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• System won't boot: Gigabyte HD 7790 1GB OC GPU issue or Corsair VS550 PSU issue?

  - by MGOwen

  Installed a new GPU, and PC won't boot. Turn it on and: No monitor signal at all (tried HDMI and VGA via DVI, on 2 working monitors). CPU and GPU fans DO spin, but No system beeps, no sounds from drives (they might make a small noise in the first 1 second or so, but there's definitely no OS loading or anything like that) If hit "power off" button it turns off immediately (no holding down for 3 seconds like usual) If I put my old HD 5670 GPU back in, everything works fine. But (plot twist!) card is not totally dead. My friend put it in his PC, and it works fine (he even played a game for 15 minutes, no issues). He has a Corsair TX850 850W and a Gigabyte MB. So my main theory is: the GPU isn't getting enough power from the PSU. But is it: Bad PSU? Seems unlikely, since it works fine with the other GPU. Also, the PSU Is brand new and 550W (single 42A/504W 12V rail). Overkill for this GPU. Corsair is a decent brand, but maybe just mine is faulty? Bad GPU? Could it be drawing more power than it should be, somehow, or something? Supposedly HD 7790 needs only 21A/75W on the 12v rail, though this one is factory overclocked a bit... but should that triple the power requirement? Something else? Could there be a motherboard incompatibility somehow? Both MB and GPU are less than a year old and PCI Express 3.0 x16. Things I've tried: Re-seating the video card Testing PC with old GPU (works fine, same PCIe slot). Checked AMD's stated amp/watt requirements of a 7790 and my PSU (see above). My PSU can output twice the amps (single rail) and 5x the Wattage a 7790 needs. Here are the full specs: Gigabyte HD 7790 1GB OC GPU Corsair VS550 550W PSU 4GB RAM AsRock H61M U3S3 motherboard i3-2100 500GB SATA HDD (2007-ish) blu-ray drive (new) PCI 802.11g card Edit: Motherboard BIOS Update seems to have fixed it. (If anyone has same problem and it doesn't work, comment here).

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• Does Test Driven Development (TDD) improve Quality and Correctness? (Part 1)

  - by David V. Corbin

  Since the dawn of the computer age, various methodologies have been introduced to improve quality and reduce cost. In this posting, I will by sharing my experiences with Test Driven Development; both its benefits and limitations. To start this topic, we need to agree on what TDD is. The first is to define each of the three words as used in this context. Test - An item or action which measures something in some quantifiable form. Driven - The primary motivation or focus of a series of activities (process) Development - All phases of a software project/product from concept through delivery. The above are very simple definitions that result in the following: "TDD is a process where the primary focus is on measuring and quantifying all aspects of the creation of a (software) product." There are many places where TDD is used outside of software development, even though it is not known by this name. Consider the (conventional) education process that most of us grew up on. The focus was to get the best grades as measured by different tests. Many of these tests measured rote memorization and not understanding of the subject matter. The result of this that many people graduated with high scores but without "quality and correctness" in their ability to utilize the subject matter (of course, the flip side is true where certain people DID understand the material but were not very good at taking this type of test). Returning to software development, let us look at some common scenarios. While these items are generally applicable regardless of platform, language and tools; the remainder of this post will utilize Microsoft Visual Studio and Team Foundation Server (TFS) for examples. It should be realized that everyone does at least some aspect of TDD. At the most rudimentary level, getting a program to compile involves a "pass/fail" measurement (is the syntax valid) that drives their ability to proceed further (run the program). Other developers may create "Unit Tests" in the belief that having a test for every method/property of a class and good code coverage is the goal of TDD. These items may be helpful and even important, but really only address a small aspect of the overall effort. To see TDD in a bigger view, lets identify the various activities that are part of the Software Development LifeCycle. These are going to be presented in a Waterfall style for simplicity, but each item also occurs within Iterative methodologies such as Agile/Scrum. the key ones here are: Requirements Gathering Architecture Design Implementation Quality Assurance Can each of these items be subjected to a process which establishes metrics (quantified metrics) that reflect both the quality and correctness of each item? It should be clear that conventional Unit Tests do not apply to all of these items; at best they can verify that a local aspect (e.g. a Class/Method) of implementation matches the (test writers perspective of) the appropriate design document. So what can we do? For each of area, the goal is to create tests that are quantifiable and durable. The ability to quantify the measurements (beyond a simple pass/fail) is critical to tracking progress(eventually measuring the level of success that has been achieved) and for providing clear information on what items need to be addressed (along with the appropriate time to address them - in varying levels of detail) . Durability is important so that the test can be reapplied (ideally in an automated fashion) over the entire cycle. Returning for a moment back to our "education example", one must also be careful of how the tests are organized and how the measurements are taken. If a test is in a multiple choice format, there is a significant statistical probability that a correct answer might be the result of a random guess. Also, in many situations, having the student simply provide a final answer can obscure many important elements. For example, on a math test, having the student simply provide a numeric answer (rather than showing the methodology) may result in a complete mismatch between the process and the result. It is hard to determine which is worse: The student who makes a simple arithmetric error at one step of a long process (resulting in a wrong answer) or The student who (without providing the "workflow") uses a completely invalid approach, yet still comes up with the right number. The "Wrong Process"/"Right Answer" is probably the single biggest problem in software development. Even very simple items can suffer from this. As an example consider the following code for a "straight line" calculation....Is it correct? (for Integral Points)         int Solve(int m, int b, int x) { return m * x + b; }   Most people would respond "Yes". But let's take the question one step further... Is it correct for all possible values of m,b,x??? (no fair if you cheated by being focused on the bolded text!)  Without additional information regarding constrains on "the possible values of m,b,x" the answer must be NO, there is the risk of overflow/wraparound that will produce an incorrect result! To properly answer this question (i.e. Test the Code), one MUST be able to backtrack from the implementation through the design, and architecture all the way back to the requirements. And the requirement itself must be tested against the stakeholder(s). It is only when the bounding conditions are defined that it is possible to determine if the code is "Correct" and has "Quality". Yet, how many of us (myself included) have written such code without even thinking about it. In many canses we (think we) "know" what the bounds are, and that the code will be correct. As we all know, requirements change, "code reuse" causes implementations to be applied to different scenarios, etc. This leads directly to the types of system failures that plague so many projects. This approach to TDD is much more holistic than ones which start by focusing on the details. The fundamental concepts still apply: Each item should be tested. The test should be defined/implemented before (or concurrent with) the definition/implementation of the actual item. We also add concepts that expand the scope and alter the style by recognizing: There are many things beside "lines of code" that benefit from testing (measuring/evaluating in a formal way) Correctness and Quality can not be solely measured by "correct results" In the future parts, we will examine in greater detail some of the techniques that can be applied to each of these areas....

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• Deterministic/Consistent Unique Masking

  - by Dinesh Rajasekharan-Oracle

  One of the key requirements while masking data in large databases or multi database environment is to consistently mask some columns, i.e. for a given input the output should always be the same. At the same time the masked output should not be predictable. Deterministic masking also eliminates the need to spend enormous amount of time spent in identifying data relationships, i.e. parent and child relationships among columns defined in the application tables. In this blog post I will explain different ways of consistently masking the data across databases using Oracle Data Masking and Subsetting The readers of post should have minimal knowledge on Oracle Enterprise Manager 12c, Application Data Modeling, Data Masking concepts. For more information on these concepts, please refer to Oracle Data Masking and Subsetting document Oracle Data Masking and Subsetting 12c provides four methods using which users can consistently yet irreversibly mask their inputs. 1. Substitute 2. SQL Expression 3. Encrypt 4. User Defined Function SUBSTITUTE The substitute masking format replaces the original value with a value from a pre-created database table. As the method uses a hash based algorithm in the back end the mappings are consistent. For example consider DEPARTMENT_ID in EMPLOYEES table is replaced with FAKE_DEPARTMENT_ID from FAKE_TABLE. The substitute masking transformation that all occurrences of DEPARTMENT_ID say ‘101’ will be replaced with ‘502’ provided same substitution table and column is used , i.e. FAKE_TABLE.FAKE_DEPARTMENT_ID. The following screen shot shows the usage of the Substitute masking format with in a masking definition: Note that the uniqueness of the masked value depends on the number of columns being used in the substitution table i.e. if the original table contains 50000 unique values, then for the masked output to be unique and deterministic the substitution column should also contain 50000 unique values without which only consistency is maintained but not uniqueness. SQL EXPRESSION SQL Expression replaces an existing value with the output of a specified SQL Expression. For example while masking an EMPLOYEES table the EMAIL_ID of an employee has to be in the format EMPLOYEE’s [email protected] while FIRST_NAME and LAST_NAME are the actual column names of the EMPLOYEES table then the corresponding SQL Expression will look like %FIRST_NAME%||’.’||%LAST_NAME%||’@COMPANY.COM’. The advantage of this technique is that if you are masking FIRST_NAME and LAST_NAME of the EMPLOYEES table than the corresponding EMAIL ID will be replaced accordingly by the masking scripts. One of the interesting aspect’s of a SQL Expressions is that you can use sub SQL expressions, which means that you can write a nested SQL and use it as SQL Expression to address a complex masking business use cases. SQL Expression can also be used to consistently replace value with hashed value using Oracle’s PL/SQL function ORA_HASH. The following SQL Expression will help in the previous example for replacing the DEPARTMENT_IDs with a hashed number ORA_HASH (%DEPARTMENT_ID%, 1000) The following screen shot shows the usage of encrypt masking format with in the masking definition: ORA_HASH takes three arguments: 1. Expression which can be of any data type except LONG, LOB, User Defined Type [nested table type is allowed]. In the above example I used the Original value as expression. 2. Number of hash buckets which can be number between 0 and 4294967295. The default value is 4294967295. You can also co-relate the number of hash buckets to a range of numbers. In the above example above the bucket value is specified as 1000, so the end result will be a hashed number in between 0 and 1000. 3. Seed, can be any number which decides the consistency, i.e. for a given seed value the output will always be same. The default seed is 0. In the above SQL Expression a seed in not specified, so it to 0. If you have to use a non default seed then the function will look like. ORA_HASH (%DEPARTMENT_ID%, 1000, 1234 The uniqueness depends on the input and the number of hash buckets used. However as ORA_HASH uses a 32 bit algorithm, considering birthday paradox or pigeonhole principle there is a 0.5 probability of collision after 232-1 unique values. ENCRYPT Encrypt masking format uses a blend of 3DES encryption algorithm, hashing, and regular expression to produce a deterministic and unique masked output. The format of the masked output corresponds to the specified regular expression. As this technique uses a key [string] to encrypt the data, the same string can be used to decrypt the data. The key also acts as seed to maintain consistent outputs for a given input. The following screen shot shows the usage of encrypt masking format with in the masking definition: Regular Expressions may look complex for the first time users but you will soon realize that it’s a simple language. There are many resources in internet, oracle documentation, oracle learning library, my oracle support on writing a Regular Expressions, out of all the following My Oracle Support document helped me to get started with Regular Expressions: Oracle SQL Support for Regular Expressions[Video](Doc ID 1369668.1) USER DEFINED FUNCTION [UDF] User Defined Function or UDF provides flexibility for the users to code their own masking logic in PL/SQL, which can be called from masking Defintion. The standard format of an UDF in Oracle Data Masking and Subsetting is: Function udf_func (rowid varchar2, column_name varchar2, original_value varchar2) returns varchar2; Where • rowid is the row identifier of the column that needs to be masked • column_name is the name of the column that needs to be masked • original_value is the column value that needs to be masked You can achieve deterministic masking by using Oracle’s built in hash functions like, ORA_HASH, DBMS_CRYPTO.MD4, DBMS_CRYPTO.MD5, DBMS_UTILITY. GET_HASH_VALUE.Please refers to the Oracle Database Documentation for more information on the Oracle Hash functions. For example the following masking UDF generate deterministic unique hexadecimal values for a given string input: CREATE OR REPLACE FUNCTION RD_DUX (rid varchar2, column_name varchar2, orig_val VARCHAR2) RETURN VARCHAR2 DETERMINISTIC PARALLEL_ENABLE IS stext varchar2 (26); no_of_characters number(2); BEGIN no_of_characters:=6; stext:=substr(RAWTOHEX(DBMS_CRYPTO.HASH(UTL_RAW.CAST_TO_RAW(text),1)),0,no_of_characters); RETURN stext; END; The uniqueness depends on the input and length of the string and number of bits used by hash algorithm. In the above function MD4 hash is used [denoted by argument 1 in the DBMS_CRYPTO.HASH function which is a 128 bit algorithm which produces 2^128-1 unique hashed values , however this is limited by the length of the input string which is 6, so only 6^6 unique values will be generated. Also do not forget about the birthday paradox/pigeonhole principle mentioned earlier in this post. An another example is to consistently replace characters or numbers preserving the length and special characters as shown below: CREATE OR REPLACE FUNCTION RD_DUS(rid varchar2,column_name varchar2,orig_val VARCHAR2) RETURN VARCHAR2 DETERMINISTIC PARALLEL_ENABLE IS stext varchar2(26); BEGIN DBMS_RANDOM.SEED(orig_val); stext:=TRANSLATE(orig_val,'ABCDEFGHILKLMNOPQRSTUVWXYZ',DBMS_RANDOM.STRING('U',26)); stext:=TRANSLATE(stext,'abcdefghijklmnopqrstuvwxyz',DBMS_RANDOM.STRING('L',26)); stext:=TRANSLATE(stext,'0123456789',to_char(DBMS_RANDOM.VALUE(1,9))); stext:=REPLACE(stext,'.','0'); RETURN stext; END; The following screen shot shows the usage of an UDF with in a masking definition: To summarize, Oracle Data Masking and Subsetting helps you to consistently mask data across databases using one or all of the methods described in this post. It saves the hassle of identifying the parent-child relationships defined in the application table. Happy Masking

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• SQL Server Developer Tools &ndash; Codename Juneau vs. Red-Gate SQL Source Control

  - by Ajarn Mark Caldwell

  So how do the new SQL Server Developer Tools (previously code-named Juneau) stack up against SQL Source Control?  Read on to find out. At the PASS Community Summit a couple of weeks ago, it was announced that the previously code-named Juneau software would be released under the name of SQL Server Developer Tools with the release of SQL Server 2012.  This replacement for Database Projects in Visual Studio (also known in a former life as Data Dude) has some great new features.  I won’t attempt to describe them all here, but I will applaud Microsoft for making major improvements.  One of my favorite changes is the way database elements are broken down.  Previously every little thing was in its own file.  For example, indexes were each in their own file.  I always hated that.  Now, SSDT uses a pattern similar to Red-Gate’s and puts the indexes and keys into the same file as the overall table definition. Of course there are really cool features to keep your database model in sync with the actual source scripts, and the rename refactoring feature is now touted as being more than just a search and replace, but rather a “semantic-aware” search and replace.  Funny, it reminds me of SQL Prompt’s Smart Rename feature.  But I’m not writing this just to criticize Microsoft and argue that they are late to the party with this feature set.  Instead, I do see it as a viable alternative for folks who want all of their source code to be version controlled, but there are a couple of key trade-offs that you need to know about when you choose which tool set to use. First, the basics Both tool sets integrate with a wide variety of source control systems including the most popular: Subversion, GIT, Vault, and Team Foundation Server.  Both tools have integrated functionality to produce objects to upgrade your target database when you are ready (DACPACs in SSDT, integration with SQL Compare for SQL Source Control).  If you regularly live in Visual Studio or the Business Intelligence Development Studio (BIDS) then SSDT will likely be comfortable for you.  Like BIDS, SSDT is a Visual Studio Project Type that comes with SQL Server, and if you don’t already have Visual Studio installed, it will install the shell for you.  If you already have Visual Studio 2010 installed, then it will just add this as an available project type.  On the other hand, if you regularly live in SQL Server Management Studio (SSMS) then you will really enjoy the SQL Source Control integration from within SSMS.  Both tool sets store their database model in script files.  In SSDT, these are on your file system like other source files; in SQL Source Control, these are stored in the folder structure in your source control system, and you can always GET them to your file system if you want to browse them directly. For me, the key differentiating factors are 1) a single, unified check-in, and 2) migration scripts.  How you value those two features will likely make your decision for you. Unified Check-In If you do a continuous-integration (CI) style of development that triggers an automated build with unit testing on every check-in of source code, and you use Visual Studio for the rest of your development, then you will want to really consider SSDT.  Because it is just another project in Visual Studio, it can be added to your existing Solution, and you can then do a complete, or unified single check-in of all changes whether they are application or database changes.  This is simply not possible with SQL Source Control because it is in a different development tool (SSMS instead of Visual Studio) and there is no way to do one unified check-in between the two.  You CAN do really fast back-to-back check-ins, but there is the possibility that the automated build that is triggered from the first check-in will cause your unit tests to fail and the CI tool to report that you broke the build.  Of course, the automated build that is triggered from the second check-in which contains the “other half” of your changes should pass and so the amount of time that the build was broken may be very, very short, but if that is very, very important to you, then SQL Source Control just won’t work; you’ll have to use SSDT. Refactoring and Migrations If you work on a mature system, or on a not-so-mature but also not-so-well-designed system, where you want to refactor the database schema as you go along, but you can’t have data suddenly disappearing from your target system, then you’ll probably want to go with SQL Source Control.  As I wrote previously, there are a number of changes which you can make to your database that the comparison tools (both from Microsoft and Red Gate) simply cannot handle without the possibility (or probability) of data loss.  Currently, SSDT only offers you the ability to inject PRE and POST custom deployment scripts.  There is no way to insert your own script in the middle to override the default behavior of the tool.  In version 3.0 of SQL Source Control (Early Access version now available) you have that ability to create your own custom migration script to take the place of the commands that the tool would have done, and ensure the preservation of your data.  Or, even if the default tool behavior would have worked, but you simply know a better way then you can take control and do things your way instead of theirs. You Decide In the environment I work in, our automated builds are not triggered off of check-ins, but off of the clock (currently once per night) and so there is no point at which the automated build and unit tests will be triggered without having both sides of the development effort already checked-in.  Therefore having a unified check-in, while handy, is not critical for us.  As for migration scripts, these are critically important to us.  We do a lot of new development on systems that have already been in production for years, and it is not uncommon for us to need to do a refactoring of the database.  Because of the maturity of the existing system, that often involves data migrations or other additional SQL tasks that the comparison tools just can’t detect on their own.  Therefore, the ability to create a custom migration script to override the tool’s default behavior is very important to us.  And so, you can see why we will continue to use Red Gate SQL Source Control for the foreseeable future.

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• SanjayP&rsquo;s venture after Microsoft involves no Microsoft

  - by eddraper

  When I was at Microsoft, I always found Sanjay Parthasarathy to be a bright and passionate leader.  While he was a bit disconnected at times with what was really going on out in the trenches, I always thought he was true believer in what we in Developer Platform and Evangelism (DPE) were doing.  He got it.  He had started DPE and kicked a lot of doors down up in Redmond to make it happen.  Back in the early 2000s, battles over platform choices at large customers was trench warfare… bayonets and hand grenades at the P-Code level.  This model was not at all suited to Microsoft’s org structure at the time.  While there were plenty of people fully able to have competitive conversations around Windows Server, or AD, or Exchange, or the desktop, there weren’t many that could have deep technical conversations around Java vs .NET and the platform “stack” as a cohesive, unified unit of value.  This task fell to DPE. Sanjay ended up leaving Microsoft a number of months before me in 2009 and I remember thinking these exact words: “holy shit, SanjayP left Microsoft.”  When SanjayP left DPE years before that,  Sheila Gulati had stepped into his shoes and I thought we where starting to miss a beat.  Sheila had built an amazing business at Microsoft India, but I don’t recall being inspired by her as a leader.  SanjayP’s talks felt like the opening scene of “Patton” with George C. Scott pacing in front of the American flag.  Sheila was a voice on a con-call.  When she moved on in 2007, Walid Abu-Hadba was given the reigns.  Personally, I don’t ever recall even seeing his face.  I think I might recall hearing his voice on some con-calls, but for all intents and purposes he was invisible to me.  Perhaps this was the beginning of my carelessness around seeking “visibility.” Fast forward to Build 2011.  First off, we have no PDC – we have Build.  Microsoft had made an 11 year investment by this time in building an organization to make its technology relevant to developers.  One would think such an org would be in the driver’s seat of such an event, but we see Windows product group people on the podiums.  Watching, I could see the messaging unfold… but no story.  It was like the old days.  Demos and PowerPoints by team members building the tech, and in many cases VPs.  The ensuing confusion is almost legendary now.  Windows 8 was, and is, a pretty big deal… but who is telling the story – not just features and benefits, but the story around how it all fits together. Having been out of Microsoft for two years now, and looking in, I can only conclude that the “DPE of old” has at best been emasculated, and at worst been completely marginalized by internal politics, or perhaps the eternal march of the corporate entropy generator that resides at all large companies.  I don’t think this is a good thing for anyone. And now, back to Sanjay who is the father of Microsoft DPE… I noticed that he has moved back to India and is doing start-up work.  His current company Indix looks to be doing some interesting things with “big data” and here’s their stack: Nary a trace of anything Microsoft.  What could account for this?  I wonder….  Better availability of labor and expertise in India for this stack?  Donno, but even in India, leet R and Hadoop skills have to be hard to find. Technical superiority?  This, I sincerely doubt. This stack, with SanjayP’s name as CEO leaves me with an unsettling feeling.  If he did believe, he no longer does.  One doesn’t place bets with real money on things they don’t believe in.  Perhaps he never did believe, and was a corporate creature seeking to find a niche for himself after which he manipulated me and others.  Or perhaps… anger… be it passive aggression or an outright “in your face F*** you” to his former masters. I guess in the end, only he knows the true reason… But I have my theory...

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• Performance considerations for common SQL queries

  - by Jim Giercyk

  Originally posted on: http://geekswithblogs.net/NibblesAndBits/archive/2013/10/16/performance-considerations-for-common-sql-queries.aspxSQL offers many different methods to produce the same results.  There is a never-ending debate between SQL developers as to the “best way” or the “most efficient way” to render a result set.  Sometimes these disputes even come to blows….well, I am a lover, not a fighter, so I decided to collect some data that will prove which way is the best and most efficient.  For the queries below, I downloaded the test database from SQLSkills:  http://www.sqlskills.com/sql-server-resources/sql-server-demos/.  There isn’t a lot of data, but enough to prove my point: dbo.member has 10,000 records, and dbo.payment has 15,554.  Our result set contains 6,706 records. The following queries produce an identical result set; the result set contains aggregate payment information for each member who has made more than 1 payment from the dbo.payment table and the first and last name of the member from the dbo.member table.   /*************/ /* Sub Query  */ /*************/ SELECT  a.[Member Number] ,         m.lastname ,         m.firstname ,         a.[Number Of Payments] ,         a.[Average Payment] ,         a.[Total Paid] FROM    ( SELECT    member_no 'Member Number' ,                     AVG(payment_amt) 'Average Payment' ,                     SUM(payment_amt) 'Total Paid' ,                     COUNT(Payment_No) 'Number Of Payments'           FROM      dbo.payment           GROUP BY  member_no           HAVING    COUNT(Payment_No) > 1         ) a         JOIN dbo.member m ON a.[Member Number] = m.member_no         /***************/ /* Cross Apply  */ /***************/ SELECT  ca.[Member Number] ,         m.lastname ,         m.firstname ,         ca.[Number Of Payments] ,         ca.[Average Payment] ,         ca.[Total Paid] FROM    dbo.member m         CROSS APPLY ( SELECT    member_no 'Member Number' ,                                 AVG(payment_amt) 'Average Payment' ,                                 SUM(payment_amt) 'Total Paid' ,                                 COUNT(Payment_No) 'Number Of Payments'                       FROM      dbo.payment                       WHERE     member_no = m.member_no                       GROUP BY  member_no                       HAVING    COUNT(Payment_No) > 1                     ) ca /********/                    /* CTEs  */ /********/ ; WITH    Payments           AS ( SELECT   member_no 'Member Number' ,                         AVG(payment_amt) 'Average Payment' ,                         SUM(payment_amt) 'Total Paid' ,                         COUNT(Payment_No) 'Number Of Payments'                FROM     dbo.payment                GROUP BY member_no                HAVING   COUNT(Payment_No) > 1              ),         MemberInfo           AS ( SELECT   p.[Member Number] ,                         m.lastname ,                         m.firstname ,                         p.[Number Of Payments] ,                         p.[Average Payment] ,                         p.[Total Paid]                FROM     dbo.member m                         JOIN Payments p ON m.member_no = p.[Member Number]              )     SELECT  *     FROM    MemberInfo /************************/ /* SELECT with Grouping   */ /************************/ SELECT  p.member_no 'Member Number' ,         m.lastname ,         m.firstname ,         COUNT(Payment_No) 'Number Of Payments' ,         AVG(payment_amt) 'Average Payment' ,         SUM(payment_amt) 'Total Paid' FROM    dbo.payment p         JOIN dbo.member m ON m.member_no = p.member_no GROUP BY p.member_no ,         m.lastname ,         m.firstname HAVING  COUNT(Payment_No) > 1   We can see what is going on in SQL’s brain by looking at the execution plan.  The Execution Plan will demonstrate which steps and in what order SQL executes those steps, and what percentage of batch time each query takes.  SO….if I execute all 4 of these queries in a single batch, I will get an idea of the relative time SQL takes to execute them, and how it renders the Execution Plan.  We can settle this once and for all.  Here is what SQL did with these queries:   Not only did the queries take the same amount of time to execute, SQL generated the same Execution Plan for each of them.  Everybody is right…..I guess we can all finally go to lunch together!  But wait a second, I may not be a fighter, but I AM an instigator.     Let’s see how a table variable stacks up.  Here is the code I executed: /********************/ /*  Table Variable  */ /********************/ DECLARE @AggregateTable TABLE     (       member_no INT ,       AveragePayment MONEY ,       TotalPaid MONEY ,       NumberOfPayments MONEY     ) INSERT  @AggregateTable         SELECT  member_no 'Member Number' ,                 AVG(payment_amt) 'Average Payment' ,                 SUM(payment_amt) 'Total Paid' ,                 COUNT(Payment_No) 'Number Of Payments'         FROM    dbo.payment         GROUP BY member_no         HAVING  COUNT(Payment_No) > 1   SELECT  at.member_no 'Member Number' ,         m.lastname ,         m.firstname ,         at.NumberOfPayments 'Number Of Payments' ,         at.AveragePayment 'Average Payment' ,         at.TotalPaid 'Total Paid' FROM    @AggregateTable at         JOIN dbo.member m ON m.member_no = at.member_no In the interest of keeping things in groupings of 4, I removed the last query from the previous batch and added the table variable query.  Here’s what I got:     Since we first insert into the table variable, then we read from it, the Execution Plan renders 2 steps.  BUT, the combination of the 2 steps is only 22% of the batch.  It is actually faster than the other methods even though it is treated as 2 separate queries in the Execution Plan.  The argument I often hear against Table Variables is that SQL only estimates 1 row for the table size in the Execution Plan.  While this is true, the estimate does not come in to play until you read from the table variable.  In this case, the table variable had 6,706 rows, but it still outperformed the other queries.  People argue that table variables should only be used for hash or lookup tables.  The fact is, you have control of what you put IN to the variable, so as long as you keep it within reason, these results suggest that a table variable is a viable alternative to sub-queries. If anyone does volume testing on this theory, I would be interested in the results.  My suspicion is that there is a breaking point where efficiency goes down the tubes immediately, and it would be interesting to see where the threshold is. Coding SQL is a matter of style.  If you’ve been around since they introduced DB2, you were probably taught a little differently than a recent computer science graduate.  If you have a company standard, I strongly recommend you follow it.    If you do not have a standard, generally speaking, there is no right or wrong answer when talking about the efficiency of these types of queries, and certainly no hard-and-fast rule.  Volume and infrastructure will dictate a lot when it comes to performance, so your results may vary in your environment.  Download the database and try it!

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• Partition Wise Joins

  - by jean-pierre.dijcks

  Some say they are the holy grail of parallel computing and PWJ is the basis for a shared nothing system and the only join method that is available on a shared nothing system (yes this is oversimplified!). The magic in Oracle is of course that is one of many ways to join data. And yes, this is the old flexibility vs. simplicity discussion all over, so I won't go there... the point is that what you must do in a shared nothing system, you can do in Oracle with the same speed and methods. The Theory A partition wise join is a join between (for simplicity) two tables that are partitioned on the same column with the same partitioning scheme. In shared nothing this is effectively hard partitioning locating data on a specific node / storage combo. In Oracle is is logical partitioning. If you now join the two tables on that partitioned column you can break up the join in smaller joins exactly along the partitions in the data. Since they are partitioned (grouped) into the same buckets, all values required to do the join live in the equivalent bucket on either sides. No need to talk to anyone else, no need to redistribute data to anyone else... in short, the optimal join method for parallel processing of two large data sets. PWJ's in Oracle Since we do not hard partition the data across nodes in Oracle we use the Partitioning option to the database to create the buckets, then set the Degree of Parallelism (or run Auto DOP - see here) and get our PWJs. The main questions always asked are: How many partitions should I create? What should my DOP be? In a shared nothing system the answer is of course, as many partitions as there are nodes which will be your DOP. In Oracle we do want you to look at the workload and concurrency, and once you know that to understand the following rules of thumb. Within Oracle we have more ways of joining of data, so it is important to understand some of the PWJ ideas and what it means if you have an uneven distribution across processes. Assume we have a simple scenario where we partition the data on a hash key resulting in 4 hash partitions (H1 -H4). We have 2 parallel processes that have been tasked with reading these partitions (P1 - P2). The work is evenly divided assuming the partitions are the same size and we can scan this in time t1 as shown below. Now assume that we have changed the system and have a 5th partition but still have our 2 workers P1 and P2. The time it takes is actually 50% more assuming the 5th partition has the same size as the original H1 - H4 partitions. In other words to scan these 5 partitions, the time t2 it takes is not 1/5th more expensive, it is a lot more expensive and some other join plans may now start to look exciting to the optimizer. Just to post the disclaimer, it is not as simple as I state it here, but you get the idea on how much more expensive this plan may now look... Based on this little example there are a few rules of thumb to follow to get the partition wise joins. First, choose a DOP that is a factor of two (2). So always choose something like 2, 4, 8, 16, 32 and so on... Second, choose a number of partitions that is larger or equal to 2* DOP. Third, make sure the number of partitions is divisible through 2 without orphans. This is also known as an even number... Fourth, choose a stable partition count strategy, which is typically hash, which can be a sub partitioning strategy rather than the main strategy (range - hash is a popular one). Fifth, make sure you do this on the join key between the two large tables you want to join (and this should be the obvious one...). Translating this into an example: DOP = 8 (determined based on concurrency or by using Auto DOP with a cap due to concurrency) says that the number of partitions >= 16. Number of hash (sub) partitions = 32, which gives each process four partitions to work on. This number is somewhat arbitrary and depends on your data and system. In this case my main reasoning is that if you get more room on the box you can easily move the DOP for the query to 16 without repartitioning... and of course it makes for no leftovers on the table... And yes, we recommend up-to-date statistics. And before you start complaining, do read this post on a cool way to do stats in 11.

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• Independence Day for Software Components &ndash; Loosening Coupling by Reducing Connascence

  - by Brian Schroer

  Today is Independence Day in the USA, which got me thinking about loosely-coupled “independent” software components. I was reminded of a video I bookmarked quite a while ago of Jim Weirich’s “Grand Unified Theory of Software Design” talk at MountainWest RubyConf 2009. I finally watched that video this morning. I highly recommend it. In the video, Jim talks about software connascence. The dictionary definition of connascence (con-NAY-sense) is: 1. The common birth of two or more at the same time 2. That which is born or produced with another. 3. The act of growing together. The brief Wikipedia page about Connascent Software Components says that: Two software components are connascent if a change in one would require the other to be modified in order to maintain the overall correctness of the system. Connascence is a way to characterize and reason about certain types of complexity in software systems. The term was introduced to the software world in Meilir Page-Jones’ 1996 book “What Every Programmer Should Know About Object-Oriented Design”. The middle third of that book is the author’s proposed graphical notation for describing OO designs. UML became the standard about a year later, so a revised version of the book was published in 1999 as “Fundamentals of Object-Oriented Design in UML”. Weirich says that the third part of the book, in which Page-Jones introduces the concept of connascence “is worth the price of the entire book”. (The price of the entire book, by the way, is not much – I just bought a used copy on Amazon for $1.36, so that was a pretty low-risk investment. I’m looking forward to getting the book and learning about connascence from the original source.) Meanwhile, here’s my summary of Weirich’s summary of Page-Jones writings about connascence: The stronger the form of connascence, the more difficult and costly it is to change the elements in the relationship. Some of the connascence types, ordered from weak to strong are: Connascence of Name Connascence of name is when multiple components must agree on the name of an entity. If you change the name of a method or property, then you need to change all references to that method or property. Duh. Connascence of name is unavoidable, assuming your objects are actually used. My main takeaway about connascence of name is that it emphasizes the importance of giving things good names so you don’t need to go changing them later. Connascence of Type Connascence of type is when multiple components must agree on the type of an entity. I assume this is more of a problem for languages without compilers (especially when used in apps without tests). I know it’s an issue with evil JavaScript type coercion. Connascence of Meaning Connascence of meaning is when multiple components must agree on the meaning of particular values, e.g that “1” means normal customer and “2” means preferred customer. The solution to this is to use constants or enums instead of “magic” strings or numbers, which reduces the coupling by changing the connascence form from “meaning” to “name”. Connascence of Position Connascence of positions is when multiple components must agree on the order of values. This refers to methods with multiple parameters, e.g.: eMailer.Send("[email protected]", "[email protected]", "Your order is complete", "Order completion notification"); The more parameters there are, the stronger the connascence of position is between the component and its callers. In the example above, it’s not immediately clear when reading the code which email addresses are sender and receiver, and which of the final two strings are subject vs. body. Connascence of position could be improved to connascence of type by replacing the parameter list with a struct or class. This “introduce parameter object” refactoring might be overkill for a method with 2 parameters, but would definitely be an improvement for a method with 10 parameters. This points out two “rules” of connascence:  The Rule of Degree: The acceptability of connascence is related to the degree of its occurrence. The Rule of Locality: Stronger forms of connascence are more acceptable if the elements involved are closely related. For example, positional arguments in private methods are less problematic than in public methods. Connascence of Algorithm Connascence of algorithm is when multiple components must agree on a particular algorithm. Be DRY – Don’t Repeat Yourself. If you have “cloned” code in multiple locations, refactor it into a common function.   Those are the “static” forms of connascence. There are also “dynamic” forms, including… Connascence of Execution Connascence of execution is when the order of execution of multiple components is important. Consumers of your class shouldn’t have to know that they have to call an .Initialize method before it’s safe to call a .DoSomething method. Connascence of Timing Connascence of timing is when the timing of the execution of multiple components is important. I’ll have to read up on this one when I get the book, but assume it’s largely about threading. Connascence of Identity Connascence of identity is when multiple components must reference the entity. The example Weirich gives is when you have two instances of the “Bob” Employee class and you call the .RaiseSalary method on one and then the .Pay method on the other does the payment use the updated salary?   Again, this is my summary of a summary, so please be forgiving if I misunderstood anything. Once I get/read the book, I’ll make corrections if necessary and share any other useful information I might learn.   See Also: Gregory Brown: Ruby Best Practices Issue #24: Connascence as a Software Design Metric (That link is failing at the time I write this, so I had to go to the Google cache of the page.)

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• An Alphabet of Eponymous Aphorisms, Programming Paradigms, Software Sayings, Annoying Alliteration

  - by Brian Schroer

  Malcolm Anderson blogged about “Einstein’s Razor” yesterday, which reminded me of my favorite software development “law”, the name of which I can never remember. It took much Wikipedia-ing to find it (Hofstadter’s Law – see below), but along the way I compiled the following list: Amara’s Law: We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run. Brook’s Law: Adding manpower to a late software project makes it later. Clarke’s Third Law: Any sufficiently advanced technology is indistinguishable from magic. Law of Demeter: Each unit should only talk to its friends; don't talk to strangers. Einstein’s Razor: “Make things as simple as possible, but not simpler” is the popular paraphrase, but what he actually said was “It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience”, an overly complicated quote which is an obvious violation of Einstein’s Razor. (You can tell by looking at a picture of Einstein that the dude was hardly an expert on razors or other grooming apparati.) Finagle's Law of Dynamic Negatives: Anything that can go wrong, will—at the worst possible moment. - O'Toole's Corollary: The perversity of the Universe tends towards a maximum. Greenspun's Tenth Rule: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. (Morris’s Corollary: “…including Common Lisp”) Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law. Issawi’s Omelet Analogy: One cannot make an omelet without breaking eggs - but it is amazing how many eggs one can break without making a decent omelet. Jackson’s Rules of Optimization: Rule 1: Don't do it. Rule 2 (for experts only): Don't do it yet. Kaner’s Caveat: A program which perfectly meets a lousy specification is a lousy program. Liskov Substitution Principle (paraphrased): Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it Mason’s Maxim: Since human beings themselves are not fully debugged yet, there will be bugs in your code no matter what you do. Nils-Peter Nelson’s Nil I/O Rule: The fastest I/O is no I/O.    Occam's Razor: The simplest explanation is usually the correct one. Parkinson’s Law: Work expands so as to fill the time available for its completion. Quentin Tarantino’s Pie Principle: “…you want to go home have a drink and go and eat pie and talk about it.” (OK, he was talking about movies, not software, but I couldn’t find a “Q” quote about software. And wouldn’t it be cool to write a program so great that the users want to eat pie and talk about it?) Raymond’s Rule: Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter.  Sowa's Law of Standards: Whenever a major organization develops a new system as an official standard for X, the primary result is the widespread adoption of some simpler system as a de facto standard for X. Turing’s Tenet: We shall do a much better programming job, provided we approach the task with a full appreciation of its tremendous difficulty, provided that we respect the intrinsic limitations of the human mind and approach the task as very humble programmers.  Udi Dahan’s Race Condition Rule: If you think you have a race condition, you don’t understand the domain well enough. These rules didn’t exist in the age of paper, there is no reason for them to exist in the age of computers. When you have race conditions, go back to the business and find out actual rules. Van Vleck’s Kvetching: We know about as much about software quality problems as they knew about the Black Plague in the 1600s. We've seen the victims' agonies and helped burn the corpses. We don't know what causes it; we don't really know if there is only one disease. We just suffer -- and keep pouring our sewage into our water supply. Wheeler’s Law: All problems in computer science can be solved by another level of indirection... Except for the problem of too many layers of indirection. Wheeler also said “Compatibility means deliberately repeating other people's mistakes.”. The Wrong Road Rule of Mr. X (anonymous): No matter how far down the wrong road you've gone, turn back. Yourdon’s Rule of Two Feet: If you think your management doesn't know what it's doing or that your organisation turns out low-quality software crap that embarrasses you, then leave. Zawinski's Law of Software Envelopment: Every program attempts to expand until it can read mail. Zawinski is also responsible for “Some people, when confronted with a problem, think 'I know, I'll use regular expressions.' Now they have two problems.” He once commented about X Windows widget toolkits: “Using these toolkits is like trying to make a bookshelf out of mashed potatoes.”

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• C# 4.0: Covariance And Contravariance In Generics

  - by Paulo Morgado

  C# 4.0 (and .NET 4.0) introduced covariance and contravariance to generic interfaces and delegates. But what is this variance thing? According to Wikipedia, in multilinear algebra and tensor analysis, covariance and contravariance describe how the quantitative description of certain geometrical or physical entities changes when passing from one coordinate system to another.(*) But what does this have to do with C# or .NET? In type theory, a the type T is greater (>) than type S if S is a subtype (derives from) T, which means that there is a quantitative description for types in a type hierarchy. So, how does covariance and contravariance apply to C# (and .NET) generic types? In C# (and .NET), variance applies to generic type parameters and not to the resulting generic type. A generic type parameter is: covariant if the ordering of the generic types follows the ordering of the generic type parameters: Generic<T> = Generic<S> for T = S. contravariant if the ordering of the generic types is reversed from the ordering of the generic type parameters: Generic<T> = Generic<S> for T = S. invariant if neither of the above apply. If this definition is applied to arrays, we can see that arrays have always been covariant because this is valid code: object[] objectArray = new string[] { "string 1", "string 2" }; objectArray[0] = "string 3"; objectArray[1] = new object(); However, when we try to run this code, the second assignment will throw an ArrayTypeMismatchException. Although the compiler was fooled into thinking this was valid code because an object is being assigned to an element of an array of object, at run time, there is always a type check to guarantee that the runtime type of the definition of the elements of the array is greater or equal to the instance being assigned to the element. In the above example, because the runtime type of the array is array of string, the first assignment of array elements is valid because string = string and the second is invalid because string = object. This leads to the conclusion that, although arrays have always been covariant, they are not safely covariant – code that compiles is not guaranteed to run without errors. In C#, the way to define that a generic type parameter as covariant is using the out generic modifier: public interface IEnumerable<out T> { IEnumerator<T> GetEnumerator(); } public interface IEnumerator<out T> { T Current { get; } bool MoveNext(); } Notice the convenient use the pre-existing out keyword. Besides the benefit of not having to remember a new hypothetic covariant keyword, out is easier to remember because it defines that the generic type parameter can only appear in output positions — read-only properties and method return values. In a similar way, the way to define a type parameter as contravariant is using the in generic modifier: public interface IComparer<in T> { int Compare(T x, T y); } Once again, the use of the pre-existing in keyword makes it easier to remember that the generic type parameter can only be used in input positions — write-only properties and method non ref and non out parameters. Because covariance and contravariance apply only to the generic type parameters, a generic type definition can have both covariant and contravariant generic type parameters in its definition: public delegate TResult Func<in T, out TResult>(T arg); A generic type parameter that is not marked covariant (out) or contravariant (in) is invariant. All the types in the .NET Framework where variance could be applied to its generic type parameters have been modified to take advantage of this new feature. In summary, the rules for variance in C# (and .NET) are: Variance in type parameters are restricted to generic interface and generic delegate types. A generic interface or generic delegate type can have both covariant and contravariant type parameters. Variance applies only to reference types; if you specify a value type for a variant type parameter, that type parameter is invariant for the resulting constructed type. Variance does not apply to delegate combination. That is, given two delegates of types Action<Derived> and Action<Base>, you cannot combine the second delegate with the first although the result would be type safe. Variance allows the second delegate to be assigned to a variable of type Action<Derived>, but delegates can combine only if their types match exactly. If you want to learn more about variance in C# (and .NET), you can always read: Covariance and Contravariance in Generics — MSDN Library Exact rules for variance validity — Eric Lippert Events get a little overhaul in C# 4, Afterward: Effective Events — Chris Burrows Note: Because variance is a feature of .NET 4.0 and not only of C# 4.0, all this also applies to Visual Basic 10.

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• SQLAuthority News – #TechEdIn – TechEd India 2012 Memories and Photos

  - by pinaldave

  TechEd India 2012 was held in Bangalore last March 21 to 23, 2012. Just like every year, this event is bigger, grander and inspiring. Pinal Dave at TechEd India 2012 Family Event Every single year, TechEd is a special affair for my entire family.  Four months before the start of TechEd, I usually start to build the mental image of the event. I start to think  about various things. For the most part, what excites me most is presenting a session and meeting friends. Seriously, I start thinking about presenting my session 4 months earlier than the event!  I work on my presentation day and night. I want to make sure that what I present is accurate and that I have experienced it firsthand. My wife and my daughter also contribute to my efforts. For us, TechEd is a family event, and the two of them feel equally responsible as well. They give up their family time so I can bring out the best content for the Community. Pinal, Shaivi and Nupur at TechEd India 2012 Guinea Pigs (My Experiment Victims) I do not rehearse my session, ever. However, I test my demo almost every single day till the last moment that I have to present it already. I sometimes go over the demo more than 2-3 times a day even though the event is more than a month away. I have two “guinea pigs”: 1) Nupur Dave and 2) Vinod Kumar. When I am at home, I present my demos to my wife Nupur. At times I feel that people often backup their demo, but in my case, I have backup demo presenters. In the office during lunch time, I present the demos to Vinod. I am sure he can walk my demos easily with eyes closed. Pinal and Vinod at TechEd India 2012 My Sessions I’ve been determined to present my sessions in a real and practical manner. I prefer to present the subject that I myself would be eager to attend to and sit through if I were an audience. Just keeping that principle in mind, I have created two sessions this year. SQL Server Misconception and Resolution Pinal and Vinod at TechEd India 2012 We believe all kinds of stuff – that the earth is flat, or that the forbidden fruit is apple, or that the big bang theory explains the origin of the universe, and so many other things. Just like these, we have plenty of misconceptions in SQL Server as well. I have had this dream of co-presenting a session with Vinod Kumar for the past 3 years. I have been asking him every year if we could present a session together, but we never got it to work out, until this year came. Fortunately, we got a chance to stand on the same stage and present a single subject.  I believe that Vinod Kumar and I have an excellent synergy when we are working together. We know each other’s strengths and weakness. We know when the other person will speak and when he will keep quiet. The reason behind this synergy is that we have worked on 2 Video Learning Courses (SQL Server Indexes and SQL Server Questions and Answers) and authored 1 book (SQL Server Questions and Answers) together. Crowd Outside Session Hall This session was inspired from the “Laurel and Hardy” show so we performed a role-playing of those famous characters. We had an excellent time at the stage and, for sure, the audience had a wonderful time, too. We had an extremely large audience for this session and had a great time interacting with them. Speed Up! – Parallel Processes and Unparalleled Performance Pinal Dave at TechEd India 2012 I wanted to approach this session at level 400 and I was very determined to do so. The biggest challenge I had was that this was a total of 60 minutes of session and the audience profile was very generic. I had to present at level 100 as well at 400. I worked hard to tune up these demos. I wanted to make sure that my messages would land perfectly to the minds of the attendees, and when they walk out of the session, they could use the knowledge I shared on their servers. After the session, I felt an extreme satisfaction as I received lots of positive feedback at the event. At one point, so many people rushed towards me that I was a bit scared that the stage might break and someone would get injured. Fortunately, nothing like that happened and I was able to shake hands with everybody. Pinal Dave at TechEd India 2012 Crowd rushing to Pinal at TechEd India 2012 Networking This is one of the primary reasons many of us visit the annual TechEd event. I had a fantastic time meeting SQL Server enthusiasts. Well, it was a terrific time meeting old friends, user group members, MVPs and SQL Enthusiasts. I have taken many photographs with lots of people, but I have received a very few back. If you are reading this blog and have a photo of us at the event, would you please send it to me so I could keep it in my memory lane? SQL Track Speaker: Jacob and Pinal at TechEd India 2012 SQL Community: Pinal, Tejas, Nakul, Jacob, Balmukund, Manas, Sudeepta, Sahal at TechEd India 2012 Star Speakers: Amit and Balmukund at TechEd India 2012 TechED Rockstars: Nakul, Tejas and Pinal at TechEd India 2012 I guess TechEd is a mix of family affair and culture for me! Hamara TechEd (Our TechEd) Please tell me which photo you like the most! Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, SQLServer, T SQL, Technology Tagged: TechEd, TechEdIn

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• The illusion of Competence

  - by tony_lombardo

  Working as a contractor opened my eyes to the developer food chain.  Even though I had similar experiences earlier in my career, the challenges seemed much more vivid this time through.  I thought I’d share a couple of experiences with you, and the lessons that can be taken from them. Lesson 1: Beware of the “funnel” guy.  The funnel guy is the one who wants you to funnel all thoughts, ideas and code changes through him.  He may say it’s because he wants to avoid conflicts in source control, but the real reason is likely that he wants to hide your contributions.  Here’s an example.  When I finally got access to the code on one of my projects, I was told by the developer that I had to funnel all of my changes through him.  There were 4 of us coding on the project, but only 2 of us working on the UI.  The other 2 were working on a separate application, but part of the overall project.  So I figured, I’ll check it into SVN, he reviews and accepts then merges in.  Not even close.  I didn’t even have checkin rights to SVN, I had to email my changes to the developer so he could check those changes in.  Lesson 2: If you point out flaws in code to someone supposedly ‘higher’ than you in the developer chain, they’re going to get defensive.  My first task on this project was to review the code, familiarize myself with it.  So of course, that’s what I did.  And in familiarizing myself with it, I saw so many bad practices and code smells that I immediately started coming up with solutions to fix it.  Of course, when I reviewed these changes with the developer (guy who originally wrote the code), he smiled and nodded and said, we can’t make those changes now, it’s too destabilizing.  I recommended we create a new branch and start working on refactoring, but branching was a new concept for this guy and he was worried we would somehow break SVN. How about some concrete examples? I started out by recommending we remove NUnit dependency and tests from the application project, and create a separate Unit testing project.  This was met with a little bit of resistance because - “How do I access the private methods?”  As it turned out there weren’t really any private methods that weren’t exposed by public methods, so I quickly calmed this fear. Win 1 Loss 0 Next, I recommended that all of the File IO access be wrapped in Using clauses, or at least properly wrapped in try catch finally.  This recommendation was accepted.. but never implemented. Win 2  Loss 1 Next recommendation was to refactor the command pattern implementation.  The command pattern was implemented, but it wasn’t really necessary for the application.  More over, the fact that we had 100 different command classes, each with it’s own specific command parameters class, made maintenance a huge hassle.  The same code repeated over and over and over.  This recommendation was declined, the code was too fragile and this change would destabilize it.  I couldn’t disagree, though it was the commands themselves in many cases that were fragile. Win 2 Loss 2 Next recommendation was to aid performance (and responsiveness) of the application by using asynchronous service calls.  This on was accepted. Win 2 Loss 3 If you’re paying any attention, you’re wondering why the async service calls was scored as a loss.. Let me explain.  The service call was made using the async pattern.  Followed by a thread.sleep  <facepalm>. Now it’s easy to be harsh on this kind of code, especially if you’re an experienced developer.  But I understood how most of this happened.  One junior guy, working as hard as he can to build his first real world application, with little or no guidance from anyone else.  He had his pattern book and theory of programming to help him, but no real world experience.  He didn’t know how difficult it would be to trace the crashes to the coding issues above, but he will one day.  The part that amazed me was the management position that “this guy should be a team lead, because he’s worked so hard”.  I’m all for rewarding hard work, but when you reward someone by promoting them past the point of their competence, you’re setting yourself and them up for failure.  And that’s lesson 3.  Just because you’ve got a hard worker, doesn’t mean he should be leading a development project.  If you’re a junior guy busting your ass, keep at it.  I encourage you to try new things, but most importantly to learn from your mistakes.  And correct your mistakes.  And if someone else looks at your code and shows you a laundry list of things that should be done differently, don’t take it personally – they’re really trying to help you.  And if you’re a senior guy, working with a junior guy, it’s your duty to point out the flaws in the code.  Even if it does make you the bad guy.  And while I’ve used “guy” above, I mean both men and women.  And in some cases mutant dinosaurs. 

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• College Courses through distance learning

  - by Matt

  I realize this isn't really a programming question, but didn't really know where to post this in the stackexchange and because I am a computer science major i thought id ask here. This is pretty unique to the programmer community since my degree is about 95% programming. I have 1 semester left, but i work full time. I would like to finish up in December, but to make things easier i like to take online classes whenever I can. So, my question is does anyone know of any colleges that offer distance learning courses for computer science? I have been searching around and found a few potential classes, but not sure yet. I would like to gather some classes and see what i can get approval for. Class I need: Only need one C SC 437 Geometric Algorithms C SC 445 Algorithms C SC 473 Automata Only need one C SC 452 Operating Systems C SC 453 Compilers/Systems Software While i only need of each of the above courses i still need to take two more electives. These also have to be upper 400 level classes. So i can take multiple in each category. Some other classes I can take are: CSC 447 - Green Computing CSC 425 - Computer Networking CSC 460 - Database Design CSC 466 - Computer Security I hoping to take one or two of these courses over the summer. If not, then online over the regular semester would be ok too. Any help in helping find these classes would be awesome. Maybe you went to a college that offered distance learning. Some of these classes may be considered to be graduate courses too. Descriptions are listed below if you need. Thanks! Descriptions Computer Security This is an introductory course covering the fundamentals of computer security. In particular, the course will cover basic concepts of computer security such as threat models and security policies, and will show how these concepts apply to specific areas such as communication security, software security, operating systems security, network security, web security, and hardware-based security. Computer Networking Theory and practice of computer networks, emphasizing the principles underlying the design of network software and the role of the communications system in distributed computing. Topics include routing, flow and congestion control, end-to-end protocols, and multicast. Database Design Functions of a database system. Data modeling and logical database design. Query languages and query optimization. Efficient data storage and access. Database access through standalone and web applications. Green Computing This course covers fundamental principles of energy management faced by designers of hardware, operating systems, and data centers. We will explore basic energy management option in individual components such as CPUs, network interfaces, hard drives, memory. We will further present the energy management policies at the operating system level that consider performance vs. energy saving tradeoffs. Finally we will consider large scale data centers where energy management is done at multiple layers from individual components in the system to shutting down entries subset of machines. We will also discuss energy generation and delivery and well as cooling issues in large data centers. Compilers/Systems Software Basic concepts of compilation and related systems software. Topics include lexical analysis, parsing, semantic analysis, code generation; assemblers, loaders, linkers; debuggers. Operating Systems Concepts of modern operating systems; concurrent processes; process synchronization and communication; resource allocation; kernels; deadlock; memory management; file systems. Algorithms Introduction to the design and analysis of algorithms: basic analysis techniques (asymptotics, sums, recurrences); basic design techniques (divide and conquer, dynamic programming, greedy, amortization); acquiring an algorithm repertoire (sorting, median finding, strong components, spanning trees, shortest paths, maximum flow, string matching); and handling intractability (approximation algorithms, branch and bound). Automata Introduction to models of computation (finite automata, pushdown automata, Turing machines), representations of languages (regular expressions, context-free grammars), and the basic hierarchy of languages (regular, context-free, decidable, and undecidable languages). Geometric Algorithms The study of algorithms for geometric objects, using a computational geometry approach, with an emphasis on applications for graphics, VLSI, GIS, robotics, and sensor networks. Topics may include the representation and overlaying of maps, finding nearest neighbors, solving linear programming problems, and searching geometric databases.

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• Java2Days 2012 Trip Report

  - by reza_rahman

  Java2Days 2012 was held in beautiful Sofia, Bulgaria on October 25-26. For those of you not familiar with it, this is the third installment of the premier Java conference for the Balkan region. It is an excellent effort by admirable husband and wife team Emo Abadjiev and Iva Abadjieva as well as the rest of the Java2Days team including Yoana Ivanova and Nadia Kostova. Thanks to their hard work, the conference continues to grow vigorously with almost a thousand enthusiastic, bright young people attending this year and no less than three tracks on Java, the Cloud and Mobile. The conference is a true gem in this region of the world and I am very proud to have been a part of it again, along with the other world class speakers the event rightfully attracts. It was my honor to present the first talk of the conference. It was a full-house session on Java EE 7 and 8 titled "JavaEE.Next(): Java EE 7, 8, and Beyond". The talk was primarily along the same lines as Arun Gupta's JavaOne 2012 technical keynote. I covered the changes in JMS 2, the Java API for WebSocket (JSR 356), the Java API for JSON Processing (JSON-P), JAX-RS 2, JCache, JPA 2.1, JTA 1.2, JSF 2.2, Java Batch, Bean Validation 1.1 and the rest of the APIs in Java EE 7. I also briefly talked about the possible contents of Java EE 8. My stretch goal was to gather some feedback on some open issues in the Java EE EG (more on that soon) but I ran out of time in the short format forty-five minute session. The talk was received well and I had some pretty good discussions afterwards. The slides for the talk are here: JavaEE.Next(): Java EE 7, 8, and Beyond from reza_rahman To my delight, the Java2Days folks were very interested in my domain-driven design/Java EE 6 talk (titled "Domain Driven Design with Java EE 6"). I've had this talk in my inventory for a long time now but it always gets overridden by less theoretical talks on APIs, tools, etc. The talk has three parts -- a brief overview of DDD theory, mapping DDD to Java EE and actual running DDD code in Java EE 6/GlassFish. For the demo, I converted the well-known DDD sample application (http://dddsample.sourceforge.net/) written mostly in Spring 2 and Hibernate 2 to Java EE 6. My eventual plan is to make the code available via a top level java.net project. Even despite the broad topic and time constraints, the talk went very well. It was a full house, the Q & A was excellent and one of the other speakers even told me they thought this was the best talk of the conference! The slides for the talk are here: Domain Driven Design with Java EE 6 from Reza Rahman The code examples are available here: https://blogs.oracle.com/reza/resource/dddsample.zip for now, as a simple zip file. Give me a shout if you would like to get it up and running. It was also a great honor to present the last session of the conference. It was a talk on the Java API for WebSocket/JSR 356 titled "Building HTML5/WebSocket Applications with JSR 356 and GlassFish". The talk is based on Danny Coward's JavaOne 2012 talk. The talk covers the basic of WebSocket, the JSR 356 API and a simple demo using Tyrus/GlassFish. The talk went very well and there were some very good questions afterwards. The slides for the talk are here: Building HTML5/WebSocket Applications with GlassFish and JSR 356 from Reza Rahman The code samples are available here: https://blogs.oracle.com/arungupta/resource/totd183-HelloWebSocket.zip. You'll need the latest promoted GlassFish 4 build to run the code. Give me a shout if you need help. Besides presenting my talks, I got to attend some great sessions on OSGi, HTML5, cloud, agile and Java 8. I got an invite to speak at the Macedonia JUG when possible. Victor Grazi of InfoQ wrote about my sessions and Java2Days here: http://www.infoq.com/news/2012/11/Java2DaysConference. Stoyan Rachev was very kind to blog about my sessions here: http://www.stoyanr.com/2012/11/java2days-2012-java-ee.html. I definitely enjoyed Java2Days 2012 and hope to be part of the conference next year!

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• Must-see sessions at TCUK11

  - by Roger Hart

  Technical Communication UK is probably the best professional conference I've been to. Last year, I spoke there on content strategy, and this year I'll be co-hosting a workshop on embedded user assistance. Obviously, I'd love people to come along to that; but there are some other sessions I'd like to flag up for anybody thinking of attending. Tuesday 20th Sept - workshops This will be my first year at the pre-conference workshop day, and I'm massively glad that our workshop hasn't been scheduled along-side the one I'm really interested in. My picks: It looks like you're embedding user assistance. Would you like help? My colleague Dom and I are presenting this one. It's our paen to Clippy, to the brilliant idea he represented, and the crashing failure he was. Less precociously, we'll be teaching embedded user assistance, Red Gate style. Statistics without maths: acquiring, visualising and interpreting your data This doesn't need to do anything apart from what it says on the tin in order to be gold dust. But given the speakers, I suspect it will. A data-informed approach is a great asset to technical communications, so I'd recommend this session to anybody event faintly interested. The speakers here have a great track record of giving practical, accessible introductions to big topics. Go along. Wednesday 21st Sept - day one There's no real need to recommend the keynote for a conference, but I will just point out that this year it's Google's Patrick Hofmann. That's cool. You know what else is cool: Focus on the user, the rest follows An intro to modelling customer experience. This is a really exciting area for tech comms, and potentially touches on one of my personal hobby-horses: the convergence of technical communication and marketing. It's all part of delivering customer experience, and knowing what your users need lets you help them, sell to them, and delight them. Content strategy year 1: a tale from the trenches It's often been observed that content strategy is great at banging its own drum, but not so hot on compelling case studies. Here you go, folks. This is the presentation I'm most excited about so far. On a mission to communicate! Skype help their users communicate, but how do they communicate with them? I guess we'll find out. Then there's the stuff that I'm not too excited by, but you might just be. The standards geeks and agile freaks can get together in a presentation on the forthcoming ISO standards for agile authoring. Plus, there's a session on VBA for tech comms. I do have one gripe about day 1. The other big UK tech comms conference, UA Europe, have - I think - netted the more interesting presentation from Ellis Pratt. While I have no doubt that his TCUK case study on producing risk assessments will be useful, I'd far rather go to his talk on game theory for tech comms. Hopefully UA Europe will record it. Thursday 22nd Sept - day two Day two has a couple of slots yet to be confirmed. The rumour is that one of them will be the brilliant "Questions and rants" session from last year. I hope so. It's not ranting, but I'll be going to: RTFMobile: beyond stating the obvious Ultan O'Broin is an engaging speaker with a lot to say, and mobile is one of the most interesting and challenging new areas for tech comms. Even if this weren't a research-based presentation from a company with buckets of technology experience, I'd be going. It is, and you should too. Pattern recognition for technical communicators One of the best things about TCUK is the tendency to include sessions that tackle the theoretical and bring them towards the practical. Kai and Chris delivered cracking and well-received talks last year, and I'm looking forward to seeing what they've got for us on some of the conceptual underpinning of technical communication. Developing an interactive non-text learning programme Annoyingly, this clashes with Pattern Recognition, so I hope at least one of the streams is recorded again this year. The idea of communicating complex information without words us fascinating and this sounds like a great example of this year's third stream: "anything but text". For the localization and DITA crowds, there's rich pickings on day two, though I'm not sure how many of those sessions I'm interested in. In the 13:00 - 13:40 slot, there's an interesting clash between Linda Urban on re-use and training content, and a piece on minimalism I'm sorely tempted by. That's my pick of #TCUK11. I'll be doing a round-up blog after the event, and probably talking a bit more about it beforehand. I'm also reliably assured that there are still plenty of tickets.

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• Global Perspective: Oracle AppAdvantage Does its Stage Debut in the UK

  - by Tanu Sood

  Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Global Perspective is a monthly series that brings experiences, business needs and real-world use cases from regions across the globe. This month’s feature is a follow-up from last month’s Global Perspective note from a well known ACE Director based in EMEA. My first contribution to this blog was before Oracle Open World and I was quite excited about where this initiative would take me in my understanding of the value of Oracle Fusion Middleware. Rimi Bewtra from the Oracle AppAdvantage team came as promised to the Oracle ACE Director briefings and explained what this initiative was all about and I then asked the directors to take part in the new survey. The story was really well received and then at the SOA advisory board that many of these ACE Directors already take part in there was a further discussion on how this initiative will help customers understand the benefits of adoption. A few days later Rick Beers launched the program at a lunch of invited customer executives which included one from Pella who talked about their projects (a quick recap on that here). I wasn’t able to stay for the whole event but what really interested me was that these executives who understood the technology but where looking for how they could use them to drive their businesses. Lots of ideas were bubbling up in my head about how we can use this in user groups to help our members, and the timing was fantastic as just three weeks later we had UKOUG_Apps13, our flagship Applications conference in the UK. We had independently working with Oracle marketing in the UK on an initiative called Apps Transformation to help our members look beyond just the application they use today. We have had a Fusion community page but felt the options open are now much wider than Fusion Applications, there are acquired applications, social, mobility and of course the underlying technology, Oracle Fusion Middleware. I was really pleased to be allowed to give the Oracle AppAdvantage story as a session in our conference and we are planning a special Apps Transformation event in March where I hope the Oracle AppAdvantage team will take part and we will have the results of the survey to discuss. But, life also came full circle for me. In my first post, I talked about Andrew Sutherland and his original theory that Oracle Fusion Middleware adoption had technical drivers. Well, Andrew was a speaker at our event and he gave a potted, tech-talk free update on Oracle Open World. Andrew talked about the Prevailing Technology Winds, and what is driving this today and he talked about that in the past it was the move from simply automating processes (ERP etc), through the altering of those processes (SOA) and onto consolidation. The next drivers are around the need to predict, both faster and more accurately; how to better exploit the information that we have available. He went on to talk about The Nexus of Forces: Social, Mobile, Cloud and Information – harnessing these forces of change with Oracle technology. Gartner really likes this concept and if you want to know more you can get their paper here. All this has made me think, and I hope it will make you too. Technology can help us drive our businesses better and understanding your needs can be the first step on your journey, which was the theme of our event in the UK. I spoke to a number of the delegates and I hope to share some of their stories in later posts. If you have a story to share, the survey is at: https://www.surveymonkey.com/s/P335DD3 About the Author: Debra Lilley, Fujitsu Fusion Champion, UKOUG Board Member, Fusion User Experience Advocate and ACE Director. Debra has 18 years experience with Oracle Applications, with E Business Suite since 9.4.1, moving to Business Intelligence Team Leader and then Oracle Alliance Director. She has spoken at over 100 conferences worldwide and posts at debrasoraclethoughts Editor’s Note: Debra has kindly agreed to share her musings and experience in a monthly column on the Fusion Middleware blog so do stay tuned…

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• Updating a database connection password using a script

  - by Tim Dexter

  An interesting customer requirement that I thought was worthy of sharing today. Thanks to James for the requirement and Bryan for the proposed solution and me for testing the solution and proving it works :0) A customers implementation of Sarbanes Oxley requires them to change all database account passwords every 90 days. This is scripted leveraging shell scripts today for most of their environments. But how can they manage the BI Publisher connections? Now, the customer is running 11g and therefore using weblogic on the middle tier, which is the first clue to Bryans proposed solution. To paraphrase and embellish Bryan's solution a little; why not use a JNDI connection from BIP to the database. Then employ the web logic scripting engine to make updates to the JNDI as needed? BIP is completely uninvolved and with a little 'timing' users will be completely unaware of the password updates i.e. change the password when reports are not being executed. Perfect! James immediately tracked down the WLST script that could be used here, http://middlewaremagic.com/weblogic/?p=4261 (thanks Ravish) Now it was just a case of testing the theory. Some steps: Create the JNDI connection in WLS Create the JNDI connection in BI Publisher pointing to the WLS connection Build new data models using or re-point data sources to use the JNDI connection. Create the WLST script to update the WLS JNDI password as needed. Test! Some details. Creating the JNDI connection in web logic is pretty straightforward. Log into hte console and look for Data Sources under the Services section of the home page and click it Click New >> Generic Datasource Give the connection a name. For the JNDI name, prefix it with 'jdbc/' so I have 'jdbc/localdb' - this name is important you'll need it on the BIP side. Select your db type - this will influence the drivers and information needed on the next page. Being a company man, Im using an Oracle db. Click Next Select the driver of choice, theres lots I know, you can read about them I just chose 'Oracle's Driver (Thin) for Instance connections; Versions 9.0.1 and later' Click Next >> Next Fill out the db name (SID), server, port, username to connect and password >> Next Test the config to ensure you can connect. >> Next Now you need to deploy the connection to your BI server, select it and click Next. You're done with the JNDI config. Creating the JNDI connection on the Publisher side is covered here. Just remember to the connection name you created in WLS e.g. 'jdbc/localdb' Not gonna tell you how to do this, go read the user guide :0) Suffice to say, it works. This requires a little reading around the subject to understand the scripting engine and how to execute scripts. Nicely covered here. However a bit of googlin' and I found an even easier way of running the script. ${ServerHome}/common/bin/wlst.sh updatepwd.py Where updatepwd.py is my script file, it can be in another directory. As part of the wlst.sh script your environment is set up for you so its very simple to execute. The nitty gritty: Need to take Ravish's script above and create a file with a .py extension. Its going to need some modification, as he explains on the web page, to make it work in your environment. I played around with it for a while but kept running into errors. The script as is, tries to loop through all of your connections and modify the user and passwords for each. Not quite what we are looking for. Remember our requirement is to just update the password for a given connection. I also found another issue with the script. WLS 10.x does not allow updates to passwords using clear type ie un-encrypted text while the server is in production mode. Its a bit much to set it back to developer mode bounce it, change the passwords and then bounce and then change back to production and bounce again. After lots of messing about I finally came up with the following: ############################################################################# # # Update password for JNDI connections # ############################################################################# print("*** Trying to Connect.... *****") connect('weblogic','welcome1','t3://localhost:7001') print("*** Connected *****") edit() startEdit() print ("*** Encrypt the password ***") en = encrypt('hr') print "Encrypted pwd: ", en print ("*** Changing pwd for LocalDB ***") dsName = 'LocalDB' print 'Changing Password for DataSource ', dsName cd('/JDBCSystemResources/'+dsName+'/JDBCResource/'+dsName+'/JDBCDriverParams/'+dsName) set('PasswordEncrypted',en) save() activate() Its pretty simple and you can expand on it to loop through the data sources and change each as needed. I have hardcoded the password into the file but you can pass it as a parameter as needed using the properties file method. Im not going to get into the detail of that here but its covered with an example here. Couple of points to note: 1. The change to the password requires a server bounce to get the changes picked up. You can add that to the shell script you will use to call the script above. 2. The script above needs to be run from the MW_HOME\user_projects\domains\bifoundation_domain directory to get the encryption libraries set correctly. My command to run the whole script was: d:\oracle\bi_mw\wlserver_10.3\common\bin\wlst.cmd updatepwd.py - where wlst.cmd is the scripting command line and updatepwd.py was my update password script above. I have not quite spoon fed everything you need to make it a robust script but at least you know you can do it and you can work out the rest I think :0)

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• SQL SERVER – ?Finding Out What Changed in a Deleted Database – Notes from the Field #041

  - by Pinal Dave

  [Note from Pinal]: This is a 41th episode of Notes from the Field series. The real world is full of challenges. When we are reading theory or book, we sometimes do not realize how real world reacts works and that is why we have the series notes from the field, which is extremely popular with developers and DBA. Let us talk about interesting problem of how to figure out what has changed in the DELETED database. Well, you think I am just throwing the words but in reality this kind of problems are making our DBA’s life interesting and in this blog post we have amazing story from Brian Kelley about the same subject. In this episode of the Notes from the Field series database expert Brian Kelley explains a how to find out what has changed in deleted database. Read the experience of Brian in his own words. Sometimes, one of the hardest questions to answer is, “What changed?” A similar question is, “Did anything change other than what we expected to change?” The First Place to Check – Schema Changes History Report: Pinal has recently written on the Schema Changes History report and its requirement for the Default Trace to be enabled. This is always the first place I look when I am trying to answer these questions. There are a couple of obvious limitations with the Schema Changes History report. First, while it reports what changed, when it changed, and who changed it, other than the base DDL operation (CREATE, ALTER, DELETE), it does not present what the changes actually were. This is not something covered by the default trace. Second, the default trace has a fixed size. When it hits that size, the changes begin to overwrite. As a result, if you wait too long, especially on a busy database server, you may find your changes rolled off. But the Database Has Been Deleted! Pinal cited another issue, and that’s the inability to run the Schema Changes History report if the database has been dropped. Thankfully, all is not lost. One thing to remember is that the Schema Changes History report is ultimately driven by the Default Trace. As you may have guess, it’s a trace, like any other database trace. And the Default Trace does write to disk. The trace files are written to the defined LOG directory for that SQL Server instance and have a prefix of log_: Therefore, you can read the trace files like any other. Tip: Copy the files to a working directory. Otherwise, you may occasionally receive a file in use error. With the Default Trace files, if you ask the question early enough, you can see the information for a deleted database just the same as any other database. Testing with a Deleted Database: Here’s a short script that will create a database, create a schema, create an object, and then drop the database. Without the database, you can’t do a standard Schema Changes History report. CREATE DATABASE DeleteMe; GO USE DeleteMe; GO CREATE SCHEMA Test AUTHORIZATION dbo; GO CREATE TABLE Test.Foo (FooID INT); GO USE MASTER; GO DROP DATABASE DeleteMe; GO This sets up the perfect situation where we can’t retrieve the information using the Schema Changes History report but where it’s still available. Finding the Information: I’ve sorted the columns so I can see the Event Subclass, the Start Time, the Database Name, the Object Name, and the Object Type at the front, but otherwise, I’m just looking at the trace files using SQL Profiler. As you can see, the information is definitely there: Therefore, even in the case of a dropped/deleted database, you can still determine who did what and when. You can even determine who dropped the database (loginame is captured). The key is to get the default trace files in a timely manner in order to extract the information. If you want to get started with performance tuning and database security with the help of experts, read more over at Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, T SQL

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• What Counts For a DBA: Fitness

  - by Louis Davidson

  If you know me, you can probably guess that physical exercise is not really my thing. There was a time in my past when it a larger part of my life, but even then never in the same sort of passionate way as a number of our SQL friends.  For me, I find that mental exercise satisfies what I believe to be the same inner need that drives people to run farther than I like to drive on most Saturday mornings, and it is certainly just as addictive. Mental fitness shares many common traits with physical fitness, especially the need to attain it through repetitive training. I only wish that mental training burned off a bacon cheeseburger in the same manner as does jogging around a dewy park on Saturday morning. In physical training, there are at least two goals, the first of which is to be physically able to do a task. The second is to train the brain to perform the task without thinking too hard about it. No matter how long it has been since you last rode a bike, you will be almost certainly be able to hop on and start riding without thinking about the process of pedaling or balancing. If you’ve never ridden a bike, you could be a physics professor /Olympic athlete and still crash the first few times you try, even though you are as strong as an ox and your knowledge of the physics of bicycle riding makes the concept child’s play. For programming tasks, the process is very similar. As a DBA, you will come to know intuitively how to backup, optimize, and secure database systems. As a data programmer, you will work to instinctively use the clauses of Transact-SQL DML so that, when you need to group data three ways (and not four), you will know to use the GROUP BY clause with GROUPING SETS without resorting to a search engine.  You have the skill. Making it naturally then requires repetition and experience is the primary requirement, not just simply learning about a topic. The hardest part of being really good at something is this difference between knowledge and skill. I have recently taken several informative training classes with Kimball University on data warehousing and ETL. Now I have a lot more knowledge about designing data warehouses than before. I have also done a good bit of data warehouse designing of late and have started to improve to some level of proficiency with the theory. Yet, for all of this head knowledge, it is still a struggle to take what I have learned and apply it to the designs I am working on.  Data warehousing is still a task that is not yet deeply ingrained in my brain muscle memory. On the other hand, relational database design is something that no matter how much or how little I may get to do it, I am comfortable doing it. I have done it as a profession now for well over a decade, I teach classes on it, and I also have done (and continue to do) a lot of mental training beyond the work day. Sometimes the training is just basic education, some reading blogs and attending sessions at PASS events.  My best training comes from spending time working on other people’s design issues in forums (though not nearly as much as I would like to lately). Working through other people’s problems is a great way to exercise your brain on problems with which you’re not immediately familiar. The final bit of exercise I find useful for cultivating mental fitness for a data professional is also probably the nerdiest thing that I will ever suggest you do.  Akin to running in place, the idea is to work through designs in your head. I have designed more than one database system that would revolutionize grocery store operations, sales at my local Target store, the ordering process at Amazon, and ways to improve Disney World operations to get me through a line faster (some of which they are starting to implement without any of my help.) Never are the designs truly fleshed out, but enough to work through structures and processes.  On “paper”, I have designed database systems to catalog things as trivial as my Lego creations, rental car companies and my audio and video collections. Once I get the database designed mentally, sometimes I will create the database, add some data (often using Red-Gate’s Data Generator), and write a few queries to see if a concept was realistic, but I will rarely fully flesh out the database since I have no desire to do any user interface programming anymore.  The mental training allows me to keep in practice for when the time comes to do the work I love the most for real…even if I have been spending most of my work time lately building data warehouses.  If you are really strong of mind and body, perhaps you can mix a mental run with a physical run; though don’t run off of a cliff while contemplating how you might design a database to catalog the trees on a mountain…that would be contradictory to the purpose of both types of exercise.

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• Trouble with Samba Domain

  - by Arkevius

  I'm having a bit of trouble setting up this Samba domain correctly. I'm getting an Access Denied error when trying to add a Windows XP machine to the domain. I'll go through my scenario in detail, but for those of you wanting a TLDR summary it'll be at the bottom of this post. I have HP Proliant server with Ubuntu 12.04 LTS installed. For this particular environment, I need this server to act as a PDC, file server, and print server. I began by updating and upgrading the packages (of course). Then went to install samba, gnome-desktop, wine, and cpanm. Samba was, of course, for the PDC and file/print services. The GUI was needed because a certain software has to be installed on there that needs a GUI. Wine was needed because the software is Windows-native. And cpanm was for a perl script I have running. For Samba, I went into the smb.conf file and enabled domain logons, changed the workgroup/domain name, the logon script for a per-group basis (netlogon/%g), enabled the netlogon and profiles share, and setup a couple of custom shares for the file service. The printer was added later, and seems to be working just fine. I then restarted the services, and used the net groupmap command to ensure my unix groups were mapped correctly to the Windows groups. After this, I went to a Windows box, and was able to successfully join the domain without a problem. After some fidgeting with the software to get it running on the win boxes from the server (it's a records management system program, which stores it's database files on the server), I went to add another computer to the domain. But now it's saying Access Denied. Before when I had this trouble it was because I forgot to add the group "machines" so Samba could create machine accounts. Thinking this was the case, I manually created the machine account to test this theory. However, it would still give me an Access Denied error. That must mean it has something to do with permissions now, correct? I've been fighting with this server for the past two weeks. If it's not one thing that;s wrong, then it's something else completely different. This would be the third time I've actually reinstalled everything to start over. I'll post snippets of my system settings below. If anything else is needed, just say the word and I'll gather up the info. The unix group 'domadmin' is the Domain Admins group. Samba Administrator account administrator:x:1000:1000:Administrator,,,:/home/administrator:/bin/bash Adminstrator's groups administrator adm cdrom sudo dip plugdev lpadmin sambashare domadmin crimestar Samba's Configuration FIle (a snippet anyways) [global] workgroup = CITYPD server string = BPDServer dns proxy = no log file = /var/log/samba/log.%m max log size = 1000 syslog = 0 panic action = /usr/share/samba/panic-action %d security = user encrypt passwords = true passdb backend = tdbsam obey pam restrictions = yes unix password sync = yes passwd program = /usr/bin/passwd %u passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* . pam password change = yes map to guest = bad user domain logons = yes logon path = \\%L\srv\samba\profiles\%U logon script = logon.bat add machine script = /usr/sbin/useradd -g machines -c "%u machine account" -d /var/lib/samba -s /bin/false %u domain master = yes usershare allow guests = yes [netlogon] comment = Network Logon Service path = /srv/samba/netlogon/%g guest ok = yes read only = yes browseable = no [profiles] comment = All Printers browseable = no path = /var/spool/samba printable = yes guest ok = no read only = yes create mask = 0700 [print$] comment = Printer Drivers path = /var/lib/samba/printers browseable = yes read only = yes guest ok = no write list = root, @lpadmin [crimestar] comment = "Crimestar DB" path = /srv/crimestar/db valid users = @domadmin, @crimestar admin users = administrator writeable = yes guest ok = no browseable = no create mask = 0666 directory mask = 0777 [crimestarfiles] path = /home/administrator/.wine/drive_c/crimestar admin users = administrator browseable = yes ls -la on /srv/samba/profiles drwxrwxrwx 2 root machines 4096 Nov 21 15:27 . drwxr-xr-x 4 root root 4096 Nov 21 15:28 .. ls -la on /srv/samba/netlogon drwxr-xr-x 6 root root 4096 Nov 21 15:30 . drwxr-xr-x 4 root root 4096 Nov 21 15:28 .. drwxr-xr-x 2 root root 4096 Nov 21 15:30 crimestar drwxr-xr-x 2 root root 4096 Nov 21 18:13 domadmin drwxr-xr-x 3 root root 4096 Nov 21 15:30 guests drwxr-xr-x 2 root root 4096 Nov 21 15:29 users GrouMap list Domain Users (S-1-5-21-2978508755-2341913247-928297747-513) -> users Domain Admins (S-1-5-21-2978508755-2341913247-928297747-512) -> domadmin Domain Guests (S-1-5-21-2978508755-2341913247-928297747-514) -> nogroup TLDR I'm getting an Access Denied error message while trying to join a windows box to a samba domain, even after I successfully joined another computer without a problem. System settings / files are quoted above. Anyone have any ideas or suggestions?

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• WMemoryProfiler is Released

  - by Alois Kraus

  What is it? WMemoryProfiler is a managed profiling Api to aid integration testing. This free library can get managed heap statistics and memory usage for your own process (remember testing) and other processes as well. The best thing is that it does work from .NET 2.0 up to .NET 4.5 in x86 and x64. To make it more interesting it can attach to any running .NET process. The reason why I do mention this is that commercial profilers do support this functionality only for their professional editions. An normally only since .NET 4.0 since the profiling API only since then does support attaching to a running process. This thing does differ in many aspects from “normal” profilers because while profiling yourself you can get all objects from all managed heaps back as an object array. If you ever wanted to change the state of an object which does only exist a method local in another thread you can get your hands on it now … Enough theory. Show me some code /// <summary> /// Show feature to not only get statisics out of a process but also the newly allocated /// instances since the last call to MarkCurrentObjects. /// GetNewObjects does return the newly allocated objects as object array /// </summary> static void InstanceTracking() { using (var dumper = new MemoryDumper()) // if you have problems use to see the debugger windows true,true)) { dumper.MarkCurrentObjects(); Allocate(); ILookup<Type, object> newObjects = dumper.GetNewObjects() .ToLookup( x => x.GetType() ); Console.WriteLine("New Strings:"); foreach (var newStr in newObjects[typeof(string)] ) { Console.WriteLine("Str: {0}", newStr); } } } … New Strings: Str: qqd Str: String data: Str: String data: 0 Str: String data: 1 … This is really hot stuff. Not only you can get heap statistics but you can directly examine the new objects and make queries upon them. When I do find more time I can reconstruct the object root graph from it from my own process. It this cool or what? You can also peek into the Finalization Queue to check if you did accidentally forget to dispose a whole bunch of objects … /// <summary> /// .NET 4.0 or above only. Get all finalizable objects which are ready for finalization and have no other object roots anymore. /// </summary> static void NotYetFinalizedObjects() { using (var dumper = new MemoryDumper()) { object[] finalizable = dumper.GetObjectsReadyForFinalization(); Console.WriteLine("Currently {0} objects of types {1} are ready for finalization. Consider disposing them before.", finalizable.Length, String.Join(",", finalizable.ToLookup( x=> x.GetType() ) .Select( x=> x.Key.Name)) ); } } How does it work? The W of WMemoryProfiler is a good hint. It does employ Windbg and SOS dll to do the heavy lifting and concentrates on an easy to use Api which does hide completely Windbg. If you do not want to see Windbg you will never see it. In my experience the most complex thing is actually to download Windbg from the Windows 8 Stanalone SDK. This is described in the Readme and the exception you are greeted with if it is missing in much greater detail. So I will not go into this here.   What Next? Depending on the feedback I do get I can imagine some features which might be useful as well Calculate first order GC Roots from the actual object graph Identify global statics in Types in object graph Support read out of finalization queue of .NET 2.0 as well. Support Memory Dump analysis (again a feature only supported by commercial profilers in their professional editions if it is supported at all) Deserialize objects from a memory dump into a live process back (this would need some more investigation but it is doable) The last item needs some explanation. Why on earth would you want to do that? The basic idea is to store in your live process some logging/tracing data which can become quite big but since it is never written to it is very fast to generate. When your process crashes with a memory dump you could transfer this data structure back into a live viewer which can then nicely display your program state at the point it did crash. This is an advanced trouble shooting technique I have not seen anywhere yet but it could be quite useful. You can have here a look at the current feature list of WMemoryProfiler with some examples.   How To Get Started? First I would download the released source package (it is tiny). And compile the complete project. Then you can compile the Example project (it has this name) and uncomment in the main method the scenario you want to check out. If you are greeted with an exception it is time to install the Windows 8 Standalone SDK which is described in great detail in the exception text. Thats it for the first round. I have seen something more limited in the Java world some years ago (now I cannot find the link anymore) but anyway. Now we have something much better.

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• Pirates, Treasure Chests and Architectural Mapping

  Pirate 1: Why do pirates create treasure maps? Pirate 2: I do not know.Pirate 1: So they can find their gold. Yes, that was a bad joke, but it does illustrate a point. Pirates are known for drawing treasure maps to their most prized possession. These documents detail the decisions pirates made in order to hide and find their chests of gold. The map allows them to trace the steps they took originally to hide their treasure so that they may return. As software engineers, programmers, and architects we need to treat software implementations much like our treasure chest. Why is software like a treasure chest? It cost money, time,  and resources to develop (Usually) It can make or save money, time, and resources (Hopefully) If we operate under the assumption that software is like a treasure chest then wouldn’t make sense to document the steps, rationale, concerns, and decisions about how it was designed? Pirates are notorious for documenting where they hide their treasure.  Shouldn’t we as creators of software do the same? By documenting our design decisions and rationale behind them will help others be able to understand and maintain implemented systems. This can only be done if the design decisions are correctly mapped to its corresponding implementation. This allows for architectural decisions to be traced from the conceptual model, architectural design and finally to the implementation. Mapping gives software professional a method to trace the reason why specific areas of code were developed verses other options. Just like the pirates we need to able to trace our steps from the start of a project to its implementation,  so that we will understand why specific choices were chosen. The traceability of a software implementation that actually maps back to its originating design decisions is invaluable for ensuring that architectural drifting and erosion does not take place. The drifting and erosion is prevented by allowing others to understand the rational of why an implementation was created in a specific manor or methodology The process of mapping distinct design concerns/decisions to the location of its implemented is called traceability. In this context traceability is defined as method for connecting distinctive software artifacts. This process allows architectural design models and decisions to be directly connected with its physical implementation. The process of mapping architectural design concerns to a software implementation can be very complex. However, most design decision can be placed in  a few generalized categories. Commonly Mapped Design Decisions Design Rationale Components and Connectors Interfaces Behaviors/Properties Design rational is one of the hardest categories to map directly to an implementation. Typically this rational is mapped or document in code via comments. These comments consist of general design decisions and reasoning because they do not directly refer to a specific part of an application. They typically focus more on the higher level concerns. Components and connectors can directly be mapped to architectural concerns. Typically concerns subdivide an application in to distinct functional areas. These functional areas then can map directly back to their originating concerns.Interfaces can be mapped back to design concerns in one of two ways. Interfaces that pertain to specific function definitions can be directly mapped back to its originating concern(s). However, more complicated interfaces require additional analysis to ensure that the proper mappings are created. Depending on the complexity some Behaviors\Properties can be translated directly into a generic implementation structure that is ready for business logic. In addition, some behaviors can be translated directly in to an actual implementation depending on the complexity and architectural tools used. Mapping design concerns to an implementation is a lot of work to maintain, but is doable. In order to ensure that concerns are mapped correctly and that an implementation correctly reflects its design concerns then one of two standard approaches are usually used. All Changes Come From ArchitectureBy forcing all application changes to come through the architectural model prior to implementation then the existing mappings will be used to locate where in the implementation changes need to occur. Allow Changes From Implementation Or Architecture By allowing changes to come from the implementation and/or the architecture then the other area must be kept in sync. This methodology is more complex compared to the previous approach.  One reason to justify the added complexity for an application is due to the fact that this approach tends to detect and prevent architectural drift and erosion. Additionally, this approach is usually maintained via software because of the complexity. Reference:Taylor, R. N., Medvidovic, N., & Dashofy, E. M. (2009). Software architecture: Foundations, theory, and practice Hoboken, NJ: John Wiley & Sons  

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• How to set up spf records to send mail from google hosted apps to gmail addresses

  - by Chris Adams

  Hi there, I'm trying to work out why email I send from one domain I own is rejected by another that I own, and while I think it may be related to how I've setup spf records, I'm not sure what steps I need to take to fix it. Here's the error message I receive: Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550-Verification failed for <[email protected]> 550-No Such User Here 550 Sender verify failed (state 14). Here's the response from [email protected] Delivered-To: [email protected] Received: by 10.86.92.9 with SMTP id p9cs85371fgb; Wed, 2 Sep 2009 22:33:32 -0700 (PDT) Received: by 10.90.205.4 with SMTP id c4mr2406190agg.29.1251956007562; Wed, 02 Sep 2009 22:33:27 -0700 (PDT) Return-Path: <[email protected]> Received: from verifier.port25.com (207-36-201-235.ptr.primarydns.com [207.36.201.235]) by mx.google.com with ESMTP id 26si831174aga.24.2009.09.02.22.33.25; Wed, 02 Sep 2009 22:33:26 -0700 (PDT) Received-SPF: pass (google.com: domain of [email protected] designates 207.36.201.235 as permitted sender) client-ip=207.36.201.235; Authentication-Results: mx.google.com; spf=pass (google.com: domain of [email protected] designates 207.36.201.235 as permitted sender) [email protected]; dkim=pass [email protected] DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=auth; d=port25.com; h=Date:From:To:Subject:Message-Id:In-Reply-To; [email protected]; bh=GRMrcnoucTl4upzqJYTG5sOZMLU=; b=uk6TjADEyZVRkceQGjH94ZzfVeRTsiZPzbXuhlqDt1m+kh1zmdUEoiTOzd89ryCHMbVcnG1JajBj 5vOMKYtA3g== DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=auth; d=port25.com; b=NqKCPK00Xt49lbeO009xy4ZRgMGpghvcgfhjNy7+qI89XKTzi6IUW0hYqCQyHkd2p5a1Zjez2ZMC l0u9CpZD3Q==; Received: from verifier.port25.com (127.0.0.1) by verifier.port25.com (PowerMTA(TM) v3.6a1) id hjt9pq0hse8u for <[email protected]>; Thu, 3 Sep 2009 01:26:52 -0400 (envelope-from <[email protected]>) Date: Thu, 3 Sep 2009 01:26:52 -0400 From: [email protected] To: [email protected] Subject: Authentication Report Message-Id: <[email protected]> Precedence: junk (auto_reply) In-Reply-To: <[email protected]> This message is an automatic response from Port25's authentication verifier service at verifier.port25.com. The service allows email senders to perform a simple check of various sender authentication mechanisms. It is provided free of charge, in the hope that it is useful to the email community. While it is not officially supported, we welcome any feedback you may have at <[email protected]>. Thank you for using the verifier, The Port25 Solutions, Inc. team ========================================================== Summary of Results ========================================================== SPF check: pass DomainKeys check: neutral DKIM check: neutral Sender-ID check: pass SpamAssassin check: ham ========================================================== Details: ========================================================== HELO hostname: fg-out-1718.google.com Source IP: 72.14.220.158 mail-from: [email protected] ---------------------------------------------------------- SPF check details: ---------------------------------------------------------- Result: pass ID(s) verified: [email protected] DNS record(s): stemcel.co.uk. 14400 IN TXT "v=spf1 include:aspmx.googlemail.com ~all" aspmx.googlemail.com. 7200 IN TXT "v=spf1 redirect=_spf.google.com" _spf.google.com. 300 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ?all" ---------------------------------------------------------- DomainKeys check details: ---------------------------------------------------------- Result: neutral (message not signed) ID(s) verified: [email protected] DNS record(s): ---------------------------------------------------------- DKIM check details: ---------------------------------------------------------- Result: neutral (message not signed) ID(s) verified: NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25's PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM. ---------------------------------------------------------- Sender-ID check details: ---------------------------------------------------------- Result: pass ID(s) verified: [email protected] DNS record(s): stemcel.co.uk. 14400 IN TXT "v=spf1 include:aspmx.googlemail.com ~all" aspmx.googlemail.com. 7200 IN TXT "v=spf1 redirect=_spf.google.com" _spf.google.com. 300 IN TXT "v=spf1 ip4:216.239.32.0/19 ip4:64.233.160.0/19 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:209.85.128.0/17 ip4:66.102.0.0/20 ip4:74.125.0.0/16 ip4:64.18.0.0/20 ip4:207.126.144.0/20 ?all" ---------------------------------------------------------- SpamAssassin check details: ---------------------------------------------------------- SpamAssassin v3.2.5 (2008-06-10) Result: ham (-2.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.0 HTML_MESSAGE BODY: HTML included in message I've registered the spf records for my domain, as advised here Both domains pass validate according to Kitterman's spf record testing tools, so I'm somewhat confused about this. I also have the catchall address set up on the stemcel.co.uk domain here, but I don't have one setup for chrisadams.me.uk. Instead, we have the following forwarders setup [email protected] to [email protected] [email protected] to [email protected] [email protected] to [email protected] [email protected] to [email protected] Any ideas how to get this working? I'm not sure what I should be looking for here.

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• DKIM, SPF, PTR records are not working properly with my domain

  - by shihon

  I configured my server and well authenticate email system with DKIM key, SPF record and PTR records, when i start to sent out mails from phplist interface to my users ~50000, my domain is spammed by google. In headers, signed by and mailed by tag shows by my domain : appmail.co, I also test my domain via check mail provide by port25, report is: This message is an automatic response from Port25's authentication verifier service at verifier.port25.com. The service allows email senders to perform a simple check of various sender authentication mechanisms. It is provided free of charge, in the hope that it is useful to the email community. While it is not officially supported, we welcome any feedback you may have at . Thank you for using the verifier, The Port25 Solutions, Inc. team ========================================================== Summary of Results SPF check: pass DomainKeys check: neutral DKIM check: pass Sender-ID check: pass SpamAssassin check: ham ========================================================== Details: HELO hostname: app.appmail.co Source IP: 108.179.192.148 mail-from: [email protected] SPF check details: Result: pass ID(s) verified: [email protected] DNS record(s): appmail.co. SPF (no records) appmail.co. 14400 IN TXT "v=spf1 +a +mx +ip4:108.179.192.148 ?all" appmail.co. 14400 IN A 108.179.192.148 DomainKeys check details: Result: neutral (message not signed) ID(s) verified: [email protected] DNS record(s): DKIM check details: Result: pass (matches From: [email protected]) ID(s) verified: header.d=appmail.co Canonicalized Headers: content-type:multipart/alternative;'20'boundary=047d7b2eda75d8544d04c17b6841'0D''0A' to:[email protected]'0D''0A' from:shashank'20'sharma'20'<[email protected]>'0D''0A' subject:Test'0D''0A' message-id:<CADnDhbH9aDBk3Ho2-CrG7gwOoD6RNX0sFq4bWL64+kmo=9HjWg@mail.gmail.com>'0D''0A' date:Sat,'20'2'20'Jun'20'2012'20'16:44:50'20'+0530'0D''0A' mime-version:1.0'0D''0A' dkim-signature:v=1;'20'a=rsa-sha256;'20'q=dns/txt;'20'c=relaxed/relaxed;'20'd=appmail.co;'20's=default;'20'h=Content-Type:To:From:Subject:Message-ID:Date:MIME-Version;'20'bh=GS6uwlT+weKcrrLJ2I+cjBtWPq9nvhwRlNAJebOiQOk=;'20'b=; Canonicalized Body: --047d7b2eda75d8544d04c17b6841'0D''0A' Content-Type:'20'text/plain;'20'charset=UTF-8'0D''0A' '0D''0A' Hello'20'Senders'0D''0A' '0D''0A' --047d7b2eda75d8544d04c17b6841'0D''0A' Content-Type:'20'text/html;'20'charset=UTF-8'0D''0A' '0D''0A' Hello'20'Senders'0D''0A' '0D''0A' --047d7b2eda75d8544d04c17b6841--'0D''0A' DNS record(s): default._domainkey.appmail.co. 14400 IN TXT "v=DKIM1; k=rsa; p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhALGCOdMeZRxRHoatH7/KCvI1CKS0wOOsTAq0LLgPsOpMolifpVQDKOWT2zq/6LHVmDVjXLbnWO2d4ry/riy7ei66pLpnAV5ceIUSjBRusI8jcF9CZhPrh/OImsKVUb9ceQIDAQAB;" NOTE: DKIM checking has been performed based on the latest DKIM specs (RFC 4871 or draft-ietf-dkim-base-10) and verification may fail for older versions. If you are using Port25's PowerMTA, you need to use version 3.2r11 or later to get a compatible version of DKIM. Sender-ID check details: Result: pass ID(s) verified: [email protected] DNS record(s): appmail.co. SPF (no records) appmail.co. 14400 IN TXT "v=spf1 +a +mx +ip4:108.179.192.148 ?all" appmail.co. 14400 IN A 108.179.192.148 SpamAssassin check details: SpamAssassin v3.3.1 (2010-03-16) Result: ham (-0.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message -0.5 BAYES_05 BODY: Bayes spam probability is 1 to 5% [score: 0.0288] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.5 SINGLE_HEADER_1K A single header contains 1K-2K characters ========================================================== Original Email Return-Path: <[email protected]> Received: from app.appmail.co (108.179.192.148) by verifier.port25.com id hp7qqo11u9cc for <[email protected]>; Sat, 2 Jun 2012 07:14:52 -0400 (envelope-from <[email protected]>) Authentication-Results: verifier.port25.com; spf=pass [email protected] Authentication-Results: verifier.port25.com; domainkeys=neutral (message not signed) [email protected] Authentication-Results: verifier.port25.com; dkim=pass (matches From: [email protected]) header.d=appmail.co Authentication-Results: verifier.port25.com; sender-id=pass [email protected] DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=appmail.co; s=default; h=Content-Type:To:From:Subject:Message-ID:Date:MIME-Version; bh=GS6uwlT+weKcrrLJ2I+cjBtWPq9nvhwRlNAJebOiQOk=;b=pNw3UQNMoNyZ2Ujv8omHGodKVu/55S8YdBEsA5TbRciga/H7f+5noiKvo60vU6oXYyzVKeozFHDoOEMV6m5UTgkdBefogl+9cUIbt5CSrTWA97D7tGS97JblTDXApbZH; Received: from mail-pb0-f46.google.com ([209.85.160.46]:57831) by app.appmail.co with esmtpa (Exim 4.77) (envelope-from <[email protected]>) id 1SamIF-00055f-Om for [email protected]; Sat, 02 Jun 2012 16:44:51 +0530 Received: by pbbrp8 with SMTP id rp8so4165728pbb.5 for <[email protected]>; Sat, 02 Jun 2012 04:14:51 -0700 (PDT) MIME-Version: 1.0 Received: by 10.68.216.33 with SMTP id on1mr19414885pbc.105.1338635690988; Sat, 02 Jun 2012 04:14:50 -0700 (PDT) Received: by 10.143.66.13 with HTTP; Sat, 2 Jun 2012 04:14:50 -0700 (PDT) Date: Sat, 2 Jun 2012 16:44:50 +0530 Message-ID: <CADnDhbH9aDBk3Ho2-CrG7gwOoD6RNX0sFq4bWL64+kmo=9HjWg@mail.gmail.com> Subject: Test From: shashank sharma <[email protected]> To: [email protected] Content-Type: multipart/alternative; boundary=047d7b2eda75d8544d04c17b6841 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - app.appmail.co X-AntiAbuse: Original Domain - verifier.port25.com X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - appmail.co --047d7b2eda75d8544d04c17b6841 Content-Type: text/plain; charset=UTF-8 Hello Senders --047d7b2eda75d8544d04c17b6841 Content-Type: text/html; charset=UTF-8 Hello Senders --047d7b2eda75d8544d04c17b6841-- I also tried to send mail on yahoo , rediff but i get mails in spam. Please help me to sort out this issue

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• Flushing a queue using AMQP, Rabbit, and Ruby

  - by jeffshantz

  I'm developing a system in Ruby that is going to make use of RabbitMQ to send messages to a queue as it does some work. I am using: Ruby 1.9.1 Stable RabbitMQ 1.7.2 AMQP gem v0.6.7 (http://github.com/tmm1/amqp) Most of the examples I have seen on this gem have their publish calls in an EM.add_periodic_timer block. This doesn't work for what I suspect is a vast majority of use cases, and certainly not for mine. I need to publish a message as I complete some work, so putting a publish statement in an add_periodic_timer block doesn't suffice. So, I'm trying to figure out how to publish a few messages to a queue, and then "flush" it, so that any messages I've published are then delivered to my subscribers. To give you an idea of what I mean, consider the following publisher code: #!/usr/bin/ruby require 'rubygems' require 'mq' MESSAGES = ["hello","goodbye","test"] AMQP.start do queue = MQ.queue('testq') messages_published = 0 while (messages_published < 50) if (rand() < 0.4) message = MESSAGES[rand(MESSAGES.size)] puts "#{Time.now.to_s}: Publishing: #{message}" queue.publish(message) messages_published += 1 end sleep(0.1) end AMQP.stop do EM.stop end end So, this code simply loops, publishing a message with 40% probability on each iteration of the loop, and then sleeps for 0.1 seconds. It does this until 50 messages have been published, and then stops AMQP. Of course, this is just a proof of concept. Now, my subscriber code: #!/usr/bin/ruby require 'rubygems' require 'mq' AMQP.start do queue = MQ.queue('testq') queue.subscribe do |header, msg| puts "#{Time.now.to_s}: Received #{msg}" end end So, we just subscribe to the queue, and for each message received, we print it out. Great, except that the subscriber only receives all 50 messages when the publisher calls AMQP.stop. Here's the output from my publisher. It has been truncated in the middle for brevity: $ ruby publisher.rb 2010-04-14 21:45:42 -0400: Publishing: test 2010-04-14 21:45:42 -0400: Publishing: hello 2010-04-14 21:45:42 -0400: Publishing: test 2010-04-14 21:45:43 -0400: Publishing: test 2010-04-14 21:45:44 -0400: Publishing: test 2010-04-14 21:45:44 -0400: Publishing: goodbye 2010-04-14 21:45:45 -0400: Publishing: goodbye 2010-04-14 21:45:45 -0400: Publishing: test 2010-04-14 21:45:45 -0400: Publishing: test . . . 2010-04-14 21:45:55 -0400: Publishing: test 2010-04-14 21:45:55 -0400: Publishing: test 2010-04-14 21:45:55 -0400: Publishing: test 2010-04-14 21:45:55 -0400: Publishing: goodbye Next, the output from my subscriber: $ ruby consumer.rb 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received hello 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received goodbye 2010-04-14 21:45:56 -0400: Received goodbye 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test . . . 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received test 2010-04-14 21:45:56 -0400: Received goodbye If you note the timestamps in the output, the subscriber only receives all of the messages once the publisher has stopped AMQP and exited. So, being an AMQP newb, how can I get my messages to deliver immediately? I tried putting AMQP.start and AMQP.stop in the body of the while loop of the publisher, but then only the first message gets delivered -- though strangely, if I turn on logging, there are no error messages reported by the server and the messages do get sent to the queue, but never get received by the subscriber. Suggestions would be much appreciated. Thanks for reading.

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