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• Up in the Air: Team Oracle Play-by-Play

  - by Aaron Lazenby

  Yesterday, I had the amazing opportunity to fly along with Sean D. Tucker and Team Oracle. Leaving from the San Carols airport, we did a 30 minute flight over the Pacific just south of the coastal town of Half Moon Bay. In that half hour, I rode through a massive 4G loop, survived a crushing hammerhead, and took control of the plane to perform a basic wing over (you can learn what the heck I'm talking about by visiting this website). I have lots of great video, but it's going to take me some time to make sense of it. For now, here's my Twitter-based play-by-play of yesterday's events. Many thanks to Sean D. Tucker and the whole crew (Ben and Ian, especially) for this great opportunity to fly with Team Oracle.Live tweets from @OracleProfitI will be spending the afternoon in a stunt plane, upside down above the San Francisco bay. http://bit.ly/cwkrkIAt the San Carlos airport. More than slightly freaked out. Shaking hands diminish texting ability. Slightly reassuring. http://yfrog.com/1qt61nj There go the doors to the photo plane... #teamoracle http://yfrog.com/58ywljSean D Tucker assures me: "The sky is a great place to be." Helpful, but I'm still nervous. #teamoracle"You get a parachute. He gets a harness." How was this decision made? #teamoracleThe plane with @radu43 has returned. I'm up next...Couldn't help myself...drank a soda before flying. Mistake? We'll see... #teamoracleAdvice of the day "If you pull with two hands, you improve the chances of the chute deploying on the first try." Lovely. #teamoracleI feel so strange. But I flew a high performance airplane. And did an aerobatics move. Wild. #teamoracle"Flying ten feet off he ground, upside-down at 250 miles per hour isn't exciting to me." Sean D. Tucker #teamoracle"What is exciting to me is flying that perfect pattern, just like I imagined it in my head." Sean D. Tucker #teamoracle"You're going to sleep well tonight. You just carried four times your body weight." #teamoracle #gforce Just watched the #teamoracle plane take off for its flight home. I'm waiting for Caltrain. #undignifiedanticlimaxEnough with the #teamoracle. Check http://blogs.oracle.com/profit for the video. Coming soon! 

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• SQL SERVER – A Quick Look at Logging and Ideas around Logging

  - by pinaldave

  This blog post is written in response to the T-SQL Tuesday post on Logging. When someone talks about logging, personally I get lots of ideas about it. I have seen logging as a very generic term. Let me ask you this question first before I continue writing about logging. What is the first thing comes to your mind when you hear word “Logging”? Now ask the same question to the guy standing next to you. I am pretty confident that you will get  a different answer from different people. I decided to do this activity and asked 5 SQL Server person the same question. Question: What is the first thing comes to your mind when you hear the word “Logging”? Strange enough I got a different answer every single time. Let me just list what answer I got from my friends. Let us go over them one by one. Output Clause The very first person replied output clause. Pretty interesting answer to start with. I see what exactly he was thinking. SQL Server 2005 has introduced a new OUTPUT clause. OUTPUT clause has access to inserted and deleted tables (virtual tables) just like triggers. OUTPUT clause can be used to return values to client clause. OUTPUT clause can be used with INSERT, UPDATE, or DELETE to identify the actual rows affected by these statements. Here are some references for Output Clause: OUTPUT Clause Example and Explanation with INSERT, UPDATE, DELETE Reasons for Using Output Clause – Quiz Tips from the SQL Joes 2 Pros Development Series – Output Clause in Simple Examples Error Logs I was expecting someone to mention Error logs when it is about logging. The error log is the most looked place when there is any error either with the application or there is an error with the operating system. I have kept the policy to check my server’s error log every day. The reason is simple – enough time in my career I have figured out that when I am looking at error logs I find something which I was not expecting. There are cases, when I noticed errors in the error log and I fixed them before end user notices it. Other common practices I always tell my DBA friends to do is that when any error happens they should find relevant entries in the error logs and document the same. It is quite possible that they will see the same error in the error log  and able to fix the error based on the knowledge base which they have created. There can be many different kinds of error log files exists in SQL Server as well – 1) SQL Server Error Logs 2) Windows Event Log 3) SQL Server Agent Log 4) SQL Server Profile Log 5) SQL Server Setup Log etc. Here are some references for Error Logs: Recycle Error Log – Create New Log file without Server Restart SQL Error Messages Change Data Capture I got surprised with this answer. I think more than the answer I was surprised by the person who had answered me this one. I always thought he was expert in HTML, JavaScript but I guess, one should never assume about others. Indeed one of the cool logging feature is Change Data Capture. Change Data Capture records INSERTs, UPDATEs, and DELETEs applied to SQL Server tables, and makes a record available of what changed, where, and when, in simple relational ‘change tables’ rather than in an esoteric chopped salad of XML. These change tables contain columns that reflect the column structure of the source table you have chosen to track, along with the metadata needed to understand the changes that have been made. Here are some references for Change Data Capture: Introduction to Change Data Capture (CDC) in SQL Server 2008 Tuning the Performance of Change Data Capture in SQL Server 2008 Download Script of Change Data Capture (CDC) CDC and TRUNCATE – Cannot truncate table because it is published for replication or enabled for Change Data Capture Dynamic Management View (DMV) I like this answer. If asked I would have not come up with DMV right away but in the spirit of the original question, I think DMV does log the data. DMV logs or stores or records the various data and activity on the SQL Server. Dynamic management views return server state information that can be used to monitor the health of a server instance, diagnose problems, and tune performance. One can get plethero of information from DMVs – High Availability Status, Query Executions Details, SQL Server Resources Status etc. Here are some references for Dynamic Management View (DMV): SQL SERVER – Denali – DMV Enhancement – sys.dm_exec_query_stats – New Columns DMV – sys.dm_os_windows_info – Information about Operating System DMV – sys.dm_os_wait_stats Explanation – Wait Type – Day 3 of 28 DMV sys.dm_exec_describe_first_result_set_for_object – Describes the First Result Metadata for the Module Transaction Log Impact Detection Using DMV – dm_tran_database_transactions Log Files I almost flipped with this final answer from my friend. This should be probably the first answer. Yes, indeed log file logs the SQL Server activities. One can write infinite things about log file. SQL Server uses log file with the extension .ldf to manage transactions and maintain database integrity. Log file ensures that valid data is written out to database and system is in a consistent state. Log files are extremely useful in case of the database failures as with the help of full backup file database can be brought in the desired state (point in time recovery is also possible). SQL Server database has three recovery models – 1) Simple, 2) Full and 3) Bulk Logged. Each of the model uses the .ldf file for performing various activities. It is very important to take the backup of the log files (along with full backup) as one never knows when backup of the log file come into the action and save the day! How to Stop Growing Log File Too Big Reduce the Virtual Log Files (VLFs) from LDF file Log File Growing for Model Database – model Database Log File Grew Too Big master Database Log File Grew Too Big SHRINKFILE and TRUNCATE Log File in SQL Server 2008 Can I just say I loved this month’s T-SQL Tuesday Question. It really provoked very interesting conversation around me. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Optimization, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Java Spotlight Episode 138: Paul Perrone on Life Saving Embedded Java

  - by Roger Brinkley

  Interview with Paul Perrone, founder and CEO of Perrone Robotics, on using Java Embedded to test autonomous vehicle operations for the Insurance Institute for Highway Safety that will save lives. Right-click or Control-click to download this MP3 file. You can also subscribe to the Java Spotlight Podcast Feed to get the latest podcast automatically. If you use iTunes you can open iTunes and subscribe with this link: Java Spotlight Podcast in iTunes. Show Notes News JDK 8 is Feature Complete Java SE 7 Update 25 Released What should the JCP be doing? 2013 Duke's Choice Award Nominations Another Quick update to Code Signing Article on OTN Events June 24, Austin JUG, Austin, TX June 25, Virtual Developer Day - Java, EMEA, 10AM CEST Jul 16-19, Uberconf, Denver, USA Jul 22-24, JavaOne Shanghai, China Jul 29-31, JVM Summit Language, Santa Clara Sep 11-12, JavaZone, Oslo, Norway Sep 19-20, Strange Loop, St. Louis Sep 22-26 JavaOne San Francisco 2013, USA Feature Interview Paul J. Perrone is founder/CEO of Perrone Robotics. Paul architected the Java-based general-purpose robotics and automation software platform known as “MAX”. Paul has overseen MAX’s application to rapidly field self-driving robotic cars, unmanned air vehicles, factory and road-side automation applications, and a wide range of advanced robots and automaton applications. He fielded a self-driving autonomous robotic dune buggy in the historic 2005 Grand Challenge race across the Mojave desert and a self-driving autonomous car in the 2007 Urban Challenge through a city landscape. His work has been featured in numerous televised and print media including the Discovery Channel, a theatrical documentary, scientific journals, trade magazines, and international press. Since 2008, Paul has also been working as the chief software engineer, CTO, and roboticist automating rock star Neil Young’s LincVolt, a 1959 Lincoln Continental retro-fitted as a fully autonomous extended range electric vehicle. Paul has been an engineer, author of books and articles on Java, frequent speaker on Java, and entrepreneur in the robotics and software space for over 20 years. He is a member of the Java Champions program, recipient of three Duke Awards including a Gold Duke and Lifetime Achievement Award, has showcased Java-based robots at five JavaOne keynotes, and is a frequent JavaOne speaker and show floor participant. He holds a B.S.E.E. from Rutgers University and an M.S.E.E. from the University of Virginia. What’s Cool Shenandoah: A pauseless GC for OpenJDK

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• Gravity stops when side-collision detected

  - by Adrian Marszalek

  Please, look at this GIF: The label on the animation says "Move button is pressed, then released". And you can see when it's pressed (and player's getCenterY() is above wall getCenterY()), gravity doesn't work. I'm trying to fix it since yesterday, but I can't. All methods are called from game loop. public void move() { if (left) { switch (game.currentLevel()) { case 1: for (int i = 0; i < game.lvl1.getX().length; i++) game.lvl1.getX()[i] += game.physic.xVel; break; } } else if (right) { switch (game.currentLevel()) { case 1: for (int i = 0; i < game.lvl1.getX().length; i++) game.lvl1.getX()[i] -= game.physic.xVel; break; } } } int manCenterX, manCenterY, boxCenterX, boxCenterY; //gravity stop public void checkCollision() { for (int i = 0; i < game.lvl1.getX().length; i++) { manCenterX = (int) game.man.getBounds().getCenterX(); manCenterY = (int) game.man.getBounds().getCenterY(); if (game.man.getBounds().intersects(game.lvl1.getBounds(i))) { boxCenterX = (int) game.lvl1.getBounds(i).getCenterX(); boxCenterY = (int) game.lvl1.getBounds(i).getCenterY(); if (manCenterY - boxCenterY > 0 || manCenterY - boxCenterY < 0) { game.man.setyPos(-2f); game.man.isFalling = false; } } } } //left side of walls public void colliLeft() { for (int i = 0; i < game.lvl1.getX().length; i++) { if (game.man.getBounds().intersects(game.lvl1.getBounds(i))) { if (manCenterX - boxCenterX < 0) { for (int i1 = 0; i1 < game.lvl1.getX().length; i1++) { game.lvl1.getX()[i1] += game.physic.xVel; game.man.isFalling = true; } } } } } //right side of walls public void colliRight() { for (int i = 0; i < game.lvl1.getX().length; i++) { if (game.man.getBounds().intersects(game.lvl1.getBounds(i))) { if (manCenterX - boxCenterX > 0) { for (int i1 = 0; i1 < game.lvl1.getX().length; i1++) { game.lvl1.getX()[i1] += -game.physic.xVel; game.man.isFalling = true; } } } } } public void gravity() { game.man.setyPos(yVel); } //not called from gameloop: public void setyPos(float yPos) { this.yPos += yPos; }

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• C#: Optional Parameters - Pros and Pitfalls

  - by James Michael Hare

  When Microsoft rolled out Visual Studio 2010 with C# 4, I was very excited to learn how I could apply all the new features and enhancements to help make me and my team more productive developers. Default parameters have been around forever in C++, and were intentionally omitted in Java in favor of using overloading to satisfy that need as it was though that having too many default parameters could introduce code safety issues.  To some extent I can understand that move, as I’ve been bitten by default parameter pitfalls before, but at the same time I feel like Java threw out the baby with the bathwater in that move and I’m glad to see C# now has them. This post briefly discusses the pros and pitfalls of using default parameters.  I’m avoiding saying cons, because I really don’t believe using default parameters is a negative thing, I just think there are things you must watch for and guard against to avoid abuses that can cause code safety issues. Pro: Default Parameters Can Simplify Code Let’s start out with positives.  Consider how much cleaner it is to reduce all the overloads in methods or constructors that simply exist to give the semblance of optional parameters.  For example, we could have a Message class defined which allows for all possible initializations of a Message: 1: public class Message 2: { 3: // can either cascade these like this or duplicate the defaults (which can introduce risk) 4: public Message() 5: : this(string.Empty) 6: { 7: } 8:  9: public Message(string text) 10: : this(text, null) 11: { 12: } 13:  14: public Message(string text, IDictionary<string, string> properties) 15: : this(text, properties, -1) 16: { 17: } 18:  19: public Message(string text, IDictionary<string, string> properties, long timeToLive) 20: { 21: // ... 22: } 23: }   Now consider the same code with default parameters: 1: public class Message 2: { 3: // can either cascade these like this or duplicate the defaults (which can introduce risk) 4: public Message(string text = "", IDictionary<string, string> properties = null, long timeToLive = -1) 5: { 6: // ... 7: } 8: }   Much more clean and concise and no repetitive coding!  In addition, in the past if you wanted to be able to cleanly supply timeToLive and accept the default on text and properties above, you would need to either create another overload, or pass in the defaults explicitly.  With named parameters, though, we can do this easily: 1: var msg = new Message(timeToLive: 100);   Pro: Named Parameters can Improve Readability I must say one of my favorite things with the default parameters addition in C# is the named parameters.  It lets code be a lot easier to understand visually with no comments.  Think how many times you’ve run across a TimeSpan declaration with 4 arguments and wondered if they were passing in days/hours/minutes/seconds or hours/minutes/seconds/milliseconds.  A novice running through your code may wonder what it is.  Named arguments can help resolve the visual ambiguity: 1: // is this days/hours/minutes/seconds (no) or hours/minutes/seconds/milliseconds (yes) 2: var ts = new TimeSpan(1, 2, 3, 4); 3:  4: // this however is visually very explicit 5: var ts = new TimeSpan(days: 1, hours: 2, minutes: 3, seconds: 4);   Or think of the times you’ve run across something passing a Boolean literal and wondered what it was: 1: // what is false here? 2: var sub = CreateSubscriber(hostname, port, false); 3:  4: // aha! Much more visibly clear 5: var sub = CreateSubscriber(hostname, port, isBuffered: false);   Pitfall: Don't Insert new Default Parameters In Between Existing Defaults Now let’s consider a two potential pitfalls.  The first is really an abuse.  It’s not really a fault of the default parameters themselves, but a fault in the use of them.  Let’s consider that Message constructor again with defaults.  Let’s say you want to add a messagePriority to the message and you think this is more important than a timeToLive value, so you decide to put messagePriority before it in the default, this gives you: 1: public class Message 2: { 3: public Message(string text = "", IDictionary<string, string> properties = null, int priority = 5, long timeToLive = -1) 4: { 5: // ... 6: } 7: }   Oh boy have we set ourselves up for failure!  Why?  Think of all the code out there that could already be using the library that already specified the timeToLive, such as this possible call: 1: var msg = new Message(“An error occurred”, myProperties, 1000);   Before this specified a message with a TTL of 1000, now it specifies a message with a priority of 1000 and a time to live of -1 (infinite).  All of this with NO compiler errors or warnings. So the rule to take away is if you are adding new default parameters to a method that’s currently in use, make sure you add them to the end of the list or create a brand new method or overload. Pitfall: Beware of Default Parameters in Inheritance and Interface Implementation Now, the second potential pitfalls has to do with inheritance and interface implementation.  I’ll illustrate with a puzzle: 1: public interface ITag 2: { 3: void WriteTag(string tagName = "ITag"); 4: } 5:  6: public class BaseTag : ITag 7: { 8: public virtual void WriteTag(string tagName = "BaseTag") { Console.WriteLine(tagName); } 9: } 10:  11: public class SubTag : BaseTag 12: { 13: public override void WriteTag(string tagName = "SubTag") { Console.WriteLine(tagName); } 14: } 15:  16: public static class Program 17: { 18: public static void Main() 19: { 20: SubTag subTag = new SubTag(); 21: BaseTag subByBaseTag = subTag; 22: ITag subByInterfaceTag = subTag; 23:  24: // what happens here? 25: subTag.WriteTag(); 26: subByBaseTag.WriteTag(); 27: subByInterfaceTag.WriteTag(); 28: } 29: }   What happens?  Well, even though the object in each case is SubTag whose tag is “SubTag”, you will get: 1: SubTag 2: BaseTag 3: ITag   Why?  Because default parameter are resolved at compile time, not runtime!  This means that the default does not belong to the object being called, but by the reference type it’s being called through.  Since the SubTag instance is being called through an ITag reference, it will use the default specified in ITag. So the moral of the story here is to be very careful how you specify defaults in interfaces or inheritance hierarchies.  I would suggest avoiding repeating them, and instead concentrating on the layer of classes or interfaces you must likely expect your caller to be calling from. For example, if you have a messaging factory that returns an IMessage which can be either an MsmqMessage or JmsMessage, it only makes since to put the defaults at the IMessage level since chances are your user will be using the interface only. So let’s sum up.  In general, I really love default and named parameters in C# 4.0.  I think they’re a great tool to help make your code easier to read and maintain when used correctly. On the plus side, default parameters: Reduce redundant overloading for the sake of providing optional calling structures. Improve readability by being able to name an ambiguous argument. But remember to make sure you: Do not insert new default parameters in the middle of an existing set of default parameters, this may cause unpredictable behavior that may not necessarily throw a syntax error – add to end of list or create new method. Be extremely careful how you use default parameters in inheritance hierarchies and interfaces – choose the most appropriate level to add the defaults based on expected usage. Technorati Tags: C#,.NET,Software,Default Parameters

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• Plan Operator Tuesday round-up

  - by Rob Farley

  Eighteen posts for T-SQL Tuesday #43 this month, discussing Plan Operators. I put them together and made the following clickable plan. It’s 1000px wide, so I hope you have a monitor wide enough. Let me explain this plan for you (people’s names are the links to the articles on their blogs – the same links as in the plan above). It was clearly a SELECT statement. Wayne Sheffield (@dbawayne) wrote about that, so we start with a SELECT physical operator, leveraging the logical operator Wayne Sheffield. The SELECT operator calls the Paul White operator, discussed by Jason Brimhall (@sqlrnnr) in his post. The Paul White operator is quite remarkable, and can consume three streams of data. Let’s look at those streams. The first pulls data from a Table Scan – Boris Hristov (@borishristov)’s post – using parallel threads (Bradley Ball – @sqlballs) that pull the data eagerly through a Table Spool (Oliver Asmus – @oliverasmus). A scalar operation is also performed on it, thanks to Jeffrey Verheul (@devjef)’s Compute Scalar operator. The second stream of data applies Evil (I figured that must mean a procedural TVF, but could’ve been anything), courtesy of Jason Strate (@stratesql). It performs this Evil on the merging of parallel streams (Steve Jones – @way0utwest), which suck data out of a Switch (Paul White – @sql_kiwi). This Switch operator is consuming data from up to four lookups, thanks to Kalen Delaney (@sqlqueen), Rick Krueger (@dataogre), Mickey Stuewe (@sqlmickey) and Kathi Kellenberger (@auntkathi). Unfortunately Kathi’s name is a bit long and has been truncated, just like in real plans. The last stream performs a join of two others via a Nested Loop (Matan Yungman – @matanyungman). One pulls data from a Spool (my post – @rob_farley) populated from a Table Scan (Jon Morisi). The other applies a catchall operator (the catchall is because Tamera Clark (@tameraclark) didn’t specify any particular operator, and a catchall is what gets shown when SSMS doesn’t know what to show. Surprisingly, it’s showing the yellow one, which is about cursors. Hopefully that’s not what Tamera planned, but anyway...) to the output from an Index Seek operator (Sebastian Meine – @sqlity). Lastly, I think everyone put in 110% effort, so that’s what all the operators cost. That didn’t leave anything for me, unfortunately, but that’s okay. Also, because he decided to use the Paul White operator, Jason Brimhall gets 0%, and his 110% was given to Paul’s Switch operator post. I hope you’ve enjoyed this T-SQL Tuesday, and have learned something extra about Plan Operators. Keep your eye out for next month’s one by watching the Twitter Hashtag #tsql2sday, and why not contribute a post to the party? Big thanks to Adam Machanic as usual for starting all this. @rob_farley

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• Project Euler 18: (Iron)Python

  - by Ben Griswold

  In my attempt to learn (Iron)Python out in the open, here’s my solution for Project Euler Problem 18.  As always, any feedback is welcome. # Euler 18 # http://projecteuler.net/index.php?section=problems&id=18 # By starting at the top of the triangle below and moving # to adjacent numbers on the row below, the maximum total # from top to bottom is 23. # # 3 # 7 4 # 2 4 6 # 8 5 9 3 # # That is, 3 + 7 + 4 + 9 = 23. # Find the maximum total from top to bottom of the triangle below: # 75 # 95 64 # 17 47 82 # 18 35 87 10 # 20 04 82 47 65 # 19 01 23 75 03 34 # 88 02 77 73 07 63 67 # 99 65 04 28 06 16 70 92 # 41 41 26 56 83 40 80 70 33 # 41 48 72 33 47 32 37 16 94 29 # 53 71 44 65 25 43 91 52 97 51 14 # 70 11 33 28 77 73 17 78 39 68 17 57 # 91 71 52 38 17 14 91 43 58 50 27 29 48 # 63 66 04 68 89 53 67 30 73 16 69 87 40 31 # 04 62 98 27 23 09 70 98 73 93 38 53 60 04 23 # NOTE: As there are only 16384 routes, it is possible to solve # this problem by trying every route. However, Problem 67, is the # same challenge with a triangle containing one-hundred rows; it # cannot be solved by brute force, and requires a clever method! ;o) import time start = time.time() triangle = [ [75], [95, 64], [17, 47, 82], [18, 35, 87, 10], [20, 04, 82, 47, 65], [19, 01, 23, 75, 03, 34], [88, 02, 77, 73, 07, 63, 67], [99, 65, 04, 28, 06, 16, 70, 92], [41, 41, 26, 56, 83, 40, 80, 70, 33], [41, 48, 72, 33, 47, 32, 37, 16, 94, 29], [53, 71, 44, 65, 25, 43, 91, 52, 97, 51, 14], [70, 11, 33, 28, 77, 73, 17, 78, 39, 68, 17, 57], [91, 71, 52, 38, 17, 14, 91, 43, 58, 50, 27, 29, 48], [63, 66, 04, 68, 89, 53, 67, 30, 73, 16, 69, 87, 40, 31], [04, 62, 98, 27, 23, 9, 70, 98, 73, 93, 38, 53, 60, 04, 23]] # Loop through each row of the triangle starting at the base. for a in range(len(triangle) - 1, -1, -1): for b in range(0, a): # Get the maximum value for adjacent cells in current row. # Update the cell which would be one step prior in the path # with the new total. For example, compare the first two # elements in row 15. Add the max of 04 and 62 to the first # position of row 14.This provides the max total from row 14 # to 15 starting at the first position. Continue to work up # the triangle until the maximum total emerges at the # triangle's apex. triangle [a-1][b] += max(triangle [a][b], triangle [a][b+1]) print triangle [0][0] print "Elapsed Time:", (time.time() - start) * 1000, "millisecs" a=raw_input('Press return to continue')

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• How do I Integrate Production Database Hot Fixes into Shared Database Development model?

  - by TetonSig

  We are using SQL Source Control 3, SQL Compare, SQL Data Compare from RedGate, Mercurial repositories, TeamCity and a set of 4 environments including production. I am working on getting us to a dedicated environment per developer, but for at least the next 6 months we are stuck with a shared model. To summarize our current system, we have a DEV SQL server where developers first make changes/additions. They commit their changes through SQL Source Control to a local hgdev repository. When they execute an hg push to the main repository, TeamCity listens for that and then (among other things) pushes hgdev repository to hgrc. Another TeamCity process listens for that and does a pull from hgrc and deploys the latest to a QA SQL Server where regression and integration tests are run. When those are passed a push from hgrc to hgprod occurs. We do a compare of hgprod to our PREPROD SQL Server and generate deployment/rollback scripts for our production release. Separate from the above we have database Hot Fixes that will need to be applied in between releases. The process there is for our Operations team make changes on the PreProd database, and then after testing, to use SQL Source Control to commit their hot fix changes to hgprod from the PREPROD database, and then do a compare from hgprod to PRODUCTION, create deployment scripts and run them on PRODUCTION. If we were in a dedicated database per developer model, we could simply automatically push hgprod back to hgdev and merge in the hot fix change (through TeamCity monitoring for hgprod checkins) and then developers would pick it up and merge it to their local repository and database periodically. However, given that with a shared model the DEV database itself is the source of all changes, this won't work. Pushing hotfixes back to hgdev will show up in SQL Source Control as being different than DEV SQL Server and therefore we need to overwrite the reposistory with the "change" from the DEV SQL Server. My only workaround so far is to just have OPS assign a developer the hotfix ticket with a script attached and then we run their hotfixes against DEV ourselves to merge them back in. I'm not happy with that solution. Other than working faster to get to dedicated environment, are they other ways to keep this loop going automatically?

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• Scrum and Team Consolidation

  - by John K. Hines

  I’m still working my way through one of the more painful team consolidations of my career.  One thing that’s made it hard was my assumption that the use of Agile methods and Scrum would make everything easy.  Take three teams, make all work visible, track it, and presto: An efficient, functioning software development team. What I’ve come to realize is that the primary benefit of Scrum is that Scrum brings teams closer to their customers.  Frequent meetings, short iterations, and phased deployments are all meant to keep the customer in the loop.  It’s true that as teams become proficient with Scrum they tend to become more efficient.  But I don’t think it’s true that Scrum automatically helps people work together. Instead, Scrum can point out when teams aren’t good at working together.   And it really illustrates when teams, especially teams in sustaining mode, are reacting to their customers instead of innovating with them.  At the moment we’ve inherited a huge backlog of tools, processes, and personalities.  It’s up to us to sort them all out.  Unfortunately, after 7 &frac12; months we’re still sorting. What I’d recommend for any blended team is to look at your current product lifecycles and work on a single lifecycle for all work.  If you can’t objectively come up with one process, that’s a good indication that the new team might not be a good fit for being a single unit (which happens all the time in bigger companies).  Go ahead & self-organize into sub-teams.  Then repeat the process. If you can come up with a single process, tackle each piece and standardize all of them.  Do this as soon as possible, as it can be uncomfortable.  Standardize your requirements gathering and tracking, your exploration and technical analysis, your project planning, development standards, validation and sustaining processes.  Standardize all of it.  Make this your top priority, get it out of the way, and get back to work. Lastly, managers of blended teams should realize what I’m suggesting is a disruptive process.  But you’ve just reorganized the team is already disrupted.   Don’t pull the bandage off slowly and force the team through a prolonged transition phase, lowering their productivity over the long term.  You can role model leadership to your team and drive a true consolidation.  Destroy roadblocks, reassure those on your team who are afraid of change, and push forward to create something efficient and beautiful.  Then use Scrum to reengage your customers in a way that they’ll love. Technorati tags: Scrum Scrum Process

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• Craftsmanship Tour: Day 2 Obtiva

  - by Liam McLennan

  I like Chicago. It is a great city for travellers. From the moment I got off the plane at O’Hare everything was easy. I took the train to ‘the Loop’ and walked around the corner to my hotel, Hotel Blake on Dearborn St. Sadly, the elevated train lines in downtown Chicago remind me of ‘Shall We Dance’. Hotel Blake is excellent (except for the breakfast) and the concierge directed me to a pizza place called Lou Malnati's for Chicago style deep-dish pizza. Lou Malnati’s would be a great place to go with a group of friends. I felt strange dining there by myself, but the food and service were excellent. As usual in the United States the portion was so large that I could not finish it, but oh how I tried. Dave Hoover, who invited me to Obtiva for the day, had asked me to arrive at 9:45am. I was up early and had some time to kill so I stopped at the Willis Tower, since it was on my way to the office. Willis Tower is 1,451 feet (442 m) tall and has an observation deck at the top. Around the observation deck are a set of acrylic boxes, protruding from the side of the building. Brave soles can walk out on the perspex and look between their feet all the way down to the street. It is unnerving. Obtiva is a progressive, craftsmanship-focused software development company in downtown Chicago. Dave even wrote a book, Apprenticeship Patterns, that provides a catalogue of patterns to assist aspiring software craftsmen to achieve their goals. I spent the morning working in Obtiva’s software studio, an open xp-style office that houses Obtiva’s in-house development team. For lunch Dave Hoover, Corey Haines, Cory Foy and I went to a local Greek restaurant (not Dancing Zorbas). Dave, Corey and Cory are three smart and motivated guys and I found their ideas enlightening. It was especially great to chat with Corey Haines since he was the inspiration for my craftsmanship tour in the first place. After lunch I recorded a brief interview with Dave. Unfortunately, the battery in my camera went flat so I missed recording some interesting stuff. Interview with Dave Hoover In the evening Obtiva hosted an rspec hackfest with David Chelimsky and others. This was an excellent opportunity to be around some of the very best ruby programmers. At 10pm I went back to my hotel to get some rest before my train north the next morning.

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• How to pad number with leading zero with C#

  - by Jalpesh P. Vadgama

  Recently I was working with a project where I was in need to format a number in such a way which can apply leading zero for particular format.  So after doing such R and D I have found a great way to apply this leading zero format. I was having need that I need to pad number in 5 digit format. So following is a table in which format I need my leading zero format. 1-> 00001 20->00020 300->00300 4000->04000 50000->5000 So in the above example you can see that 1 will become 00001 and 20 will become 00200 format so on. So to display an integer value in decimal format I have applied interger.Tostring(String) method where I have passed “Dn” as the value of the format parameter, where n represents the minimum length of the string. So if we pass 5 it will have padding up to 5 digits. So let’s create a simple console application and see how its works. Following is a code for that. using System; namespace LeadingZero { class Program { static void Main(string[] args) { int a = 1; int b = 20; int c = 300; int d = 4000; int e = 50000; Console.WriteLine(string.Format("{0}------>{1}",a,a.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", b, b.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", c, c.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", d, d.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", e, e.ToString("D5"))); Console.ReadKey(); } } } As you can see in the above code I have use string.Format function to display value of integer and after using integer value’s  ToString method. Now Let’s run the console application and following is the output as expected. Here you can see the integer number are converted into the exact output that we requires. That’s it you can see it’s very easy. We have written code in nice clean way and without writing any extra code or loop. Hope you liked it. Stay tuned for more.. Till than happy programming.

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• How To Approach 360 Degree Snake

  - by Austin Brunkhorst

  I've recently gotten into XNA and must say I love it. As sort of a hello world game I decided to create the classic game "Snake". The 90 degree version was very simple and easy to implement. But as I try to make a version of it that allows 360 degree rotation using left and right arrows, I've come into sort of a problem. What i'm doing now stems from the 90 degree version: Iterating through each snake body part beginning at the tail, and ending right before the head. This works great when moving every 100 milliseconds. The problem with this is that it makes for a choppy style of gameplay as technically the game progresses at only 6 fps rather than it's potential 60. I would like to move the snake every game loop. But unfortunately because the snake moves at the rate of it's head's size it goes way too fast. This would mean that the head would need to move at a much smaller increment such as (2, 2) in it's direction rather than what I have now (32, 32). Because I've been working on this game off and on for a couple of weeks while managing school I think that I've been thinking too hard on how to accomplish this. It's probably a simple solution, i'm just not catching it. Here's some pseudo code for what I've tried based off of what makes sense to me. I can't really think of another way to do it. for(int i = SnakeLength - 1; i > 0; i--){ current = SnakePart[i], next = SnakePart[i - 1]; current.x = next.x - (current.width * cos(next.angle)); current.y = next.y - (current.height * sin(next.angle)); current.angle = next.angle; } SnakeHead.x += cos(SnakeAngle) * SnakeSpeed; SnakeHead.y += sin(SnakeAngle) * SnakeSpeed; This produces something like this: Code in Action. As you can see each part always stays behind the head and doesn't make a "Trail" effect. A perfect example of what i'm going for can be found here: Data Worm. Not the viewport rotation but the trailing effect of the triangles. Thanks for any help!

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• Keep website and webservices warm with zero coding

  - by oazabir

  If you want to keep your websites or webservices warm and save user from seeing the long warm up time after an application pool recycle, or IIS restart or new code deployment or even windows restart, you can use the tinyget command line tool, that comes with IIS Resource Kit, to hit the site and services and keep them warm. Here’s how: First get tinyget from here. Download and install the IIS 6.0 Resource Kit on some PC. Then copy the tinyget.exe from “c:\program files…\IIS 6.0 ResourceKit\Tools'\tinyget” to the server where your IIS 6.0 or IIS 7 is running. Then create a batch file that will hit the pages and webservices. Something like this: SET TINYGET=C:\Program Files (x86)\IIS Resources\TinyGet\tinyget.exe"%TINYGET%" -srv:dropthings.omaralzabir.com -uri:http://dropthings.omaralzabir.com/ -status:200"%TINYGET%" -srv:dropthings.omaralzabir.com -uri:http://dropthings.omaralzabir.com/WidgetService.asmx?WSDL - status:200 First I am hitting the homepage to keep the webpage warm. Then I am hitting the webservice URL with ?WSDL parameter, which allows ASP.NET to compile the service if not already compiled and walk through all the operations and reflect on them and thus loading all related DLLs into memory and reducing the warmup time when hit. Tinyget gets the servers name or IP in the –srv parameter and then the actual URI in the –uri. I have specified what’s the HTTP response code to expect in –status parameter. It ensures the site is alive and is returning http 200 code. Besides just warming up a site, you can do some load test on the site. Tinyget can run in multiple threads and run loops to hit some URL. You can literally blow up a site with commands like this: "%TINYGET%" -threads:30 -loop:100 -srv:google.com -uri:http://www.google.com/ -status:200 Tinyget is also pretty useful to run automated tests. You can record http posts in a text file and then use it to make http posts to some page. Then you can put matching clause to check for certain string in the output to ensure the correct response is given. Thus with some simple command line commands, you can warm up, do some transactions, validate the site is giving off correct response as well as run a load test to ensure the server performing well. Very cheap way to get a lot done.

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• How To show document directory save image in thumbnail in cocos2d class

  - by Anil gupta

  I have just implemented multiple photo selection from iphone photo library and i am saving all selected photo in document directory every time as a array, now i want to show all saved images in my class from document directory as a thumbnail, i have tried some logic but my game getting crashing, My code is below. Any help will be appreciate. Thanks in advance. -(id) init { // always call "super" init // Apple recommends to re-assign "self" with the "super" return value if( (self=[super init])) { CCSprite *photoalbumbg = [CCSprite spriteWithFile:@"photoalbumbg.png"]; photoalbumbg.anchorPoint = ccp(0,0); [self addChild:photoalbumbg z:0]; //Background Sound // [[SimpleAudioEngine sharedEngine]playBackgroundMusic:@"Background Music.wav" loop:YES]; CCSprite *photoalbumframe = [CCSprite spriteWithFile:@"photoalbumframe.png"]; photoalbumframe.position = ccp(160,240); [self addChild:photoalbumframe z:2]; CCSprite *frame = [CCSprite spriteWithFile:@"Photo-Frames.png"]; frame.position = ccp(160,270); [self addChild:frame z:1]; /*_____________________________________________________________________________________*/ CCMenuItemImage * upgradebtn = [CCMenuItemImage itemFromNormalImage:@"AlbumUpgrade.png" selectedImage:@"AlbumUpgrade.png" target:self selector:@selector(Upgrade:)]; CCMenu * fMenu = [CCMenu menuWithItems:upgradebtn,nil]; fMenu.position = ccp(200,110); [self addChild:fMenu z:3]; NSError *error; NSFileManager *fM = [NSFileManager defaultManager]; NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]; NSLog(@"Documents directory: %@", [fM contentsOfDirectoryAtPath:documentsDirectory error:&error]); NSArray *allfiles = [fM contentsOfDirectoryAtPath :documentsDirectory error:&error]; directoryList = [[NSMutableArray alloc] init]; for(NSString *file in allfiles) { NSString *path = [documentsDirectory stringByAppendingPathComponent:file]; [directoryList addObject:file]; } NSLog(@"array file name value ==== %@", directoryList); CCSprite *temp = [CCSprite spriteWithFile:[directoryList objectAtIndex:0]]; [temp setTextureRect:CGRectMake(160.0f, 240.0f, 50,50)]; // temp.anchorPoint = ccp(0,0); [self addChild:temp z:10]; for(UIImage *file in directoryList) { // NSData *pngData = [NSData dataWithContentsOfFile:file]; // image = [UIImage imageWithData:pngData]; NSLog(@"uiimage = %@",image); // UIImage *image = [UIImage imageWithContentsOfFile:file]; for (int i=1; i<=3; i++) { for (int j=1;j<=3; j++) { CCTexture2D *tex = [[[CCTexture2D alloc] initWithImage:file] autorelease]; CCSprite *selectedimage = [CCSprite spriteWithTexture:tex rect:CGRectMake(0, 0, 67, 66)]; selectedimage.position = ccp(100*i,350*j); [self addChild:selectedimage]; } } } } return self; }

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• Performance problems loading XML with SSIS, an alternative way!

  - by AtulThakor

  I recently needed to load several thousand XML files into a SQL database, I created an SSIS package which was created as followed: Using a foreach container to loop through a directory and load each file path into a variable, the “Import XML” dataflow would then load each XML file into a SQL table.       Running this, it took approximately 1 second to load each file which seemed a massive amount of time to parse the XML and load the data, speaking to my colleague Martin Croft, he suggested the use of T-SQL Bulk Insert and OpenRowset, so we adjusted the package as followed:     The same foreach container was used but instead the following SQL command was executed (this is an expression):     "INSERT INTO MyTable(FileDate) SELECT   CAST(bulkcolumn AS XML)     FROM OPENROWSET(         BULK         '" + @[User::CurrentFile]  + "',         SINGLE_BLOB ) AS x"     Using this method we managed to load approximately 20 records per second, much faster…for data loading! For what we wanted to achieve this was perfect but I’ll leave you with the following points when making your own decision on which solution you decide to choose!      Openrowset Method Much faster to get the data into SQL You’ll need to parse or create a view over the XML data to allow the data to be more usable(another post on this!) Not able to apply validation/transformation against the data when loading it The SQL Server service account will need permission to the file No schema validation when loading files SSIS Slower (in our case) Schema validation Allows you to apply transformations/joins to the data Permissions should be less of a problem Data can be loaded into the final form through the package When using a schema validation errors can fail the package (I’ll do another post on this)

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• how does openvpn decide which interface to get IP addrs from

  - by bkrupa

  Using ubuntu 10.04 on both ends. We have a client and server machine on the SAME network attempting to make a vpn connection. We use the config files from here and made minimal changes. The server and client start and seem to connect without any trouble. The server looks like: Wed Feb 23 22:13:22 2011 MULTI: multi_create_instance called Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Re-using SSL/TLS context Wed Feb 23 22:13:22 2011 192.168.1.55:47166 LZO compression initialized Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Control Channel MTU parms [ L:1574 D:138 EF:38 EB:0 ET:0 EL:0 ] Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Data Channel MTU parms [ L:1574 D:1450 EF:42 EB:135 ET:32 EL:0 AF:3/1 ] Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Local Options hash (VER=V4): 'f7df56b8' Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Expected Remote Options hash (VER=V4): 'd79ca330' Wed Feb 23 22:13:22 2011 192.168.1.55:47166 TLS: Initial packet from 192.168.1.55:47166, sid=69112e42 5458135b *...* Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA Wed Feb 23 22:13:22 2011 192.168.1.55:47166 [client1] Peer Connection Initiated with 192.168.1.55:47166 On the client side the connection looks like: Wed Feb 23 22:20:07 2011 [server] Peer Connection Initiated with [AF_INET]192.168.1.41:1194 Wed Feb 23 22:20:10 2011 SENT CONTROL [server]: 'PUSH_REQUEST' (status=1) Wed Feb 23 22:20:10 2011 PUSH: Received control message: 'PUSH_REPLY,route-gateway 10.8.0.4,ping 10,ping-restart 120,ifconfig 10.8.0.50 255.255.255.0' ... Wed Feb 23 22:20:10 2011 /sbin/ifconfig tap0 10.8.0.50 netmask 255.255.255.0 mtu 1500 broadcast 10.8.0.255 Wed Feb 23 22:20:10 2011 Initialization Sequence Completed The openvpn server has been configured to assign ip addresses in the range 10.8.0.* and the client has been given 10.8.0.50. When I run the following nmap from the client: Starting Nmap 5.00 ( http://nmap.org ) at 2011-02-23 22:04 EST Host 10.8.0.50 is up (0.00047s latency). Nmap done: 256 IP addresses (1 host up) scanned in 30.34 seconds Host 192.168.1.1 is up (0.0025s latency). Host 192.168.1.18 is up (0.074s latency). Host 192.168.1.41 is up (0.0024s latency). Host 192.168.1.55 is up (0.00018s latency). Nmap done: 256 IP addresses (4 hosts up) scanned in 6.33 seconds If I run an nmap from the server on 10.8.0.* I get nothing. If the client has two interfaces (wireless and tap device) when you look for a certain ip address, how does it decide which interface to connect on? edit I am trying to set up a vpn so that I can connect to my home network from a remote network. It seems like openvpn is connecting but none of the computers on my home network appear as network machines even after the connection is "Established". Stripped versions of the client and server config files are posted below. Thanks for any help you can offer. server.conf port 1194 proto udp dev tap ca /etc/openvpn/easy-rsa/keys/ca.crt cert /etc/openvpn/easy-rsa/keys/server.crt key /etc/openvpn/easy-rsa/keys/server.key # This file should be kept secret dh /etc/openvpn/easy-rsa/keys/dh1024.pem ifconfig-pool-persist ipp.txt server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100 keepalive 10 120 comp-lzo persist-key persist-tun status openvpn-status.log verb 3 client.conf client dev tap dev-node tap0901 proto udp remote ********** 1194 resolv-retry infinite nobind persist-key persist-tun ca ca.crt cert client1.crt key client1.key comp-lzo verb 3 one other thing that might be helpful, I tried to connect using the openvpn gui for windows and the connection stalls out on "obtaining configuration" and the bar just scrolls forever.

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• Implement Negascout Algorithm with stack

  - by Dan

  I'm not familiar with how these stack exchange accounts work so if this is double posting I apologize. I asked the same thing on stackoverflow. I have added an AI routine to a game I am working on using the Negascout algorithm. It works great, but when I set a higher maximum depth it can take a few seconds to complete. The problem is it blocks the main thread, and the framework I am using does not have a way to deal with multi-threading properly across platforms. So I am trying to change this routine from recursively calling itself, to just managing a stack (vector) so that I can progress through the routine at a controlled pace and not lock up the application while the AI is thinking. I am getting hung up on the second recursive call in the loop. It relies on a returned value from the first call, so I don't know how to add these to a stack. My Working c++ Recursive Code: MoveScore abNegascout(vector<vector<char> > &board, int ply, int alpha, int beta, char piece) { if (ply==mMaxPly) { return MoveScore(evaluation.evaluateBoard(board, piece, oppPiece)); } int currentScore; int bestScore = -INFINITY; MoveCoord bestMove; int adaptiveBeta = beta; vector<MoveCoord> moveList = evaluation.genPriorityMoves(board, piece, findValidMove(board, piece, false)); if (moveList.empty()) { return MoveScore(bestScore); } bestMove = moveList[0]; for(int i=0;i<moveList.size();i++) { MoveCoord move = moveList[i]; vector<vector<char> > newBoard; newBoard.insert( newBoard.end(), board.begin(), board.end() ); effectMove(newBoard, piece, move.getRow(), move.getCol()); // First Call ****** MoveScore current = abNegascout(newBoard, ply+1, -adaptiveBeta, -max(alpha,bestScore), oppPiece); currentScore = - current.getScore(); if (currentScore>bestScore){ if (adaptiveBeta == beta || ply>=(mMaxPly-2)){ bestScore = currentScore; bestMove = move; }else { // Second Call ****** current = abNegascout(newBoard, ply+1, -beta, -currentScore, oppPiece); bestScore = - current.getScore(); bestMove = move; } if(bestScore>=beta){ return MoveScore(bestMove,bestScore); } adaptiveBeta = max(alpha, bestScore) + 1; } } return MoveScore(bestMove,bestScore); } If someone can please help by explaining how to get this to work with a simple stack. Example code would be much appreciated. While c++ would be perfect, any language that demonstrates how would be great. Thank You.

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• WPF TextBlock refresh in real time

  - by TheOnlyBrien

  I'm new to C#, in fact, this is one of the first projects I've tried to start on my own. I am curious why the TextBlock will not refresh with the following code? The WPF window does not even show up when I add the "while" loop to the code. I just want this to have a real time display of the days since I was born. Please help me out or give me constructive direction. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace daysAliveWPF { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); DateTime myBirthday = new DateTime(1984, 01, 19); while (true) { TimeSpan daysAlive = DateTime.Now.Subtract(myBirthday); MyTextBlock.Text = daysAlive.TotalDays.ToString(); } } } } Similar code has worked in a Console Window application, so I don't understand what's going on here. Console Application code snip that did work is: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DisplayRealTime { class Program { static void Main(string[] args) { DateTime myBirthday = new DateTime(1984, 06, 19); while (true) { TimeSpan daysAlive = DateTime.Now.Subtract(myBirthday); Console.Write("\rTotal Days Alive: {0}", daysAlive.TotalDays.ToString(".#####")); } } } } Thank you!

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• How do you keep code with continuations/callbacks readable?

  - by Heinzi

  Summary: Are there some well-established best-practice patterns that I can follow to keep my code readable in spite of using asynchronous code and callbacks? I'm using a JavaScript library that does a lot of stuff asynchronously and heavily relies on callbacks. It seems that writing a simple "load A, load B, ..." method becomes quite complicated and hard to follow using this pattern. Let me give a (contrived) example. Let's say I want to load a bunch of images (asynchronously) from a remote web server. In C#/async, I'd write something like this: disableStartButton(); foreach (myData in myRepository) { var result = await LoadImageAsync("http://my/server/GetImage?" + myData.Id); if (result.Success) { myData.Image = result.Data; } else { write("error loading Image " + myData.Id); return; } } write("success"); enableStartButton(); The code layout follows the "flow of events": First, the start button is disabled, then the images are loaded (await ensures that the UI stays responsive) and then the start button is enabled again. In JavaScript, using callbacks, I came up with this: disableStartButton(); var count = myRepository.length; function loadImage(i) { if (i >= count) { write("success"); enableStartButton(); return; } myData = myRepository[i]; LoadImageAsync("http://my/server/GetImage?" + myData.Id, function(success, data) { if (success) { myData.Image = data; } else { write("error loading image " + myData.Id); return; } loadImage(i+1); } ); } loadImage(0); I think the drawbacks are obvious: I had to rework the loop into a recursive call, the code that's supposed to be executed in the end is somewhere in the middle of the function, the code starting the download (loadImage(0)) is at the very bottom, and it's generally much harder to read and follow. It's ugly and I don't like it. I'm sure that I'm not the first one to encounter this problem, so my question is: Are there some well-established best-practice patterns that I can follow to keep my code readable in spite of using asynchronous code and callbacks?

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• SQL SERVER – Weekly Series – Memory Lane – #034

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 UDF – User Defined Function to Strip HTML – Parse HTML – No Regular Expression The UDF used in the blog does fantastic task – it scans entire HTML text and removes all the HTML tags. It keeps only valid text data without HTML task. This is one of the quite commonly requested tasks many developers have to face everyday. De-fragmentation of Database at Operating System to Improve Performance Operating system skips MDF file while defragging the entire filesystem of the operating system. It is absolutely fine and there is no impact of the same on performance. Read the entire blog post for my conversation with our network engineers. Delay Function – WAITFOR clause – Delay Execution of Commands How do you delay execution of the commands in SQL Server – ofcourse by using WAITFOR keyword. In this blog post, I explain the same with the help of T-SQL script. Find Length of Text Field To measure the length of TEXT fields the function is DATALENGTH(textfield). Len will not work for text field. As of SQL Server 2005, developers should migrate all the text fields to VARCHAR(MAX) as that is the way forward. Retrieve Current Date Time in SQL Server CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} There are three ways to retrieve the current datetime in SQL SERVER. CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} Explanation and Comparison of NULLIF and ISNULL An interesting observation is NULLIF returns null if it comparison is successful, whereas ISNULL returns not null if its comparison is successful. In one way they are opposite to each other. Here is my question to you - How to create infinite loop using NULLIF and ISNULL? If this is even possible? 2008 Introduction to SERVERPROPERTY and example SERVERPROPERTY is a very interesting system function. It returns many of the system values. I use it very frequently to get different server values like Server Collation, Server Name etc. SQL Server Start Time We can use DMV to find out what is the start time of SQL Server in 2008 and later version. In this blog you can see how you can do the same. Find Current Identity of Table Many times we need to know what is the current identity of the column. I have found one of my developers using aggregated function MAX () to find the current identity. However, I prefer following DBCC command to figure out current identity. Create Check Constraint on Column Some time we just need to create a simple constraint over the table but I have noticed that developers do many different things to make table column follow rules than just creating constraint. I suggest constraint is a very useful concept and every SQL Developer should pay good attention to this subject. 2009 List Schema Name and Table Name for Database This is one of the blog post where I straight forward display script. One of the kind of blog posts, which I still love to read and write. Clustered Index on Separate Drive From Table Location A table devoid of primary key index is called heap, and here data is not arranged in a particular order, which gives rise to issues that adversely affect performance. Data must be stored in some kind of order. If we put clustered index on it then the order will be forced by that index and the data will be stored in that particular order. Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. 2010 Data Pages in Buffer Pool – Data Stored in Memory Cache One of my earlier year article, which I still read it many times and point developers to read it again. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. TRANSACTION, DML and Schema Locks Can you create a situation where you can see Schema Lock? Well, this is a very simple question, however during the interview I notice over 50 candidates failed to come up with the scenario. In this blog post, I have demonstrated the situation where we can see the schema lock in database. 2011 Solution – Puzzle – Statistics are not updated but are Created Once In this example I have created following situation: Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Auto Update Statistics and Auto Create Statistics for database is TRUE Now I have requested two things in the example 1) Why this is happening? 2) How to fix this issue? Selecting Domain from Email Address This is a straight to script blog post where I explain how to select only domain name from entire email address. Solution – Generating Zero Without using Any Numbers in T-SQL How to get zero digit without using any digit? This is indeed a very interesting question and the answer is even interesting. Try to come up with answer in next 10 minutes and if you can’t come up with the answer the blog post read this post for solution. 2012 Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. DIFFERENCE function returns an integer value. The  integer returned is the number of characters in the SOUNDEX values that are the same. Read Only Files and SQL Server Management Studio (SSMS) I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. Identifying Column Data Type of uniqueidentifier without Querying System Tables How do I know if any table has a uniqueidentifier column and what is its value without using any DMV or System Catalogues? Only information you know is the table name and you are allowed to return any kind of error if the table does not have uniqueidentifier column. Read the blog post to find the answer. Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue Interesting question – “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it?” Importing CSV File Into Database – SQL in Sixty Seconds #018 – Video Here is interesting small 60 second video on how to import CSV file into Database. ColumnStore Index – Batch Mode vs Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput. Follow up – Usage of $rowguid and $IDENTITY This is an excellent follow up blog post of my earlier blog post where I explain where to use $rowguid and $identity.  If you do not know the difference between them, this is a blog with a script example. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Simple Mouse Move Event in F# with Winforms

  - by MarkPearl

  This evening I had the pleasure of reading one of ThomasP’s blog posts on first class events. It was an excellent read, and I thought I would make a brief derivative of his post to explore some of the basics. In Thomas’s post he has a form with an ellipse on it that when he clicks on the ellipse it pops up a message box with the button clicked… awesome. Something that got me on the post though was the code similar to the one below… // React to Mouse Move events on the form let evtMessages = frm.MouseMove |> Event.map (fun mi -> mi.Location.ToString()) |> Event.map (sprintf "Hey, you clicked on the ellipse.\nUsing: %s") |> Event.add (MessageBox.Show >> ignore) The MessageBox is a function with a string passed into it. What if I wanted to rather change a mutable value holder instead, how would the syntax go for that? Immediately the thought came to me of anonymous functions. I’ve used them before to do something like this… let HelloPerson personName = "Hello " + personName |> fun(x) -> Console.WriteLine(x) So using the same approach I adapted the event code to instead of showing a Message Box with a string passed in to it, to rather change the forms header. |> Event.map (sprintf "Your mouse position is %s") |> Event.add(fun(x) -> frm.Text <- x) Okay… it looks a bit weird with the –> x <- syntax, but makes sense and works… The next thing I wanted to do was change Thomas’s code sample from having an ellipse, and reacting to the position of the mouse and click, to rather trigger the event whenever the mouse moved. This simple involved removing some filtering code. Finally I wanted the code to work as a FSharp Project without having to run through the F# interactive. To achieve this I just needed to find out how to trigger the window event loop. This can be achieved with the code below… // Program eventloop while frm.Created do Application.DoEvents()   So lets look at the complete code sample… #light open System open System.Drawing open System.Windows.Forms // Create the main form let frm = new Form(ClientSize=Size(600,400)) // React to Mouse Move events on the form let evtMessages = frm.MouseMove |> Event.map (fun mi -> mi.Location.ToString()) |> Event.map (sprintf "Your mouse position is %s") |> Event.add(fun(x) -> frm.Text <- x) // Show the form frm.Show() // Program eventloop while frm.Created do Application.DoEvents()

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• Atmospheric scattering sky from space artifacts

  - by ollipekka

  I am in the process of implementing atmospheric scattering of a planets from space. I have been using Sean O'Neil's shaders from http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter16.html as a starting point. I have pretty much the same problem related to fCameraAngle except with SkyFromSpace shader as opposed to GroundFromSpace shader as here: http://www.gamedev.net/topic/621187-sean-oneils-atmospheric-scattering/ I get strange artifacts with sky from space shader when not using fCameraAngle = 1 in the inner loop. What is the cause of these artifacts? The artifacts disappear when fCameraAngle is limtied to 1. I also seem to lack the hue that is present in O'Neil's sandbox (http://sponeil.net/downloads.htm) Camera position X=0, Y=0, Z=500. GroundFromSpace on the left, SkyFromSpace on the right. Camera position X=500, Y=500, Z=500. GroundFromSpace on the left, SkyFromSpace on the right. I've found that the camera angle seems to handled very differently depending the source: In the original shaders the camera angle in SkyFromSpaceShader is calculated as: float fCameraAngle = dot(v3Ray, v3SamplePoint) / fHeight; Whereas in ground from space shader the camera angle is calculated as: float fCameraAngle = dot(-v3Ray, v3Pos) / length(v3Pos); However, various sources online tinker with negating the ray. Why is this? Here is a C# Windows.Forms project that demonstrates the problem and that I've used to generate the images: https://github.com/ollipekka/AtmosphericScatteringTest/ Update: I have found out from the ScatterCPU project found on O'Neil's site that the camera ray is negated when the camera is above the point being shaded so that the scattering is calculated from point to the camera. Changing the ray direction indeed does remove artifacts, but introduces other problems as illustrated here: Furthermore, in the ScatterCPU project, O'Neil guards against situations where optical depth for light is less than zero: float fLightDepth = Scale(fLightAngle, fScaleDepth); if (fLightDepth < float.Epsilon) { continue; } As pointed out in the comments, along with these new artifacts this still leaves the question, what is wrong with the images where camera is positioned at 500, 500, 500? It feels like the halo is focused on completely wrong part of the planet. One would expect that the light would be closer to the spot where the sun should hits the planet, rather than where it changes from day to night. The github project has been updated to reflect changes in this update.

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• grub problem after grub-repair

  - by alireza

  I had two OS,win 7 and Ubuntu, I was working with win and went out of the room and when came back I saw Grub Rescue!!! I booted live and did grub_repaire and it still says multiple active partitions.operating system not found I feel that it can not find the ubuntu hard drive at all! ! ubuntu@ubuntu:/dev$ sudo fdisk -l Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xde771741 Device Boot Start End Blocks Id System /dev/sda1 * 61 61 0 0 Empty /dev/sda2 2048 30146559 15072256 27 Hidden NTFS WinRE /dev/sda3 * 30146560 30351359 102400 7 HPFS/NTFS/exFAT /dev/sda4 30351360 334483299 152065970 7 HPFS/NTFS/exFAT ubuntu@ubuntu:/dev$ ls autofs dvdrw loop4 ppp ram5 shm tty15 tty29 tty42 tty56 ttyS10 ttyS24 uinput vcsa1 block ecryptfs loop5 psaux ram6 snapshot tty16 tty3 tty43 tty57 ttyS11 ttyS25 urandom vcsa2 bsg fb0 loop6 ptmx ram7 snd tty17 tty30 tty44 tty58 ttyS12 ttyS26 usbmon0 vcsa3 btrfs-control fd loop7 pts ram8 sr0 tty18 tty31 tty45 tty59 ttyS13 ttyS27 usbmon1 vcsa4 bus full loop-control ram0 ram9 stderr tty19 tty32 tty46 tty6 ttyS14 ttyS28 usbmon2 vcsa5 cdrom fuse mapper ram1 random stdin tty2 tty33 tty47 tty60 ttyS15 ttyS29 v4l vcsa6 cdrw fw0 mcelog ram10 rfkill stdout tty20 tty34 tty48 tty61 ttyS16 ttyS3 vcs vcsa7 char hpet mei ram11 rtc tty tty21 tty35 tty49 tty62 ttyS17 ttyS30 vcs1 vga_arbiter console input mem ram12 rtc0 tty0 tty22 tty36 tty5 tty63 ttyS18 ttyS31 vcs2 video0 core kmsg net ram13 sda tty1 tty23 tty37 tty50 tty7 ttyS19 ttyS4 vcs3 zero cpu log network_latency ram14 sda2 tty10 tty24 tty38 tty51 tty8 ttyS2 ttyS5 vcs4 cpu_dma_latency loop0 network_throughput ram15 sda3 tty11 tty25 tty39 tty52 tty9 ttyS20 ttyS6 vcs5 disk loop1 null ram2 sda4 tty12 tty26 tty4 tty53 ttyprintk ttyS21 ttyS7 vcs6 dri loop2 oldmem ram3 sg0 tty13 tty27 tty40 tty54 ttyS0 ttyS22 ttyS8 vcs7 dvd loop3 port ram4 sg1 tty14 tty28 tty41 tty55 ttyS1 ttyS23 ttyS9 vcsa ubuntu@ubuntu:/dev$ someone said { Remove the boot flag from sda1, by typing in a terminal: sudo fdisk /dev/sda1 Then press the 'a' key, and 'Enter'. Then press the '1' key, and 'Enter'. Then press the 'w' key, and 'Enter'. } but after grub-repair I got this log: http://paste.ubuntu.com/1371297/ then I try sudo fdisk /dev/sda1 and But It says unable to open /dev/sda1! which is right as sda1 is not in dev folder (look at the picture!) Can anybody help me? I need to work on my windows for the rest of the semester and don't care of my ubuntu. thank you

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• Beware of const members

  - by nmarun

  I happened to learn a new thing about const today and how one needs to be careful with its usage. Let’s say I have a third-party assembly ‘ConstVsReadonlyLib’ with a class named ConstSideEffect.cs: 1: public class ConstSideEffect 2: { 3: public static readonly int StartValue = 10; 4: public const int EndValue = 20; 5: } In my project, I reference the above assembly as follows: 1: static void Main(string[] args) 2: { 3: for (int i = ConstSideEffect.StartValue; i < ConstSideEffect.EndValue; i++) 4: { 5: Console.WriteLine(i); 6: } 7: Console.ReadLine(); 8: } You’ll see values 10 through 19 as expected. Now, let’s say I receive a new version of the ConstVsReadonlyLib. 1: public class ConstSideEffect 2: { 3: public static readonly int StartValue = 5; 4: public const int EndValue = 30; 5: } If I just drop this new assembly in the bin folder and run the application, without rebuilding my console application, my thinking was that the output would be from 5 to 29. Of course I was wrong… if not you’d not be reading this blog. The actual output is from 5 through 19. The reason is due to the behavior of const and readonly members. To begin with, const is the compile-time constant and readonly is a runtime constant. Next, when you compile the code, a compile-time constant member is replaced with the value of the constant in the code. But, the IL generated when you reference a read-only constant, references the readonly variable, not its value. So, the IL version of the Main method, after compilation actually looks something like: 1: static void Main(string[] args) 2: { 3: for (int i = ConstSideEffect.StartValue; i < 20; i++) 4: { 5: Console.WriteLine(i); 6: } 7: Console.ReadLine(); 8: } I’m no expert with this IL thingi, but when I look at the disassembled code of the exe file (using IL Disassembler), I see the following: I see our readonly member still being referenced by the variable name (ConstVsReadonlyLib.ConstSideEffect::StartValue) in line 0001. Then there’s the Console.WriteLine in line 000b and finally, see the value of 20 in line 0017. This, I’m pretty sure is our const member being replaced by its value which marks the upper bound of the ‘for’ loop. Now you know why the output was from 5 through 19. This definitely is a side-effect of having const members and one needs to be aware of it. While we’re here, I’d like to add a few other points about const and readonly members: const is slightly faster, but is less flexible readonly cannot be declared within a method scope const can be used only on primitive types (numbers and strings) Just wanted to share this before going to bed!

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• How to store generated eigen faces for future face recognition?

  - by user3237134

  My code works in the following manner: 1.First, it obtains several images from the training set 2.After loading these images, we find the normalized faces,mean face and perform several calculation. 3.Next, we ask for the name of an image we want to recognize 4.We then project the input image into the eigenspace, and based on the difference from the eigenfaces we make a decision. 5.Depending on eigen weight vector for each input image we make clusters using kmeans command. Source code i tried: clear all close all clc % number of images on your training set. M=1200; %Chosen std and mean. %It can be any number that it is close to the std and mean of most of the images. um=60; ustd=32; %read and show images(bmp); S=[]; %img matrix for i=1:M str=strcat(int2str(i),'.jpg'); %concatenates two strings that form the name of the image eval('img=imread(str);'); [irow icol d]=size(img); % get the number of rows (N1) and columns (N2) temp=reshape(permute(img,[2,1,3]),[irow*icol,d]); %creates a (N1*N2)x1 matrix S=[S temp]; %X is a N1*N2xM matrix after finishing the sequence %this is our S end %Here we change the mean and std of all images. We normalize all images. %This is done to reduce the error due to lighting conditions. for i=1:size(S,2) temp=double(S(:,i)); m=mean(temp); st=std(temp); S(:,i)=(temp-m)*ustd/st+um; end %show normalized images for i=1:M str=strcat(int2str(i),'.jpg'); img=reshape(S(:,i),icol,irow); img=img'; end %mean image; m=mean(S,2); %obtains the mean of each row instead of each column tmimg=uint8(m); %converts to unsigned 8-bit integer. Values range from 0 to 255 img=reshape(tmimg,icol,irow); %takes the N1*N2x1 vector and creates a N2xN1 matrix img=img'; %creates a N1xN2 matrix by transposing the image. % Change image for manipulation dbx=[]; % A matrix for i=1:M temp=double(S(:,i)); dbx=[dbx temp]; end %Covariance matrix C=A'A, L=AA' A=dbx'; L=A*A'; % vv are the eigenvector for L % dd are the eigenvalue for both L=dbx'*dbx and C=dbx*dbx'; [vv dd]=eig(L); % Sort and eliminate those whose eigenvalue is zero v=[]; d=[]; for i=1:size(vv,2) if(dd(i,i)>1e-4) v=[v vv(:,i)]; d=[d dd(i,i)]; end end %sort, will return an ascending sequence [B index]=sort(d); ind=zeros(size(index)); dtemp=zeros(size(index)); vtemp=zeros(size(v)); len=length(index); for i=1:len dtemp(i)=B(len+1-i); ind(i)=len+1-index(i); vtemp(:,ind(i))=v(:,i); end d=dtemp; v=vtemp; %Normalization of eigenvectors for i=1:size(v,2) %access each column kk=v(:,i); temp=sqrt(sum(kk.^2)); v(:,i)=v(:,i)./temp; end %Eigenvectors of C matrix u=[]; for i=1:size(v,2) temp=sqrt(d(i)); u=[u (dbx*v(:,i))./temp]; end %Normalization of eigenvectors for i=1:size(u,2) kk=u(:,i); temp=sqrt(sum(kk.^2)); u(:,i)=u(:,i)./temp; end % show eigenfaces; for i=1:size(u,2) img=reshape(u(:,i),icol,irow); img=img'; img=histeq(img,255); end % Find the weight of each face in the training set. omega = []; for h=1:size(dbx,2) WW=[]; for i=1:size(u,2) t = u(:,i)'; WeightOfImage = dot(t,dbx(:,h)'); WW = [WW; WeightOfImage]; end omega = [omega WW]; end % Acquire new image % Note: the input image must have a bmp or jpg extension. % It should have the same size as the ones in your training set. % It should be placed on your desktop ed_min=[]; srcFiles = dir('G:\newdatabase\*.jpg'); % the folder in which ur images exists for b = 1 : length(srcFiles) filename = strcat('G:\newdatabase\',srcFiles(b).name); Imgdata = imread(filename); InputImage=Imgdata; InImage=reshape(permute((double(InputImage)),[2,1,3]),[irow*icol,1]); temp=InImage; me=mean(temp); st=std(temp); temp=(temp-me)*ustd/st+um; NormImage = temp; Difference = temp-m; p = []; aa=size(u,2); for i = 1:aa pare = dot(NormImage,u(:,i)); p = [p; pare]; end InImWeight = []; for i=1:size(u,2) t = u(:,i)'; WeightOfInputImage = dot(t,Difference'); InImWeight = [InImWeight; WeightOfInputImage]; end noe=numel(InImWeight); % Find Euclidean distance e=[]; for i=1:size(omega,2) q = omega(:,i); DiffWeight = InImWeight-q; mag = norm(DiffWeight); e = [e mag]; end ed_min=[ed_min MinimumValue]; theta=6.0e+03; %disp(e) z(b,:)=InImWeight; end IDX = kmeans(z,5); clustercount=accumarray(IDX, ones(size(IDX))); disp(clustercount); QUESTIONS: 1.It is working fine for M=50(i.e Training set contains 50 images) but not for M=1200(i.e Training set contains 1200 images).It is not showing any error.There is no output.I waited for 10 min still there is no output. I think it is going infinite loop.What is the problem?Where i was wrong? 2.Instead of running the training set everytime how eigen faces generated are stored so that stored eigen faces are used for future face recoginition for a new input image.So it reduces wastage of time.

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