That is, issuing the same query twice within a transaction cannot pickup any changes to data values made by another user’s transaction because no changes can be made by other transactions. However, this does allow phantom rows to appear. Preventing non-repeatable read is a desirable safeguard but cost is that all shared locks in a transaction must be held until the completion of the transaction. Snapshot Snapshot Isolation (SI) is an optimistic isolation level. Allows for processes to read older versions of committed data if the current version is locked. Difference between snapshot and read committed has to do with how old the older versions have to be. It’s possible to have two transactions executing simultaneously that give us a result that is not possible in any serial execution. Serializable This is the strongest of the pessimistic isolation level. Adds to repeatable read isolation level by ensuring that if a query is reissued rows were not added in the interim, i.e, phantoms do not appear. Preventing phantoms is another desirable safeguard, but cost of this extra safeguard is similar to that of repeatable read – all shared locks in a transaction must be held until the transaction completes. In addition serializable isolation level requires that you lock data that has been read but also data that doesn’t exist. Ex: if a SELECT returned no rows, you want it to return no. rows when the query is reissued. This is implemented in SQL Server by a special kind of lock called the key-range lock. Key-range locks require that there be an index on the column that defines the range of values. If there is no index on the column, serializable isolation requires a table lock. Gets its name from the fact that running multiple serializable transactions at the same time is equivalent of running them one at a time. Now that we understand the basics of what concurrency is, the subsequent blog posts will try to bring out the basics around locking, blocking, deadlocks because they are the fundamental blocks that make concurrency possible. Now if you are with me – let us continue learning for SQL Server Locking Basics. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Concurrency

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• SQLAuthority News – Download Whitepaper – A Case Study on “Hekaton” against RPM – SQL Server 2014 CTP1

  - by Pinal Dave

  In this new world of social media, apps and mobile devices, we are all now getting impatient. Automatic updates have spoiled few of our habits. When a new feature is released everybody wants to immediately adopt the feature and start using it. Though this is true in the world of apps and smart phones, but it is still not possible in the developer’s world. When new features are around, before we start using it, we need to spend quite a lots of time to understand it and test it. Once we are sold on the feature we refer the feature to our manager and eventually the entire organization makes decisions on upgrading to use the new feature. Similarly, when the new feature of In-Memory OLTP was announced, pretty much every SQL Server DBA wanted to implement that on their server. Through the implementation of the feature is not hard, it is not that easy as well. One has to do proper research about their own environment and workload before implementing this feature. Microsoft has recently released a Case Study on In-Memory OLTP feature. Here is the abstract from the white paper itself. I/O latch can cause session delays that impact application performance. This white paper describes the procedures and common I/O latch issues when migrating to Hekaton in SQL Server 2014. It also includes challenges that occurred during the migration and the performance analysis at different stages.  If you are going to implement In-Memory OLTP database, this is a good case study to refer. Download white paper from here. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, SQLAuthority News, T SQL

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• Future direction for a developer who is expert in latest software technologies…

  - by Muaz Khan

  Hi everyone, If a (new-coming) developer that learns latest technologies as well as can develop amazing stuff with those technologies and did Bachelors in Arts (BA). So what ’ll be the future of this kind of developer? I meant did he can get good job without degree? I think (but it is the universal truth that) no one (org or company) permit these kind of developers to join them because degree is must for job!! I’m worried about why the world depends upon degree? Why degree is necessary for good job? If a developer has a good experience, why he cannot be able to get good job without degree? What is the future of developer that starts his life as a freelancer and learns everything himself with the help of online available resources? Why companies prerequisite the degree for a good job? A developer without degree can be expert than that who have a degree of MSC etc. Because in 3rd world countries especially Pakistan, a BSC level student taught VB6 and the MSC level student learns C/C++. The common student doesn’t know about latest innovative technologies and he think that the world is depending upon VB6 or C/C++. What is the comparison of that students with a developer that do Bachelors in Arts but know (and can do well with) latest technologies.

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• Free Windows Azure event next Monday in London (29th March)

  - by Eric Nelson

  I just heard that we still have spaces for this event happening next week (29th March 2010). Whilst the event is designed for start-ups, I’m sure nobody would notice if you snuck in :-) Just keep it to yourself ;-) Register using invitation code: 79F2AB. Hope to see you there. The agenda is looking pretty swish: 09:00 – 09:30 Registration 09:30 - 10:15 Keynote  ‘I’ve looked at clouds from both sides now....’– John Taysom, Active Seed Investor 10:15 - 10:45   The Microsoft Vision for Cloud Computing – Steve Clayton, Director Software + Services, EMEA 10:45 - 11:00   Break 11:00 - 12:30 “Windows Azure in Real World” – hear from startups that have built their business around the Azure platform, moderated by Alistair Beagley, Azure UK Developer and Platform Lead 12:30 - 13:15 Lunch and networking  13:15 - 14:15  Breakout Tracks, moderated by our Azure Experts 1. Windows Azure Technical Overview - David Gristwood, Application Architect, Microsoft 2. SQL Azure Technical Overview – Eric Nelson, Application Architect, Microsoft 3. Commercial insight into Windows Azure and what this means for BizSpark Start-ups - Simon Karn, Commercial Lead, UK Windows Azure Incubation Team, Microsoft 14:15 - 14:30 Session change over 14:30 - 15:30   Breakout Tracks, moderated by our Azure Experts 1. SQL Azure Technical Overview (repeat) - Eric Nelson, Application Architect, Microsoft 2. Deep dive into Windows Azure – Neil Kidd, Architect, Microsoft Technology Centre 3. Lessons Learnt - Windows Azure in the Real World interactive session – Two customers hosted by Matt Deacon, Enterprise Architect, Microsoft 15:30 - 16:00 Break & Session change over 16:00 - 17:00 Breakout Tracks, moderated by our Azure Experts 1. PHP / Ruby on Azure Simon Davies, Architect, UK Windows Azure Incubation Team, Microsoft 2. Commercial insight into Windows Azure and what this means for BizSpark Start-ups (repeat) - Simon Karn, Commercial Lead, UK Windows Azure Incubation Team, Microsoft 3. Lessons Learnt - Windows Azure in the Real World interactive session #2 Two customers hosted by Matt Deacon, Enterprise Architect, Microsoft 17:00 - 18:00 Pitches and Judging 18:15 Wrap-up and close 18:15 - 20:00 Drinks & Networking

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• Does HTML 5 &ldquo;Rich vs. Reach&rdquo; a False Choice?

  - by andrewbrust

  The competition between the Web and proprietary rich platforms, including Windows, Mac OS, iPhone/iPad, Adobe’s Flash/AIR and Microsoft’s Silverlight, is not new. But with the emergence of HTML 5 and imminent support for it in the next release of the major Web browsers, the battle is heating up. And with the announcements made Wednesday at Google's I/O conference, it's getting kicked up yet another notch. The impact of this platform battle on companies in the media and advertising world, and the developers who serve them, is significant. The most prominent question is whether video and rich media online will shift towards pure HTML and away from plug-ins like Flash and Silverlight. In fact, certain features in HTML 5 make it suitable for development for line of business applications as well, further threatening those plug-in technologies. So what's the deal? Is this real or hype? To answer that question, I've done my own research into HTML 5's features and talked to several media-focused, New York area developers to get their opinions. I present my findings to you in this post. Before bearing down into HTML 5 specifics and practitioners’ quotes, let's set the context. To understand what HTML 5 can do, take a look at this video of Sports Illustrated’s HTML 5 prototype. This should start to get you bought into the idea that HTML 5 could be a game-changer. Next, if you happen to have installed the beta version of Google's Chrome 5 browser, take a look at the page linked to below, and in that page, click on any of the game thumbnails to see what's possible, without a plug-in, in this brave new world. (Note, although the instructions for each game tell you to press the A key to start, press the Z key instead.). Here's the link: http://www.kesiev.com/akihabara As an adjunct to what's enabled by HTML 5, consider the various transforms that are part of CSS 3. If you're running Safari as your browser, the following link will showcase this live; if not, you'll see a bitmap that will give you an idea of what's possible: http://webkit.org/blog/386/3d-transforms Are you starting to get the picture (literally)? What has up until now required browser plug-ins and other patches to HTML, most typically Flash, will soon be renderable, natively, in all major browsers. Moreover, it's looking likely that developers will be able to deliver such content and experiences in these browsers using one base of markup and script code (using straight JavaScript and/or jQuery), without resorting to browser-specific code and workarounds. If you're skeptical of this, I wouldn't blame you, especially with respect to Microsoft's Internet Explorer. However, i can tell you with confidence that even Microsoft is dedicated to full-on HTML 5 support in version 9 of that browser, which is currently under development. So what’s new in HTML 5, specifically, that makes sites like this possible?  The specification documents go into deep detail, and there’s no sense in rehashing them here, but a summary is probably in order.   Here is a non-authoritative, but useful, list of the major new feature areas in HTML 5: 2D drawing capabilities and 3D transforms. 2D drawing instructions can be embedded statically into a Web page; application interactivity and animation can be achieved through script.  As mentioned above, 3D transforms are technically part of version 3 of the CSS (Cascading Style Sheets) spec, rather than HTML 5, but they can nonetheless be thought of as part of the bundle.  They allow for rendering of 3D images and animations that, together with 2D drawing, make HTML-based games much more feasible than they are presently, as the links above demonstrate. Embedded audio and video. A media player can appear directly in a rendered Web page, using HTML markup and no plug-ins. Alternately, player controls can be hidden and the content can play automatically. Major enhancements to form-based input. This includes such things as specification of required fields, embedding of text “hints” into a control, limiting valid input on a field to dates, email addresses or a list of values.  There’s more to this, but the gist is that line-of-business applications, with complicated input and data validation, are supported directly Offline caching, local storage and client-side SQL database. These facilities allow Web applications to function more like native apps, even if no internet connection is available. User-defined data. Data (or metadata – data about data) can easily be embedded statically and/or retrieved and updated with Javascript code. This avoids having to embed that data in a separate file, or within script code. Taken together, these features position HTML to compete with, and perhaps overtake, Adobe’s Flash/AIR (and Microsoft’s Silverlight) as a viable Web platform for media, RIAs (rich internet applications – apps that function more like desktop software than Web sites) and interactive Web content, including games. What do players in the media world think about this?  From the embedded video above, we know what Sports Illustrated (and, therefore, Time Warner) think.  Hulu, the major Internet site for broadcast TV content, is on record as saying HTML5 video does not pass muster with them, at least not yet.  YouTube, on the other hand, already has an experimental HTML 5-based version of their site.  TechCrunch has reported that NetFlix is flirting with HTML 5 too, especially as it pertains to embedded browsers in TV-based devices.  And the New York Times’ Web site now embeds some video clips without resorting to Flash.  They have to – otherwise iPhone, iPod Touch and iPad users couldn’t see them in the Mobile Safari browser. What do media-focused developers think about all this?  I talked to several to get their opinions. Michael Pinto is CEO and Founder of Very Memorable Design whose primary focus has been to help marketing directors get traction online.  The firm’s client roster includes the likes Time, Inc., Scholastic and PBS.  Pinto predicts that “More and more microsites that were done entirely in Flash will be done more and more using jQuery. I can also see slideshows and video now being done without Flash. However if you needed to create a game or highly interactive activity Flash would still be the way to go for the web.” A dissenting view comes from Jesse Erlbaum, CEO of The Erlbaum Group, LLC, which serves numerous clients in the magazine publishing sector.  When I asked Erlbaum whether he thought HTML 5 and jQuery/JavaScript would steal significant market share from Flash, he responded “Not at all!  In particular, not for media and advertising customers!  These sectors are not generally in the business of making highly functional applications, which is the one place where HTML5/jQuery/etc really shines.” Ironically, Pinto’s firm is a heavy user of Flash for its projects and Erlbaum’s develops atop the “LAMP” (Linux, Apache, MySQL and PHP/Perl) stack.  For whatever reason, each firm seems to see the other’s toolset as a more viable choice.  But both agree that the developer tool story around HTML 5 is deficient.  Pinto explains “What’s lost with [HTML 5 and Javascript] techniques is that there isn’t a single widely favored easy-to-use tool of choice for authoring. So with Flash you can get up and running right away and not worry about what is different from one browser to the next.“  Erlbaum agrees, saying: “HTML5/Javascript lacks a sophisticated integrated development environment (IDE) which is an essential part of Flash.  If what someone is trying to make is primarily animation, it's a waste of time…to do this in Javascript.  It can be done much more easily in Flash, and with greater cross-browser compatibility and consistency due to the ubiquity of Flash.” Adobe (maker of Flash since its 2005 acquisition of Macromedia) likely agrees.  And for better or worse, they’ve decided to address this shortcoming of HTML 5, even at risk of diminishing their Flash platfrom. Yesterday Adobe announced that their hugely popular Deamweaver Web design authoring tool would directly support HTML 5 and CSS 3 development.  In fact, the Adobe Dreamweaver CS5 HTML5 Pack is downloadable now from Adobe Labs. Maybe Adobe is bowing to pressure from ardent Web professionals like Scott Kellum, Lead Designer at Channel V Media,  a digital and offline branding firm, serving the media and marketing sectors, among others.  Kellum told me that HTML 5 “…will definitely move people away from Flash. It has many of the same functionalities with faster load times and better accessibility. HTML5 will help Flash as well: with the new caching methods you can now even run Flash apps offline.” Although all three Web developers I interviewed would agree that Flash is still required for more sophisticated applications, Kellum seems to have put his finger on why HTML 5 may nonetheless dominate.  In his view, much of the Web development out there has little need for high-end capabilities: “Most people want to add a little punch to a navigation bar or some video and now you can get the biggest bang for your buck with HTML5, CSS3 and Javascript.” I’ve already mentioned that Google’s ongoing I/O conference, at the Moscone West center in San Francisco, is driving the HTML 5 news cycle, big time.  And Google made many announcements of their own, including the open sourcing of their VP8 video codec, new enterprise-oriented capabilities for its App Engine cloud offering, and the creation of the Chrome Web Store, which the company says will make it easier to find and “install” Web applications, in a fashion similar to  the way users procure native apps on various mobile platforms. HTML 5 looks to be disruptive, especially to the media world.  And even if the technology ends up disappointing, the chatter around it alone is causing big changes in the technology world.  If the richness it promises delivers, then magazine publishers and non-text digital advertisers may indeed have a platform for creating compelling content that loads quickly, is standards-based and will render identically in (the newest versions of) all major Web browsers.  Can this development in the digital arena save the titans of the print world?  I can’t predict, but it’s going to be fun to watch, and the competitive innovation from all players in both industries will likely be immense.

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• CodePlex Daily Summary for Monday, March 29, 2010

  CodePlex Daily Summary for Monday, March 29, 2010New ProjectsBUtil: Backup toolcfDateTime: A library for conveniant dealing with date and time in code and UI.ComplexNetwork: Complex network is a network (graph) with non-trivial topological features—features that do not occur in simple networks such as lattices or random...Crash, Burn, Learn AI: Crash, Burn, Learn AI is a "social" AI that tries to learn a language. You provide it with words and it tries to speak.DashboardNET: Student project for Database Applications classDawf: Dual Audio Workflow: Dawf (Dual Audio Workflow) is a script for Sony Vegas Pro and PluralEyes. First, use PluralEyes to sync good audio from an external recorder (for ...EFDataPager: The EFDataPager is an Web User Control that provides Entity Framework data paging. This control enables your ListView, Datagrid or other data pres...GALOAP: GALOAP is a web framework for developing games with a purpose (or GWAP). A GWAP is a game played on a computer that serves some purpose for the peo...Modular CSharp Web Server: The Modular CSharp Web Server Is a small web server core that modules can be build to expand it.NHibernate Membership Provider: The NHMemberProvider is a complete .Net Membership Provider developed in C# and utilizing NHibernate for data persistence. NTP-VoIP Chat: NTP-VoIP chat is a sample VoIP based chat client (and server) developed for academic purposes at the Faculty of Electrical Engineering in Sarajevo....SharePoint Labs: SPLabs is a set of labs, either VB.NET or C#, focused on SharePoint technologies. Each lab is in itself a tutorial to learn a specific area of Shar...SharePoint Navigation Menu: Have a Web App with multiple site collections and need a common navigation menu? How about a SP Web Part that gives a consistent, easy to use, cen...Smebedor — greatest e-shop in the world: Smebedor - greatest e-shop in the worldStarksoft FTP and FTPS C# Client Library: Free, open source and easy to use .NET 2.0+ / Mono 2.x Component for connecting to FTP servers. Explicit and implicit SSL and TLS connections, dat...Sweet Office: The so Sweet Office built on the so sweet Silverlight.World Map WebPart: Display a world map and points several locations configured in the web part properties. The map is based on Google Maps and Live Maps.New ReleasesActivate Your Glutes: v1.0.2.0: An admin section has been added to the site and the log4net framework has been integrated. Minor tweak to registration to present a better date pic...ArkSwitch: ArkSwitch v1.1.4: Bugfix release, mainly for the new process mode.BatterySaver: Version 0.3: ChangeLog Add support for power change events in standby/hibernate (Issue) Add support for multiple configuration profiles (Issue) Added XSD for co...BUtil: BUtil 4.7: The initial releasecfDateTime: cfDateTime 0.1.1.3: This is the first public release of cfDateTime. Supported Features are: Base-implementation of the DateTimeSpan-type which is the logic-holder Im...Crash, Burn, Learn AI: Crash, Burn, Learn v0.1 Alpha: The first version of the AI. Got basic functionality but not everything works as it should so you're very welcome to test :)CycleMania Starter Kit EAP - ASP.NET 4 Problem - Design - Solution: Cyclemania 0.08.43: See Source Code tab for recent change history.Dawf: Dual Audio Workflow: Beta: Beta for DawfeCommerce by Onex Community Edition: Installer of eCommerce by Onex Community 1.0: Installer of eCommerce by Onex Community 1.0 Last changes: Added integration with Paypal Corrected of adding photos and attachments to products ...Encrypted Notes: Encrypted Notes 1.6.1: This is the latest version of Encrypted Notes (1.6.1), with bug fixes (mainly One-Time Pad). It has an installer - it will create a directory 'CPas...ExtAspNet: ExtAspNet v2.2.1: ExtAspNet v2.2.1 ExtAspNet is a set of professional Asp.net controls with native AJAX support and rich UI effect which aim at No JavaScript, No C...Load Test User Mock Toolkits: Open.LoadTest.User.Mock.Toolkits 1.0: 此版本为非正式版本，未对性能方面进行优化。而且框架正在重构调整中。miniTodo: mini Todo version 0.1: 超簡易TodoアプリMsmqJava: MsmqJava v1.2: MsmqJava v1.2 is an update of the Java/JNI wrapper for MSMQ. It is currently at v1.2.1.2. Last updated 28 March 2010. This version includes: ...N2 CMS: 2.0 beta2: Major Changes 2.0b-2.0b2 bugfixes prettified home interface analytics part icons for file types Major Changes 1.5-2.0b ASP.NET MVC 2 templat...New York Times Silverlight Kit: Version 1.0 for Windows Phone 7 Series: New York Times Silverlight Kit for Windows Phone 7 Series Release NotesDoes not include Articles or TimesTag APIsNHibernate Membership Provider: NHibernate Membership Provider 0.9b: This is the initial source code release of NHibernateProvider. I'm putting this up in beta for now, although it is currently being used in one of ...PowerShell ISE-Cream: PSISECream 0.1: So far, you must have downloaded the source code from this project and used the individual modules or scripts for different ISE addons. This projec...Prolog.NET: Prolog.NET 1.0 Beta 2: Installer includes: primary Prolog.NET assembly Prolog.NET Workbench Prolog.NET Scheduler sample application PrologTest console applicati...QuickStart Engine (3D Game Engine for XNA): QuickStart Engine v0.21: Main FeaturesClean engine architecture Makes it easy to make your own game using the engine. Messaging system allows you to communicate between s...S3Appender (Appender for Log4Net that Uses Amazon S3 For Storing Log Files): Stable Release 0.5: Download directly from source code http://s3appender.codeplex.com/SourceControl/changeset/view/43435SharePoint Labs: SPLab5001A-FRA-Level100: SPLab5001A-FRA-Level100 This SharePoint Lab will teach you how to increase your knowledge and use of CAML within Visual Studio. Lab Language : Fren...SharePoint Navigation Menu: spNavigationMenu 1.0: Inital release.Sweet Office: Simple drawing 0.0.1: A Visio-like simple drawing tool was built. Sweet Office is a Office-like tool set running on Silverlight.Switch Checker: v1.0.0.4 - Improved functionality: Added features: Add edit and delete options to right click switch list. Allow delete multiple switches from edit switches form. Allow copy MAC ...System.Common: System.Common Library: First release of System.Common.dlTeam 12 - Team FTW - Software Project: Quadrisauce Alpha Release: This is the first release of Quadrisauce!Visual Studio DSite: Math Wiz Quiz (Visual Basic 2008): A simple math quiz program, that test your knowledge of addition, subtraction and multiplication. This quiz is aimed for elementary kids, but you ...World Map WebPart: World Map Web Part v1.0: Display a world map and points several locations configured in the web part properties. The web part is using either Google Maps or Live Maps depen...WPF Dialogs: Version 0.2.0: 4 New Dialogs: NewFolderDialog / NewFolderDialog - Deutsch DeleteDialog / DeleteDialog - Deutsch] SaveDialog / SaveDialog- Deutsch RenamerDia...WPF Dialogs: Version 0.2.0 for .Net 3.5: The same new features like in the .Net 4 version Version 0.2.0ニコ生タイピング: Niconama Typing Ver. 10-03-28: ランキング 同順位の表示方法を変更 ランキング表示にスクロールバーを追加 切断ボタンを追加 スピードを5倍まで選択できるように変更 ニコ生の仕様変更に対応（運営コメント） デバッグ部分UI変更 NGワードを含む名前は登録できないように変更（含む場合、「名無し（NGコメ）...Most Popular ProjectsRawrWBFS ManagerASP.NET Ajax LibraryMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitAJAX Control ToolkitLiveUpload to FacebookWindows Presentation Foundation (WPF)ASP.NETMicrosoft SQL Server Community & SamplesMost Active ProjectsRawrjQuery Library for SharePoint Web ServicesManaged Extensibility FrameworkLINQ to TwitterMicrosoft Biology FoundationBlogEngine.NETpatterns & practices: Composite WPF and SilverlightFarseer Physics EngineTable2ClassNB_Store - Free DotNetNuke Ecommerce Catalog Module

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• How do you deal with translating theory into practice?

  - by Mr. Shickadance

  Hello all! Being a computer scientist in a research field I am often tasked with working alongside professionals outside of the software domain (think math people, electrical engineer etc), and then translating their theories and ideas into real-world implementations. I often find it difficult when they present a theoretical problem which appears to be somewhat disconnected from reality. I am not saying that the theory is bogus, only that it is difficult to translate into real-world situations. For example, recently I have been working with software defined radios. We are exploring many different areas, but often the math specialists in my group would present a problem which is heavily grounded in theory (signal processing, physics, whatever). I often struggle at times where it is hard to draw direct parallels between the theory and the real-world implementation that I need to develop. Say we are working on an energy detector, the theory person in my group would say "you need to measure the noise variance with no signal present." This leads me to think "how the hell do I isolate noise from a signal in reality?" There are many examples, but I hope you see where I am going. So, my question is how does one deal with implementation of theoretical concepts when the theory seems detached from reality? Or at least when the connections are not so clear. Or perhaps, the person with the 'theory' may be ignorant of real restrictions? Note: I found this to be a hard question to ask - hopefully you are following me. If you have suggestions on how I could improve it, by all means let me know! Thanks for looking! EDIT: To be a bit more clear, I understand in situations like this that I must learn that specific domain myself to an extent (i.e. signal processing), but I am more concerned with when those theoretical concepts do not appear to be as grounded in practice as one would like.

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• Evil DRY

  - by StefanSteinegger

  DRY (Don't Repeat Yourself) is a basic software design and coding principle. But there is just no silver bullet. While DRY should increase maintainability by avoiding common design mistakes, it could lead to huge maintenance problems when misunderstood. The root of the problem is most probably that many developers believe that DRY means that any piece of code that is written more then once should be made reusable. But the principle is stated as "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system." So the important thing here is "knowledge". Nobody ever said "every piece of code". I try to give some examples of misusing the DRY principle. Code Repetitions by Coincidence There is code that is repeated by pure coincidence. It is not the same code because it is based on the same piece of knowledge, it is just the same by coincidence. It's hard to give an example of such a case. Just think about some lines of code the developer thinks "I already wrote something similar". Then he takes the original code, puts it into a public method, even worse into a base class where none had been there before, puts some weird arguments and some if or switch statements into it to support all special cases and calls this "increasing maintainability based on the DRY principle". The resulting "reusable method" is usually something the developer not even can give a meaningful name, because its contents isn't anything specific, it is just a bunch of code. For the same reason, nobody will really understand this piece of code. Typically this method only makes sense to call after some other method had been called. All the symptoms of really bad design is evident. Fact is, writing this kind of "reusable methods" is worse then copy pasting! Believe me. What will happen when you change this weird piece of code? You can't say what'll happen, because you can't understand what the code is actually doing. So better don't touch it anymore. Maintainability just died. Of course this problem is with any badly designed code. But because the developer tried to make this method as reusable as possible, large parts of the system get dependent on it. Completely independent parts get tightly coupled by this common piece of code. Changing on the single common place will have effects anywhere in the system, a typical symptom of too tight coupling. Without trying to dogmatically (and wrongly) apply the DRY principle, you just had a system with a weak design. Now you get a system which just can't be maintained anymore. So what can you do against it? When making code reusable, always identify the generally reusable parts of it. Find the reason why the code is repeated, find the common "piece of knowledge". If you have to search too far, it's probably not really there. Explain it to a colleague, if you can't explain or the explanation is to complicated, it's probably not worth to reuse. If you identify the piece of knowledge, don't forget to carefully find the place where it should be implemented. Reusing code is never worth giving up a clean design. Methods always need to do something specific. If you can't give it a simple and explanatory name, you did probably something weird. If you can't find the common piece of knowledge, try to make the code simpler. For instance, if you have some complicated string or collection operations within this code, write some general-purpose operations into a helper class. If your code gets simple enough, its not so bad if it can't be reused. If you are not able to find anything simple and reasonable, copy paste it. Put a comment into the code to reference the other copies. You may find a solution later. Requirements Repetitions by Coincidence Let's assume that you need to implement complex tax calculations for many countries. It's possible that some countries have very similar tax rules. These rules are still completely independent from each other, since every country can change it of its own. (Assumed that this similarity is actually by coincidence and not by political membership. There might be basic rules applying to all European countries. etc.) Let's assume that there are similarities between an Asian country and an African country. Moving the common part to a central place will cause problems. What happens if one of the countries changes its rules? Or - more likely - what happens if users of one country complain about an error in the calculation? If there is shared code, it is very risky to change it, even for a bugfix. It is hard to find requirements to be repeated by coincidence. Then there is not much you can do against the repetition of the code. What you really should consider is to make coding of the rules as simple as possible. So this independent knowledge "Tax Rules in Timbuktu" or wherever should be as pure as possible, without much overhead and stuff that does not belong to it. So you can write every independent requirement short and clean. DRYing try-catch and using Blocks This is a technical issue. Blocks like try-catch or using (e.g. in C#) are very hard to DRY. Imagine a complex exception handling, including several catch blocks. When the contents of the try block as well as the contents of the individual catch block are trivial, but the whole structure is repeated on many places in the code, there is almost no reasonable way to DRY it. try { // trivial code here using (Thingy thing = new thingy) { //trivial, but always different line of code } } catch(FooException foo) { // trivial foo handling } catch (BarException bar) { // trivial bar handling } catch { // trivial common handling } finally { // trivial finally block } The key here is that every block is trivial, so there is nothing to just move into a separate method. The only part that differs from case to case is the line of code in the body of the using block (or any other block). The situation is especially interesting if the many occurrences of this structure are completely independent: they appear in classes with no common base class, they don't aggregate each other and so on. Let's assume that this is a common pattern in service methods within the whole system. Examples of Evil DRYing in this situation: Put a if or switch statement into the method to choose the line of code to execute. There are several reasons why this is not a good idea: The close coupling of the formerly independent implementation is the strongest. Also the readability of the code and the use of a parameter to control the logic. Put everything into a method which takes a delegate as argument to call. The caller just passes his "specific line of code" to this method. The code will be very unreadable. The same maintainability problems apply as for any "Code Repetition by Coincidence" situations. Enforce a base class to all the classes where this pattern appears and use the template method pattern. It's the same readability and maintainability problem as above, but additionally complex and tightly coupled because of the base class. I would call this "Inheritance by Coincidence" which will not lead to great software design. What can you do against it: Ideally, the individual line of code is a call to a class or interface, which could be made individual by inheritance. If this would be the case, it wouldn't be a problem at all. I assume that it is no such a trivial case. Consider to refactor the error concept to make error handling easier. The last but not worst option is to keep the replications. Some pattern of code must be maintained in consistency, there is nothing we can do against it. And no reason to make it unreadable. Conclusion The DRY-principle is an important and basic principle every software developer should master. The key is to identify the "pieces of knowledge". There is code which can't be reused easily because of technical reasons. This requires quite a bit flexibility and creativity to make code simple and maintainable. It's not the problem of the principle, it is the problem of blindly applying a principle without understanding the problem it should solve. The result is mostly much worse then ignoring the principle.

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• Switching from Java/Java EE career path to C POS path?

  - by Muhammad

  I am a Java/Java EE Developer with about 3 years in this field. I like low-level programming so much... I favor back-end code over front-end. I've a knowledge in C and know little about C++. I got an offer to work with C in Point-of-Sale Payment terminals. I don't know much about how POS works (IDE/toolsets, etc). although I have a payment experience (ISO8583, etc...) I need you own opinion from Switching from the Java's High-level world to POS low-level world Although I love low-level world, but I am afraid from not being found what I seek.. I know programmers are not measured by the tools they use (including prog. langs.) but with their minds. I need your opinions of: Is programming POS terminals in C is an interesting thing, or I'll find myself doing usual code-writing job? (especially I am about to switch my whole career path). I find myself writing an elegant code in Java (like: Sobat http://code.google.com/p/sobat/) a code where I find myself in... So do I'll find the same thing in POS C? or It will all about Libraries that I'll call to finish my work?! Lastly, does this thing worse adventure with my current career (stability, conference, etc.. )? (as I currently don't think to move to a new job) Thanks.

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• Metro: Dynamically Switching Templates with a WinJS ListView

  - by Stephen.Walther

  Imagine that you want to display a list of products using the WinJS ListView control. Imagine, furthermore, that you want to use different templates to display different products. In particular, when a product is on sale, you want to display the product using a special “On Sale” template. In this blog entry, I explain how you can switch templates dynamically when displaying items with a ListView control. In other words, you learn how to use more than one template when displaying items with a ListView control. Creating the Data Source Let’s start by creating the data source for the ListView. Nothing special here – our data source is a list of products. Two of the products, Oranges and Apples, are on sale. (function () { "use strict"; var products = new WinJS.Binding.List([ { name: "Milk", price: 2.44 }, { name: "Oranges", price: 1.99, onSale: true }, { name: "Wine", price: 8.55 }, { name: "Apples", price: 2.44, onSale: true }, { name: "Steak", price: 1.99 }, { name: "Eggs", price: 2.44 }, { name: "Mushrooms", price: 1.99 }, { name: "Yogurt", price: 2.44 }, { name: "Soup", price: 1.99 }, { name: "Cereal", price: 2.44 }, { name: "Pepsi", price: 1.99 } ]); WinJS.Namespace.define("ListViewDemos", { products: products }); })(); The file above is saved with the name products.js and referenced by the default.html page described below. Declaring the Templates and ListView Control Next, we need to declare the ListView control and the two Template controls which we will use to display template items. The markup below appears in the default.html file: <!-- Templates --> <div id="productItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="product"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> </div> <div id="productOnSaleTemplate" data-win-control="WinJS.Binding.Template"> <div class="product onSale"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> </div> <!-- ListView --> <div id="productsListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.products.dataSource, layout: { type: WinJS.UI.ListLayout } }"> </div> In the markup above, two Template controls are declared. The first template is used when rendering a normal product and the second template is used when rendering a product which is on sale. The second template, unlike the first template, includes the text “(On Sale!)”. The ListView control is bound to the data source which we created in the previous section. The ListView itemDataSource property is set to the value ListViewDemos.products.dataSource. Notice that we do not set the ListView itemTemplate property. We set this property in the default.js file. Switching Between Templates All of the magic happens in the default.js file. The default.js file contains the JavaScript code used to switch templates dynamically. Here’s the entire contents of the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { var productsListView = document.getElementById("productsListView"); productsListView.winControl.itemTemplate = itemTemplateFunction; });; } }; function itemTemplateFunction(itemPromise) { return itemPromise.then(function (item) { // Select either normal product template or on sale template var itemTemplate = document.getElementById("productItemTemplate"); if (item.data.onSale) { itemTemplate = document.getElementById("productOnSaleTemplate"); }; // Render selected template to DIV container var container = document.createElement("div"); itemTemplate.winControl.render(item.data, container); return container; }); } app.start(); })(); In the code above, a function is assigned to the ListView itemTemplate property with the following line of code: productsListView.winControl.itemTemplate = itemTemplateFunction;   The itemTemplateFunction returns a DOM element which is used for the template item. Depending on the value of the product onSale property, the DOM element is generated from either the productItemTemplate or the productOnSaleTemplate template. Using Binding Converters instead of Multiple Templates In the previous sections, I explained how you can use different templates to render normal products and on sale products. There is an alternative approach to displaying different markup for normal products and on sale products. Instead of creating two templates, you can create a single template which contains separate DIV elements for a normal product and an on sale product. The following default.html file contains a single item template and a ListView control bound to the template. <!-- Template --> <div id="productItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="product" data-win-bind="style.display: onSale ListViewDemos.displayNormalProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> <div class="product onSale" data-win-bind="style.display: onSale ListViewDemos.displayOnSaleProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> </div> <!-- ListView --> <div id="productsListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.products.dataSource, itemTemplate: select('#productItemTemplate'), layout: { type: WinJS.UI.ListLayout } }"> </div> The first DIV element is used to render a normal product: <div class="product" data-win-bind="style.display: onSale ListViewDemos.displayNormalProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> The second DIV element is used to render an “on sale” product: <div class="product onSale" data-win-bind="style.display: onSale ListViewDemos.displayOnSaleProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> Notice that both templates include a data-win-bind attribute. These data-win-bind attributes are used to show the “normal” template when a product is not on sale and show the “on sale” template when a product is on sale. These attributes set the Cascading Style Sheet display attribute to either “none” or “block”. The data-win-bind attributes take advantage of binding converters. The binding converters are defined in the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll(); } }; WinJS.Namespace.define("ListViewDemos", { displayNormalProduct: WinJS.Binding.converter(function (onSale) { return onSale ? "none" : "block"; }), displayOnSaleProduct: WinJS.Binding.converter(function (onSale) { return onSale ? "block" : "none"; }) }); app.start(); })(); The ListViewDemos.displayNormalProduct binding converter converts the value true or false to the value “none” or “block”. The ListViewDemos.displayOnSaleProduct binding converter does the opposite; it converts the value true or false to the value “block” or “none” (Sadly, you cannot simply place a NOT operator before the onSale property in the binding expression – you need to create both converters). The end result is that you can display different markup depending on the value of the product onSale property. Either the contents of the first or second DIV element are displayed: Summary In this blog entry, I’ve explored two approaches to displaying different markup in a ListView depending on the value of a data item property. The bulk of this blog entry was devoted to explaining how you can assign a function to the ListView itemTemplate property which returns different templates. We created both a productItemTemplate and productOnSaleTemplate and displayed both templates with the same ListView control. We also discussed how you can create a single template and display different markup by using binding converters. The binding converters are used to set a DIV element’s display property to either “none” or “block”. We created a binding converter which displays normal products and a binding converter which displays “on sale” products.

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• Improving SpriteBatch performance for tiles

  - by Richard Rast

  I realize this is a variation on what has got to be a common question, but after reading several (good answers) I'm no closer to a solution here. So here's my situation: I'm making a 2D game which has (among some other things) a tiled world, and so, drawing this world implies drawing a jillion tiles each frame (depending on resolution: it's roughly a 64x32 tile with some transparency). Now I want the user to be able to maximize the game (or fullscreen mode, actually, as its a bit more efficient) and instead of scaling textures (bleagh) this will just allow lots and lots of tiles to be shown at once. Which is great! But it turns out this makes upward of 2000 tiles on the screen each time, and this is framerate-limiting (I've commented out enough other parts of the game to make sure this is the bottleneck). It gets worse if I use multiple source rectangles on the same texture (I use a tilesheet; I believe changing textures entirely makes things worse), or if you tint the tiles, or whatever. So, the general question is this: What are some general methods for improving the drawing of thousands of repetitive sprites? Answers pertaining to XNA's SpriteBatch would be helpful but I'm equally happy with general theory. Also, any tricks pertaining to this situation in particular (drawing a tiled world efficiently) are also welcome. I really do want to draw all of them, though, and I need the SpriteMode.BackToFront to be active, because

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• Get to Know a Candidate (15 of 25): Jerry White&ndash;Socialist Equality Party

  - by Brian Lanham

  DISCLAIMER: This is not a post about “Romney” or “Obama”. This is not a post for whom I am voting. Information sourced for Wikipedia. White (born Jerome White) is an American politician and journalist, reporting for the World Socialist Web Site.  White's Presidential campaign keeps four core components: * International unity in the working class * Social equality * Opposition to imperialist militarism and assault on democratic rights * Opposition to the political subordination of the working class to the Democrats and Republicans The White-Scherrer ticket is currently undergoing a review by the Wisconsin election committee concerning the ballot listing of the party for the 2012 Presidential elections. White has visited Canada, Germany, and Sri Lanka to campaign for socialism and an international working class movement. The Socialist Equality Party (SEP) is a Trotskyist political party in the United States, one of several Socialist Equality Parties around the world affiliated to the International Committee of the Fourth International (ICFI). The ICFI publishes daily news articles, perspectives and commentaries on the World Socialist Web Site. The party held public conferences in 2009 and 2010. It led an inquiry into utility shutoffs in Detroit, Michigan earlier in 2010, after which it launched a Committee Against Utility Shutoffs. Recently it sent reporters to West Virginia to report on the Upper Big Branch Mine disaster and the way that Massey Energy has treated its workers. It also sent reporters to the Gulf Coast to report on the Deepwater Horizon oil spill. In addition, it has participated in elections with the aim of opposing the American occupation of Iraq and building a mass socialist party with an international perspective. Despite having been active for over a decade, the Socialist Equality Party held its founding congress in 2008, where it adopted a statement of principles and a historical document. White has Ballot Access in: CO, LA, WI Learn more about Jerry White and Socialist Equality Party on Wikipedia

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• Weird CSS-behaviour [migrated]

  - by WMRKameleon

  <!DOCTYPE html> <html> <head> <title>PakHet</title> <link rel="stylesheet" type="text/css" href="css/basis.css" /> </head> <body> <div class="wrapper"> <div id='cssmenu'> <ul> <li class="active"><a href='index.html'><span>Start</span></a></li> <li><a href='pakhet.html'><span>Over PakHet</span></a></li> <li><a href='overons.html'><span>Over Ons</span></a></li> <li class='has-sub '><a href='#'><span>Uw pakket</span></a> <ul> <li><a href='aanmelden.php'><span>Aanmelden</span></a></li> <li><a href='traceren.php'><span>Traceren</span></a></li> </ul> </li> </ul> </div> <div class="header"> <h1>Hier komt de titel van de website</h1> </div> <div class="content"> <p>Dit is de tekst van de content. Dit is de indexpagina.</p> </div> </div> </body> </html> And this is the CSS: /* CSS RESET */ html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video, *{ margin: 0; padding: 0; border: 0; vertical-align: baseline; } table { border-collapse: collapse; border-spacing: 0; } /* Einde CSS RESET, nu echte code */ html, body{ background:url(../images/bg_picture.jpg) fixed no-repeat; } .wrapper{ margin:0 auto; } .header{ margin:0 auto; background-color:rgba(0, 0, 0, 0.4); } .content{ background-color:rgba(0, 0, 0, 0.4); width:600px; margin:0 auto; margin-top:50px; } .content p{ color:white; text-shadow:1px 1px 0 rgba(0,0,0, 0.5); font-family:"Lucida Grande", sans-serif; } #cssmenu{ height:37px; display:block; padding:0; margin: 0; border:1px solid; } #cssmenu > ul {list-style:inside none; padding:0; margin:0;} #cssmenu > ul > li {list-style:inside none; padding:0; margin:0; float:left; display:block; position:relative;} #cssmenu > ul > li > a{ outline:none; display:block; position:relative; padding:12px 20px; font:bold 13px/100% "Lucida Grande", Helvetica, sans-serif; text-align:center; text-decoration:none; text-shadow:1px 1px 0 rgba(0,0,0, 0.4); } #cssmenu > ul > li:first-child > a{border-radius:5px 0 0 5px;} #cssmenu > ul > li > a:after{ content:''; position:absolute; border-right:1px solid; top:-1px; bottom:-1px; right:-2px; z-index:99; } #cssmenu ul li.has-sub:hover > a:after{top:0; bottom:0;} #cssmenu > ul > li.has-sub > a:before{ content:''; position:absolute; top:18px; right:6px; border:5px solid transparent; border-top:5px solid #fff; } #cssmenu > ul > li.has-sub:hover > a:before{top:19px;} #cssmenu ul li.has-sub:hover > a{ background:#3f3f3f; border-color:#3f3f3f; padding-bottom:13px; padding-top:13px; top:-1px; z-index:999; } #cssmenu ul li.has-sub:hover > ul, #cssmenu ul li.has-sub:hover > div{display:block;} #cssmenu ul li.has-sub > a:hover{background:#3f3f3f; border-color:#3f3f3f;} #cssmenu ul li > ul, #cssmenu ul li > div{ display:none; width:auto; position:absolute; top:38px; padding:10px 0; background:#3f3f3f; border-radius:0 0 5px 5px; z-index:999; } #cssmenu ul li > ul{width:200px;} #cssmenu ul li > ul li{display:block; list-style:inside none; padding:0; margin:0; position:relative;} #cssmenu ul li > ul li a{ outline:none; display:block; position:relative; margin:0; padding:8px 20px; font:10pt "Lucida Grande", Helvetica, sans-serif; color:#fff; text-decoration:none; text-shadow:1px 1px 0 rgba(0,0,0, 0.5); } #cssmenu, #cssmenu > ul > li > ul > li a:hover{ background:#333333; background:-moz-linear-gradient(top, #333333 0%, #222222 100%); background:-webkit-gradient(linear, left top, left bottom, color-stop(0%,#333333), color-stop(100%,#222222)); background:-webkit-linear-gradient(top, #333333 0%,#222222 100%); background:-o-linear-gradient(top, #333333 0%,#222222 100%); background:-ms-linear-gradient(top, #333333 0%,#222222 100%); background:linear-gradient(top, #333333 0%,#222222 100%); filter:progid:DXImageTransform.Microsoft.gradient( startColorstr='#333333', endColorstr='#222222',GradientType=0 ); } #cssmenu{border-color:#000;} #cssmenu > ul > li > a{border-right:1px solid #000; color:#fff;} #cssmenu > ul > li > a:after{border-color:#444;} #cssmenu > ul > li > a:hover{background:#111;} #cssmenu > ul > li.active > a{ color:orange; } .header{ clear:both; } The problem is that, whenever I hover on the dropdown-menu, that a 1px margin appears in between the menu and the header. Can I solve that? I can't seem to find the solution.

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• Minecraft-style player-gound collision detection

  - by khyperia

  The title pretty much says it all... (Minecraft is a game consisting of evenly-spaced cubes for terrain, like voxels) Note: I am using C# XNA. I am pretty sure AABB is the way to go, yet I don't know how to implement it. I admit, I'm almost looking for code, but theories/ideas are very welcome. Important capabilities of my code: I have a function that can get a block anywhere in the world, and get a BoundingBox for that cube. Hence, I have created a BoundingBox for the player to collide with those cubes. My idea was to get the blocks around the player (maybe 4x6x4) and test against those. The problems I have been having: Say the world is a flat plane. If I use the method of go the shortest distance out, then if the player is slightly clipped into the ground (from gravity), but even slighter into the next block over, then the player will be pushed sideways (and so cannot walk along ground). Of course, this is assuming I react to every block intersected. Another problem is knowing which direction to go (aka negative x or positive). That takes me to my final problem- Getting the amount of intersection, in the correct direction (+ or -) has been tough for me. I hope I haven't been too hard to understand, I'm not too good at explaining things... And if this question has already been asked, I'm sorry, I looked for it... for 3 days straight. One last thing, if someone knows exactly how minecraft does it, or has source (I know MC modders have the source, how else would they mod), please point me to it.

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