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  • New .NET Library for Accessing the Survey Monkey API

    - by Ben Emmett
    I’ve used Survey Monkey’s API for a while, and though it’s pretty powerful, there’s a lot of boilerplate each time it’s used in a new project, and the json it returns needs a bunch of processing to be able to use the raw information. So I’ve finally got around to releasing a .NET library you can use to consume the API more easily. The main advantages are: Only ever deal with strongly-typed .NET objects, making everything much more robust and a lot faster to get going Automatically handles things like rate-limiting and paging through results Uses combinations of endpoints to get all relevant data for you, and processes raw response data to map responses to questions To start, either install it using NuGet with PM> Install-Package SurveyMonkeyApi (easier option), or grab the source from https://github.com/bcemmett/SurveyMonkeyApi if you prefer to build it yourself. You’ll also need to have signed up for a developer account with Survey Monkey, and have both your API key and an OAuth token. A simple usage would be something like: string apiKey = "KEY"; string token = "TOKEN"; var sm = new SurveyMonkeyApi(apiKey, token); List<Survey> surveys = sm.GetSurveyList(); The surveys object is now a list of surveys with all the information available from the /surveys/get_survey_list API endpoint, including the title, id, date it was created and last modified, language, number of questions / responses, and relevant urls. If there are more than 1000 surveys in your account, the library pages through the results for you, making multiple requests to get a complete list of surveys. All the filtering available in the API can be controlled using .NET objects. For example you might only want surveys created in the last year and containing “pineapple” in the title: var settings = new GetSurveyListSettings { Title = "pineapple", StartDate = DateTime.Now.AddYears(-1) }; List<Survey> surveys = sm.GetSurveyList(settings); By default, whenever optional fields can be requested with a response, they will all be fetched for you. You can change this behaviour if for some reason you explicitly don’t want the information, using var settings = new GetSurveyListSettings { OptionalData = new GetSurveyListSettingsOptionalData { DateCreated = false, AnalysisUrl = false } }; Survey Monkey’s 7 read-only endpoints are supported, and the other 4 which make modifications to data might be supported in the future. The endpoints are: Endpoint Method Object returned /surveys/get_survey_list GetSurveyList() List<Survey> /surveys/get_survey_details GetSurveyDetails() Survey /surveys/get_collector_list GetCollectorList() List<Collector> /surveys/get_respondent_list GetRespondentList() List<Respondent> /surveys/get_responses GetResponses() List<Response> /surveys/get_response_counts GetResponseCounts() Collector /user/get_user_details GetUserDetails() UserDetails /batch/create_flow Not supported Not supported /batch/send_flow Not supported Not supported /templates/get_template_list Not supported Not supported /collectors/create_collector Not supported Not supported The hierarchy of objects the library can return is Survey List<Page> List<Question> QuestionType List<Answer> List<Item> List<Collector> List<Response> Respondent List<ResponseQuestion> List<ResponseAnswer> Each of these classes has properties which map directly to the names of properties returned by the API itself (though using PascalCasing which is more natural for .NET, rather than the snake_casing used by SurveyMonkey). For most users, Survey Monkey imposes a rate limit of 2 requests per second, so by default the library leaves at least 500ms between requests. You can request higher limits from them, so if you want to change the delay between requests just use a different constructor: var sm = new SurveyMonkeyApi(apiKey, token, 200); //200ms delay = 5 reqs per sec There’s a separate cap of 1000 requests per day for each API key, which the library doesn’t currently enforce, so if you think you’ll be in danger of exceeding that you’ll need to handle it yourself for now.  To help, you can see how many requests the current instance of the SurveyMonkeyApi object has made by reading its RequestsMade property. If the library encounters any errors, including communicating with the API, it will throw a SurveyMonkeyException, so be sure to handle that sensibly any time you use it to make calls. Finally, if you have a survey (or list of surveys) obtained using GetSurveyList(), the library can automatically fill in all available information using sm.FillMissingSurveyInformation(surveys); For each survey in the list, it uses the other endpoints to fill in the missing information about the survey’s question structure, respondents, and responses. This results in at least 5 API calls being made per survey, so be careful before passing it a large list. It also joins up the raw response information to the survey’s question structure, so that for each question in a respondent’s set of replies, you can access a ProcessedAnswer object. For example, a response to a dropdown question (from the /surveys/get_responses endpoint) might be represented in json as { "answers": [ { "row": "9384627365", } ], "question_id": "615487516" } Separately, the question’s structure (from the /surveys/get_survey_details endpoint) might have several possible answers, one of which might look like { "text": "Fourth item in dropdown list", "visible": true, "position": 4, "type": "row", "answer_id": "9384627365" } The library understands how this mapping works, and uses that to give you the following ProcessedAnswer object, which first describes the family and type of question, and secondly gives you the respondent’s answers as they relate to the question. Survey Monkey has many different question types, with 11 distinct data structures, each of which are supported by the library. If you have suggestions or spot any bugs, let me know in the comments, or even better submit a pull request .

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  • BizTalk host throttling &ndash; Singleton pattern and High database size

    - by S.E.R.
    Originally posted on: http://geekswithblogs.net/SERivas/archive/2013/06/30/biztalk-host-throttling-ndash-singleton-pattern-and-high-database-size.aspxI have worked for some days around the singleton pattern (for those unfamiliar with it, read this post by Victor Fehlberg) and have come across a few very interesting posts, among which one dealt with performance issues (here, also by Victor Fehlberg). Simply put: if you have an orchestration which implements the singleton pattern, then performances will continuously decrease as the orchestration receives and consumes messages, and that behavior is more obvious when the orchestration never ends (ie : it keeps looping and never terminates or completes). As I experienced the same kind of problem (actually I was alerted by SCOM, which told me that the host was being throttled because of High database size), I thought it would be a good idea to dig a little bit a see what happens deep inside BizTalk and thus understand the reasons for this behavior. NOTE: in this article, I will focus on this High database size throttling condition. I will try and work on the other conditions in some not too distant future… Test conditions The singleton orchestration For the purpose of this study, I have created the following orchestration, which is a very basic implementation of a singleton that piles up incoming messages, then does something else when a certain timeout has been reached without receiving another message: Throttling settings I have two distinct hosts : one that hosts the receive port (basic FILE port) : Ports_ReceiveHostone that hosts the orchestration : ProcessingHost In order to emphasize the throttling mechanism, I have modified the throttling settings for each of these hosts are as follows (all other parameters are set to the default value): [Throttling thresholds] Message count in database: 500 (default value : 50000) Evolution of performance counters when submitting messages Since we are investigating the High database size throttling condition, here are the performance counter that we should take a look at (all of them are in the BizTalk:Message Agent performance object): Database sizeHigh database sizeMessage delivery throttling stateMessage publishing throttling stateMessage delivery delay (ms)Message publishing delay (ms)Message delivery throttling state durationMessage publishing throttling state duration (If you are not used to Perfmon, I strongly recommend that you start using it right now: it is a wonderful tool that allows you to open the hood and see what is going on inside BizTalk – and other systems) Database size It is quite obvious that we will start by watching the database size and high database size counters, just to see when the first reaches the configured threshold (500) and when the second rings the alarm. NOTE : During this test I submitted 600 messages, one message at a time every 10ms to see the evolution of the counters we have previously selected. It might not show very well on this screenshot, but here is what happened: From 15:46:50 to 15:47:50, the database size for the Ports_ReceiveHost host (blue line) kept growing until it reached a maximum of 504.At 15:47:50, the high database size alert fires At first I was surprised by this result: why is it the database size of the receiving host that keeps growing since it is the processing host that piles up messages? Actually, it makes total sense. This counter measures the size of the database queue that is being filled by the host, not consumed. Therefore, the high database size alert is raised on the host that fills the queue: Ports_ReceiveHost. More information is available on the Public MPWiki page. Now, looking at the Message publishing throttling state for the receiving host (green line), we can see that a throttling condition has been reached at 15:47:50: We can also see that the Message publishing delay(ms) (blue line) has begun growing slowly from this point. All of this explains why performances keep decreasing when a singleton keeps processing new messages: the database size grows and when it has exceeded the Message count in database threshold, the host is throttled and the publishing delay keeps increasing. Digging further So, what happens to the database queue then? Is it flushed some day or does it keep growing and growing indefinitely? The real question being: will the host be throttled forever because of this singleton? To answer this question, I set the Message count in database threshold to 20 (this value is very low in order not to wait for too long, otherwise I certainly would have fallen asleep in front of my screen) and I submitted 30 messages. The test was started at 18:26. At 18:56 (ie : exactly 30min later) the throttling was stopped and the database size was divided by 2. 30 min later again, the database size had dropped to almost zero: I guess I’ll have to find some documentation and do some more testing before I sort this out! My guess is that some maintenance job is at work here, though I cannot tell which one Digging even further If we take a look at the Message delivery throttling state counter for the processing host, we can see that this host was also throttled during the submission of the 600 documents: The value for the counter was 1, meaning that Message delivery incoming rate for the host instance exceeds the Message delivery outgoing rate * the specified Rate overdrive factor (percent) value. We will see this another day… :) A last word Let’s end this article with a warning: DO NOT CHANGE THE THROTTLING SETTINGS LIGHTLY! The temptation can be great to just bypass throttling by setting very high values for each parameter (or zero in some cases, which simply disables throttling). Nevertheless, always keep in mind that this mechanism is here for a very good reason: prevent your BizTalk infrastructure from exploding!! So whatever you do with those settings, do a lot of testing and benchmarking!

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  • Unique Business Value vs. Unique IT

    - by barry.perkins
    When the age of computing started, technology was new, exciting, full of potential and had a long way to grow. Vendor architectures were proprietary, and limited in function at first, growing in capability and complexity over time. There were few if any "standards", let alone "open standards" and the concepts of "open systems", and "open architectures" were far in the future. Companies employed intelligent, talented and creative people to implement the best possible solutions for their company. At first, those solutions were "unique" to each company. As time progressed, standards emerged, companies shared knowledge, business capability supplied by technology grew, and companies continued to expand their use of technology. Taking advantage of change required companies to struggle through periodic "revolutionary" change cycles, struggling through costly changes that were fraught with risk, resulted in solutions with an increasingly shorter half-life, and frequently required altering existing business processes and retraining employees and partner businesses. The pace of technological invention and implementation grew at an ever increasing rate, making the "revolutionary" approach based upon "proprietary" or "closed" architectures or technologies no longer viable. Concurrent with the advancement of technology, the rate of change in business increased, leading us to the incredibly fast paced, highly charged, and competitive global economy that we have today, where the most successful companies are companies that are good at implementing, leveraging and exploiting change. Fast forward to today, a world where dramatic changes in business and technology happen continually, a world where "evolutionary" change is crucial. Companies can no longer afford to build "unique IT", nor can they afford regular intervals of "revolutionary" change, with the associated costs and risks. Human ingenuity was once again up to the task, turning technology into a platform supporting business through evolutionary change, by employing "open": open standards; open systems; open architectures; and open solutions. Employing "open", enables companies to implement systems based upon technology, capability and standards that will evolve over time, providing a solid platform upon which a company can drive business needs, requirements, functions, and processes down into the technology, rather than exposing technology to the business, allowing companies to focus on providing "unique business value" rather than "unique IT". The big question! Does moving from "older" technology that no longer meets the needs of today's business, to new "open" technology require yet another "revolutionary change"? A "revolutionary" change with a short half-life, camouflaging reality with great marketing? The answer is "perhaps". With the endless options available to choose from, it is entirely possible to implement a solution that may work well today, but in 5 years time will become yet another albatross for the company to bear. Some solutions may look good today, solving a budget challenge by reducing cost, or solving a specific tactical challenge, but result in highly complex environments, that may be difficult to manage and maintain and limit the future potential of your business. Put differently, some solutions might push today's challenge into the future, resulting in a more complex and expensive solution. There is no such thing as a "1 size fits all" IT solution for business. If all companies implemented business solutions based upon technology that required, or forced the same business processes across all businesses in an industry, it would be extremely difficult to show competitive advantage through "unique business value". It would be equally difficult to "evolve" to meet or exceed business needs and keep up with today's rapid pace of change. How does one ensure that they do not jump from one trap directly into another? Or to put it positively, there are solutions available today that can address these challenges and issues. How does one ensure that the buying decision of today will serve the business well for years into the future? Intelligent & Informed decisions - "buying right" In a previous blog entry, we discussed the value of linking tactical to strategic The key is driving the focus to what is best for your business, handling today's tactical issues while also aligning with a roadmap/strategy that is tightly aligned with your strategic business objectives. When considering the plethora of possible options that provide various approaches to solving today's complex business problems, it is extremely important to ensure that vendors supplying those options, focus on what is best for your business, supplying sufficient information, providing adequate answers to questions, addressing challenges, issues, concerns and objections honestly and openly, and focus on supplying solutions that are tailored for, and deliver the most business value possible for your business. Here are a few questions to consider relative to the proposed options that should help ensure that today's solution doesn't become tomorrow's problem. Do the proposed solutions: Solve the problem(s) you are trying to address? Provide a solid foundation upon which to grow/enhance your business? Provide tactical gains that align with and enable your strategic business goals/objectives? Provide an infrastructure that can be leveraged with subsequent projects? Solve problems for the business overall, the lines of business, or just IT? Simplify your current environment Provide the basis for business: Efficiency Agility Clarity governance, risk, compliance real time business visibility and trend analysis Does your IT staff have the knowledge/experience to successfully manage the proposed systems once they are deployed in production? Done well, you will be presented with options tailored to your business, that enable you to drive the "unique business value" necessary to help your business stand out from others, creating a distinct competitive advantage, delivering what your customers need, when they need it, so you can attract new customers, new business, and grow top line revenue, all at a cost that provides a strong Return on Investment/Return on Assets. The net result is growth with managed cost providing significantly improved profit margin and shareholder value.

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  • World Record Oracle Business Intelligence Benchmark on SPARC T4-4

    - by Brian
    Oracle's SPARC T4-4 server configured with four SPARC T4 3.0 GHz processors delivered the first and best performance of 25,000 concurrent users on Oracle Business Intelligence Enterprise Edition (BI EE) 11g benchmark using Oracle Database 11g Release 2 running on Oracle Solaris 10. A SPARC T4-4 server running Oracle Business Intelligence Enterprise Edition 11g achieved 25,000 concurrent users with an average response time of 0.36 seconds with Oracle BI server cache set to ON. The benchmark data clearly shows that the underlying hardware, SPARC T4 server, and the Oracle BI EE 11g (11.1.1.6.0 64-bit) platform scales within a single system supporting 25,000 concurrent users while executing 415 transactions/sec. The benchmark demonstrated the scalability of Oracle Business Intelligence Enterprise Edition 11g 11.1.1.6.0, which was deployed in a vertical scale-out fashion on a single SPARC T4-4 server. Oracle Internet Directory configured on SPARC T4 server provided authentication for the 25,000 Oracle BI EE users with sub-second response time. A SPARC T4-4 with internal Solid State Drive (SSD) using the ZFS file system showed significant I/O performance improvement over traditional disk for the Web Catalog activity. In addition, ZFS helped get past the UFS limitation of 32767 sub-directories in a Web Catalog directory. The multi-threaded 64-bit Oracle Business Intelligence Enterprise Edition 11g and SPARC T4-4 server proved to be a successful combination by providing sub-second response times for the end user transactions, consuming only half of the available CPU resources at 25,000 concurrent users, leaving plenty of head room for increased load. The Oracle Business Intelligence on SPARC T4-4 server benchmark results demonstrate that comprehensive BI functionality built on a unified infrastructure with a unified business model yields best-in-class scalability, reliability and performance. Oracle BI EE 11g is a newer version of Business Intelligence Suite with richer and superior functionality. Results produced with Oracle BI EE 11g benchmark are not comparable to results with Oracle BI EE 10g benchmark. Oracle BI EE 11g is a more difficult benchmark to run, exercising more features of Oracle BI. Performance Landscape Results for the Oracle BI EE 11g version of the benchmark. Results are not comparable to the Oracle BI EE 10g version of the benchmark. Oracle BI EE 11g Benchmark System Number of Users Response Time (sec) 1 x SPARC T4-4 (4 x SPARC T4 3.0 GHz) 25,000 0.36 Results for the Oracle BI EE 10g version of the benchmark. Results are not comparable to the Oracle BI EE 11g version of the benchmark. Oracle BI EE 10g Benchmark System Number of Users 2 x SPARC T5440 (4 x SPARC T2+ 1.6 GHz) 50,000 1 x SPARC T5440 (4 x SPARC T2+ 1.6 GHz) 28,000 Configuration Summary Hardware Configuration: SPARC T4-4 server 4 x SPARC T4-4 processors, 3.0 GHz 128 GB memory 4 x 300 GB internal SSD Storage Configuration: "> Sun ZFS Storage 7120 16 x 146 GB disks Software Configuration: Oracle Solaris 10 8/11 Oracle Solaris Studio 12.1 Oracle Business Intelligence Enterprise Edition 11g (11.1.1.6.0) Oracle WebLogic Server 10.3.5 Oracle Internet Directory 11.1.1.6.0 Oracle Database 11g Release 2 Benchmark Description Oracle Business Intelligence Enterprise Edition (Oracle BI EE) delivers a robust set of reporting, ad-hoc query and analysis, OLAP, dashboard, and scorecard functionality with a rich end-user experience that includes visualization, collaboration, and more. The Oracle BI EE benchmark test used five different business user roles - Marketing Executive, Sales Representative, Sales Manager, Sales Vice-President, and Service Manager. These roles included a maximum of 5 different pre-built dashboards. Each dashboard page had an average of 5 reports in the form of a mix of charts, tables and pivot tables, returning anywhere from 50 rows to approximately 500 rows of aggregated data. The test scenario also included drill-down into multiple levels from a table or chart within a dashboard. The benchmark test scenario uses a typical business user sequence of dashboard navigation, report viewing, and drill down. For example, a Service Manager logs into the system and navigates to his own set of dashboards using Service Manager. The BI user selects the Service Effectiveness dashboard, which shows him four distinct reports, Service Request Trend, First Time Fix Rate, Activity Problem Areas, and Cost Per Completed Service Call spanning 2002 to 2005. The user then proceeds to view the Customer Satisfaction dashboard, which also contains a set of 4 related reports, drills down on some of the reports to see the detail data. The BI user continues to view more dashboards – Customer Satisfaction and Service Request Overview, for example. After navigating through those dashboards, the user logs out of the application. The benchmark test is executed against a full production version of the Oracle Business Intelligence 11g Applications with a fully populated underlying database schema. The business processes in the test scenario closely represent a real world customer scenario. See Also SPARC T4-4 Server oracle.com OTN Oracle Business Intelligence oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN WebLogic Suite oracle.com OTN Oracle Solaris oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 30 September 2012.

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  • SQL SERVER – SSIS Parameters in Parent-Child ETL Architectures – Notes from the Field #040

    - by Pinal Dave
    [Notes from Pinal]: SSIS is very well explored subject, however, there are so many interesting elements when we read, we learn something new. A similar concept has been Parent-Child ETL architecture’s relationship in SSIS. Linchpin People are database coaches and wellness experts for a data driven world. In this 40th episode of the Notes from the Fields series database expert Tim Mitchell (partner at Linchpin People) shares very interesting conversation related to how to understand SSIS Parameters in Parent-Child ETL Architectures. In this brief Notes from the Field post, I will review the use of SSIS parameters in parent-child ETL architectures. A very common design pattern used in SQL Server Integration Services is one I call the parent-child pattern.  Simply put, this is a pattern in which packages are executed by other packages.  An ETL infrastructure built using small, single-purpose packages is very often easier to develop, debug, and troubleshoot than large, monolithic packages.  For a more in-depth look at parent-child architectures, check out my earlier blog post on this topic. When using the parent-child design pattern, you will frequently need to pass values from the calling (parent) package to the called (child) package.  In older versions of SSIS, this process was possible but not necessarily simple.  When using SSIS 2005 or 2008, or even when using SSIS 2012 or 2014 in package deployment mode, you would have to create package configurations to pass values from parent to child packages.  Package configurations, while effective, were not the easiest tool to work with.  Fortunately, starting with SSIS in SQL Server 2012, you can now use package parameters for this purpose. In the example I will use for this demonstration, I’ll create two packages: one intended for use as a child package, and the other configured to execute said child package.  In the parent package I’m going to build a for each loop container in SSIS, and use package parameters to pass in a value – specifically, a ClientID – for each iteration of the loop.  The child package will be executed from within the for each loop, and will create one output file for each client, with the source query and filename dependent on the ClientID received from the parent package. Configuring the Child and Parent Packages When you create a new package, you’ll see the Parameters tab at the package level.  Clicking over to that tab allows you to add, edit, or delete package parameters. As shown above, the sample package has two parameters.  Note that I’ve set the name, data type, and default value for each of these.  Also note the column entitled Required: this allows me to specify whether the parameter value is optional (the default behavior) or required for package execution.  In this example, I have one parameter that is required, and the other is not. Let’s shift over to the parent package briefly, and demonstrate how to supply values to these parameters in the child package.  Using the execute package task, you can easily map variable values in the parent package to parameters in the child package. The execute package task in the parent package, shown above, has the variable vThisClient from the parent package mapped to the pClientID parameter shown earlier in the child package.  Note that there is no value mapped to the child package parameter named pOutputFolder.  Since this parameter has the Required property set to False, we don’t have to specify a value for it, which will cause that parameter to use the default value we supplied when designing the child pacakge. The last step in the parent package is to create the for each loop container I mentioned earlier, and place the execute package task inside it.  I’m using an object variable to store the distinct client ID values, and I use that as the iterator for the loop (I describe how to do this more in depth here).  For each iteration of the loop, a different client ID value will be passed into the child package parameter. The final step is to configure the child package to actually do something meaningful with the parameter values passed into it.  In this case, I’ve modified the OleDB source query to use the pClientID value in the WHERE clause of the query to restrict results for each iteration to a single client’s data.  Additionally, I’ll use both the pClientID and pOutputFolder parameters to dynamically build the output filename. As shown, the pClientID is used in the WHERE clause, so we only get the current client’s invoices for each iteration of the loop. For the flat file connection, I’m setting the Connection String property using an expression that engages both of the parameters for this package, as shown above. Parting Thoughts There are many uses for package parameters beyond a simple parent-child design pattern.  For example, you can create standalone packages (those not intended to be used as a child package) and still use parameters.  Parameter values may be supplied to a package directly at runtime by a SQL Server Agent job, through the command line (via dtexec.exe), or through T-SQL. Also, you can also have project parameters as well as package parameters.  Project parameters work in much the same way as package parameters, but the parameters apply to all packages in a project, not just a single package. Conclusion Of the numerous advantages of using catalog deployment model in SSIS 2012 and beyond, package parameters are near the top of the list.  Parameters allow you to easily share values from parent to child packages, enabling more dynamic behavior and better code encapsulation. If you want me to take a look at your server and its settings, or if your server is facing any issue we can Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • Do Not Optimize Without Measuring

    - by Alois Kraus
    Recently I had to do some performance work which included reading a lot of code. It is fascinating with what ideas people come up to solve a problem. Especially when there is no problem. When you look at other peoples code you will not be able to tell if it is well performing or not by reading it. You need to execute it with some sort of tracing or even better under a profiler. The first rule of the performance club is not to think and then to optimize but to measure, think and then optimize. The second rule is to do this do this in a loop to prevent slipping in bad things for too long into your code base. If you skip for some reason the measure step and optimize directly it is like changing the wave function in quantum mechanics. This has no observable effect in our world since it does represent only a probability distribution of all possible values. In quantum mechanics you need to let the wave function collapse to a single value. A collapsed wave function has therefore not many but one distinct value. This is what we physicists call a measurement. If you optimize your application without measuring it you are just changing the probability distribution of your potential performance values. Which performance your application actually has is still unknown. You only know that it will be within a specific range with a certain probability. As usual there are unlikely values within your distribution like a startup time of 20 minutes which should only happen once in 100 000 years. 100 000 years are a very short time when the first customer tries your heavily distributed networking application to run over a slow WIFI network… What is the point of this? Every programmer/architect has a mental performance model in his head. A model has always a set of explicit preconditions and a lot more implicit assumptions baked into it. When the model is good it will help you to think of good designs but it can also be the source of problems. In real world systems not all assumptions of your performance model (implicit or explicit) hold true any longer. The only way to connect your performance model and the real world is to measure it. In the WIFI example the model did assume a low latency high bandwidth LAN connection. If this assumption becomes wrong the system did have a drastic change in startup time. Lets look at a example. Lets assume we want to cache some expensive UI resource like fonts objects. For this undertaking we do create a Cache class with the UI themes we want to support. Since Fonts are expensive objects we do create it on demand the first time the theme is requested. A simple example of a Theme cache might look like this: using System; using System.Collections.Generic; using System.Drawing; struct Theme { public Color Color; public Font Font; } static class ThemeCache { static Dictionary<string, Theme> _Cache = new Dictionary<string, Theme> { {"Default", new Theme { Color = Color.AliceBlue }}, {"Theme12", new Theme { Color = Color.Aqua }}, }; public static Theme Get(string theme) { Theme cached = _Cache[theme]; if (cached.Font == null) { Console.WriteLine("Creating new font"); cached.Font = new Font("Arial", 8); } return cached; } } class Program { static void Main(string[] args) { Theme item = ThemeCache.Get("Theme12"); item = ThemeCache.Get("Theme12"); } } This cache does create font objects only once since on first retrieve of the Theme object the font is added to the Theme object. When we let the application run it should print “Creating new font” only once. Right? Wrong! The vigilant readers have spotted the issue already. The creator of this cache class wanted to get maximum performance. So he decided that the Theme object should be a value type (struct) to not put too much pressure on the garbage collector. The code Theme cached = _Cache[theme]; if (cached.Font == null) { Console.WriteLine("Creating new font"); cached.Font = new Font("Arial", 8); } does work with a copy of the value stored in the dictionary. This means we do mutate a copy of the Theme object and return it to our caller. But the original Theme object in the dictionary will have always null for the Font field! The solution is to change the declaration of struct Theme to class Theme or to update the theme object in the dictionary. Our cache as it is currently is actually a non caching cache. The funny thing was that I found out with a profiler by looking at which objects where finalized. I found way too many font objects to be finalized. After a bit debugging I found the allocation source for Font objects was this cache. Since this cache was there for years it means that the cache was never needed since I found no perf issue due to the creation of font objects. the cache was never profiled if it did bring any performance gain. to make the cache beneficial it needs to be accessed much more often. That was the story of the non caching cache. Next time I will write something something about measuring.

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  • Cross-language Extension Method Calling

    - by Tom Hines
    Extension methods are a concise way of binding functions to particular types. In my last post, I showed how Extension methods can be created in the .NET 2.0 environment. In this post, I discuss calling the extensions from other languages. Most of the differences I find between the Dot Net languages are mainly syntax.  The declaration of Extensions is no exception.  There is, however, a distinct difference with the framework accepting excensions made with C++ that differs from C# and VB.  When calling the C++ extension from C#, the compiler will SOMETIMES say there is no definition for DoCPP with the error: 'string' does not contain a definition for 'DoCPP' and no extension method 'DoCPP' accepting a first argument of type 'string' could be found (are you missing a using directive or an assembly reference?) If I recompile, the error goes away. The strangest problem with calling the C++ extension from C# is that I first must make SOME type of reference to the class BEFORE using the extension or it will not be recognized at all.  So, if I first call the DoCPP() as a static method, the extension works fine later.  If I make a dummy instantiation of the class, it works.  If I have no forward reference of the class, I get the same error as before and recompiling does not fix it.  It seems as if this none of this is supposed to work across the languages. I have made a few work-arounds to get the examples to compile and run. Note the following examples: Extension in C# using System; namespace Extension_CS {    public static class CExtension_CS    {  //in C#, the "this" keyword is the key.       public static void DoCS(this string str)       {          Console.WriteLine("CS\t{0:G}\tCS", str);       }    } } Extension in C++ /****************************************************************************\  * Here is the C++ implementation.  It is the least elegant and most quirky,  * but it works. \****************************************************************************/ #pragma once using namespace System; using namespace System::Runtime::CompilerServices;     //<-Essential // Reference: System.Core.dll //<- Essential namespace Extension_CPP {        public ref class CExtension_CPP        {        public:               [Extension] // or [ExtensionAttribute] /* either works */               static void DoCPP(String^ str)               {                      Console::WriteLine("C++\t{0:G}\tC++", str);               }        }; } Extension in VB ' Here is the VB implementation.  This is not as elegant as the C#, but it's ' functional. Imports System.Runtime.CompilerServices ' Public Module modExtension_VB 'Extension methods can be defined only in modules.    <Extension()> _       Public Sub DoVB(ByVal str As String)       Console.WriteLine("VB" & Chr(9) & "{0:G}" & Chr(9) & "VB", str)    End Sub End Module   Calling program in C# /******************************************************************************\  * Main calling program  * Intellisense and VS2008 complain about the CPP implementation, but with a  * little duct-tape, it works just fine. \******************************************************************************/ using System; using Extension_CPP; using Extension_CS; using Extension_VB; // vitual namespace namespace TestExtensions {    public static class CTestExtensions    {       /**********************************************************************\        * For some reason, this needs a direct reference into the C++ version        * even though it does nothing than add a null reference.        * The constructor provides the fake usage to please the compiler.       \**********************************************************************/       private static CExtension_CPP x = null;   // <-DUCT_TAPE!       static CTestExtensions()       {          // Fake usage to stop compiler from complaining          if (null != x) {} // <-DUCT_TAPE       }       static void Main(string[] args)       {          string strData = "from C#";          strData.DoCPP();          strData.DoCS();          strData.DoVB();       }    } }   Calling program in VB  Imports Extension_CPP Imports Extension_CS Imports Extension_VB Imports System.Runtime.CompilerServices Module TestExtensions_VB    <Extension()> _       Public Sub DoCPP(ByVal str As String)       'Framework does not treat this as an extension, so use the static       CExtension_CPP.DoCPP(str)    End Sub    Sub Main()       Dim strData As String = "from VB"       strData.DoCS()       strData.DoVB()       strData.DoCPP() 'fake    End Sub End Module  Calling program in C++ // TestExtensions_CPP.cpp : main project file. #include "stdafx.h" using namespace System; using namespace Extension_CPP; using namespace Extension_CS; using namespace Extension_VB; void main(void) {        /*******************************************************\         * Extension methods are called like static methods         * when called from C++.  There may be a difference in         * syntax when calling the VB extension as VB Extensions         * are embedded in Modules instead of classes        \*******************************************************/     String^ strData = "from C++";     CExtension_CPP::DoCPP(strData);     CExtension_CS::DoCS(strData);     modExtension_VB::DoVB(strData); //since Extensions go in Modules }

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  • Dynamic Bursting ... no really!

    - by Tim Dexter
    If any of you have seen me or my colleagues present BI Publisher to you then we have hopefully mentioned 'bursting.' You may have even seen a demo where we talk about being able to take a batch of data, say invoices. Then split them by some criteria, say customer id; format them with a template; generate the output and then deliver the documents to the recipients with a click. We and especially I, always say this can be completely dynamic! By this I mean, that you could store customer preferences in a database. What layout would each customer like; what output format they would like and how they would like the document delivered. We (I) talk a good talk, but typically don't do the walk in a demo. We hard code everything in the bursting query or bursting control file to get the concept across. But no more peeps! I have finally put together a dynamic bursting demo! Its been minutes in the making but its been tough to find those minutes! Read on ... It's nothing amazing in terms of making the burst dynamic. I created a CUSTOMER_PREFS table with some simple UI in an APEX application so that I can maintain their requirements. In EBS you have descriptive flexfields that could do the same thing or probably even 'contact' fields to store most of the info. Here's my table structure: Name                           Type ------------------------------ -------- CUSTOMER_ID                    NUMBER(6) TEMPLATE_TYPE                  VARCHAR2(20) TEMPLATE_NAME                  VARCHAR2(120) OUTPUT_FORMAT                  VARCHAR2(20) DELIVERY_CHANNEL               VARCHAR2(50) EMAIL                          VARCHAR2(255) FAX                            VARCHAR2(20) ATTACH                         VARCHAR2(20) FILE_LOC                       VARCHAR2(255) Simple enough right? Just need CUSTOMER_ID as the key for the bursting engine to join it to the customer data at burst time. I have not covered the full delivery options, just email, fax and file location. Remember, its a demo people :0) However the principal is exactly the same for each delivery type. They each have a set of attributes that need to be provided and you will need to handle that in your bursting query. On a side note, in EBS, you use a bursting control file, you can apply the same principals that I'm laying out here you just need to get the customer bursting info into the XML data stream so that you can refer to it in the control file using XPATH expressions. Next, we need to look up what attributes or parameters are required for each delivery method. that can be found in the documentation here.  Now we know the combinations of parameters and delivery methods we can construct the query using a series a decode statements: select distinct cp.customer_id "KEY", cp.template_name TEMPLATE, cp.template_type TEMPLATE_FORMAT, 'en-US' LOCALE, cp.output_format OUTPUT_FORMAT, 'false' SAVE_FORMAT, cp.delivery_channel DEL_CHANNEL, decode(cp.delivery_channel,'FILE', cp.file_loc , 'EMAIL', cp.email , 'FAX', cp.fax) PARAMETER1, decode(cp.delivery_channel,'FILE', c.cust_last_name||'_orders.pdf' ,'EMAIL','[email protected]' ,'FAX', 'faxserver.com') PARAMETER2, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','[email protected]' ,'FAX', null) PARAMETER3, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','Your current orders' ,'FAX',NULL) PARAMETER4, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','Please find attached a copy of your current orders with BI Publisher, Inc' ,'FAX',NULL) PARAMETER5, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','false' ,'FAX',NULL) PARAMETER6, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','[email protected]' ,'FAX',NULL) PARAMETER7 from cust_prefs cp, customers c, orders_view ov where cp.customer_id = c.customer_id and cp.customer_id = ov.customer_id order by cp.customer_id Pretty straightforward, just need to test, test, test, the query and ensure it's bringing back the correct data based on each customers preferences. Notice the NULL values for parameters that are not relevant for a given delivery channel. You should end up with bursting control data that the bursting engine can use:  Now, your users can run the burst and documents will be formatted, generated and delivered based on the customer prefs. If you're interested in the example, I have used the sample OE schema data for the base report. The report files and CUST_PREFS table are zipped up here. The zip contains the data model (.xdmz), the report and templates (.xdoz) and the sql scripts to create and load data to the CUST_PREFS table.  Once you load the report into the catalog, you'll need to create the OE data connection and point the data model at it. You'll probably need to re-point the report to the data model too. Happy Bursting!

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  • Getting started with Oracle Database In-Memory Part III - Querying The IM Column Store

    - by Maria Colgan
    In my previous blog posts, I described how to install, enable, and populate the In-Memory column store (IM column store). This weeks post focuses on how data is accessed within the IM column store. Let’s take a simple query “What is the most expensive air-mail order we have received to date?” SELECT Max(lo_ordtotalprice) most_expensive_order FROM lineorderWHERE  lo_shipmode = 5; The LINEORDER table has been populated into the IM column store and since we have no alternative access paths (indexes or views) the execution plan for this query is a full table scan of the LINEORDER table. You will notice that the execution plan has a new set of keywords “IN MEMORY" in the access method description in the Operation column. These keywords indicate that the LINEORDER table has been marked for INMEMORY and we may use the IM column store in this query. What do I mean by “may use”? There are a small number of cases were we won’t use the IM column store even though the object has been marked INMEMORY. This is similar to how the keyword STORAGE is used on Exadata environments. You can confirm that the IM column store was actually used by examining the session level statistics, but more on that later. For now let's focus on how the data is accessed in the IM column store and why it’s faster to access the data in the new column format, for analytical queries, rather than the buffer cache. There are four main reasons why accessing the data in the IM column store is more efficient. 1. Access only the column data needed The IM column store only has to scan two columns – lo_shipmode and lo_ordtotalprice – to execute this query while the traditional row store or buffer cache has to scan all of the columns in each row of the LINEORDER table until it reaches both the lo_shipmode and the lo_ordtotalprice column. 2. Scan and filter data in it's compressed format When data is populated into the IM column it is automatically compressed using a new set of compression algorithms that allow WHERE clause predicates to be applied against the compressed formats. This means the volume of data scanned in the IM column store for our query will be far less than the same query in the buffer cache where it will scan the data in its uncompressed form, which could be 20X larger. 3. Prune out any unnecessary data within each column The fastest read you can execute is the read you don’t do. In the IM column store a further reduction in the amount of data accessed is possible due to the In-Memory Storage Indexes(IM storage indexes) that are automatically created and maintained on each of the columns in the IM column store. IM storage indexes allow data pruning to occur based on the filter predicates supplied in a SQL statement. An IM storage index keeps track of minimum and maximum values for each column in each of the In-Memory Compression Unit (IMCU). In our query the WHERE clause predicate is on the lo_shipmode column. The IM storage index on the lo_shipdate column is examined to determine if our specified column value 5 exist in any IMCU by comparing the value 5 to the minimum and maximum values maintained in the Storage Index. If the value 5 is outside the minimum and maximum range for an IMCU, the scan of that IMCU is avoided. For the IMCUs where the value 5 does fall within the min, max range, an additional level of data pruning is possible via the metadata dictionary created when dictionary-based compression is used on IMCU. The dictionary contains a list of the unique column values within the IMCU. Since we have an equality predicate we can easily determine if 5 is one of the distinct column values or not. The combination of the IM storage index and dictionary based pruning, enables us to only scan the necessary IMCUs. 4. Use SIMD to apply filter predicates For the IMCU that need to be scanned Oracle takes advantage of SIMD vector processing (Single Instruction processing Multiple Data values). Instead of evaluating each entry in the column one at a time, SIMD vector processing allows a set of column values to be evaluated together in a single CPU instruction. The column format used in the IM column store has been specifically designed to maximize the number of column entries that can be loaded into the vector registers on the CPU and evaluated in a single CPU instruction. SIMD vector processing enables the Oracle Database In-Memory to scan billion of rows per second per core versus the millions of rows per second per core scan rate that can be achieved in the buffer cache. I mentioned earlier in this post that in order to confirm the IM column store was used; we need to examine the session level statistics. You can monitor the session level statistics by querying the performance views v$mystat and v$statname. All of the statistics related to the In-Memory Column Store begin with IM. You can see the full list of these statistics by typing: display_name format a30 SELECT display_name FROM v$statname WHERE  display_name LIKE 'IM%'; If we check the session statistics after we execute our query the results would be as follow; SELECT Max(lo_ordtotalprice) most_expensive_order FROM lineorderWHERE lo_shipmode = 5; SELECT display_name FROM v$statname WHERE  display_name IN ('IM scan CUs columns accessed',                        'IM scan segments minmax eligible',                        'IM scan CUs pruned'); As you can see, only 2 IMCUs were accessed during the scan as the majority of the IMCUs (44) in the LINEORDER table were pruned out thanks to the storage index on the lo_shipmode column. In next weeks post I will describe how you can control which queries use the IM column store and which don't. +Maria Colgan

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  • Upgrading SSIS Custom Components for SQL Server 2012

    Having finally got around to upgrading my custom components to SQL Server 2012, I thought I’d share some notes on the process. One of the goals was minimal duplication, so the same code files are used to build the 2008 and 2012 components, I just have a separate project file. The high level steps are listed below, followed by some more details. Create a 2012 copy of the project file Upgrade project, just open the new project file is VS2010 Change target framework to .NET 4.0 Set conditional compilation symbol for DENALI Change any conditional code, including assembly version and UI type name Edit project file to change referenced assemblies for 2012 Change target framework to .NET 4.0 Open the project properties. On the Applications page, change the Target framework to .NET Framework 4. Set conditional compilation symbol for DENALI Re-open the project properties. On the Build tab, first change the Configuration to All Configurations, then set a Conditional compilation symbol of DENALI. Change any conditional code, including assembly version and UI type name The value doesn’t have to be DENALI, it can actually be anything you like, that is just what I use. It is how I control sections of code that vary between versions. There were several API changes between 2005 and 2008, as well as interface name changes. Whilst we don’t have the same issues between 2008 and 2012, I still have some sections of code that do change such as the assembly attributes. #if DENALI [assembly: AssemblyDescription("Data Generator Source for SQL Server Integration Services 2012")] [assembly: AssemblyCopyright("Copyright © 2012 Konesans Ltd")] [assembly: AssemblyVersion("3.0.0.0")] #else [assembly: AssemblyDescription("Data Generator Source for SQL Server Integration Services 2008")] [assembly: AssemblyCopyright("Copyright © 2008 Konesans Ltd")] [assembly: AssemblyVersion("2.0.0.0")] #endif The Visual Studio editor automatically formats the code based on the current compilation symbols, hence in this case the 2008 code is grey to indicate it is disabled. As you can see in the previous example I have distinct assembly version attributes, ensuring I can run both 2008 and 2012 versions of my component side by side. For custom components with a user interface, be sure to update the UITypeName property of the DtsTask or DtsPipelineComponent attributes. As above I use the conditional compilation symbol to control the code. #if DENALI [DtsTask ( DisplayName = "File Watcher Task", Description = "File Watcher Task", IconResource = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask.ico", UITypeName = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTaskUI,Konesans.Dts.Tasks.FileWatcherTask,Version=3.0.0.0,Culture=Neutral,PublicKeyToken=b2ab4a111192992b", TaskContact = "File Watcher Task; Konesans Ltd; Copyright © 2012 Konesans Ltd; http://www.konesans.com" )] #else [DtsTask ( DisplayName = "File Watcher Task", Description = "File Watcher Task", IconResource = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask.ico", UITypeName = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTaskUI,Konesans.Dts.Tasks.FileWatcherTask,Version=2.0.0.0,Culture=Neutral,PublicKeyToken=b2ab4a111192992b", TaskContact = "File Watcher Task; Konesans Ltd; Copyright © 2004-2008 Konesans Ltd; http://www.konesans.com" )] #endif public sealed class FileWatcherTask: Task, IDTSComponentPersist, IDTSBreakpointSite, IDTSSuspend { // .. code goes on... } Shown below is another example I found that needed changing. I borrow one of the MS editors, and use it against a custom property, but need to ensure I reference the correct version of the MS controls assembly. This section of code is actually shared between the 2005, 2008 and 2012 versions of my component hence it has test for both DENALI and KATMAI symbols. #if DENALI const string multiLineUI = "Microsoft.DataTransformationServices.Controls.ModalMultilineStringEditor, Microsoft.DataTransformationServices.Controls, Version=11.0.00.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; #elif KATMAI const string multiLineUI = "Microsoft.DataTransformationServices.Controls.ModalMultilineStringEditor, Microsoft.DataTransformationServices.Controls, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; #else const string multiLineUI = "Microsoft.DataTransformationServices.Controls.ModalMultilineStringEditor, Microsoft.DataTransformationServices.Controls, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; #endif // Create Match Expression parameter IDTSCustomPropertyCollection100 propertyCollection = outputColumn.CustomPropertyCollection; IDTSCustomProperty100 property = propertyCollection.New(); property = propertyCollection.New(); property.Name = MatchParams.Name; property.Description = MatchParams.Description; property.TypeConverter = typeof(MultilineStringConverter).AssemblyQualifiedName; property.UITypeEditor = multiLineUI; property.Value = MatchParams.DefaultValue; Edit project file to change referenced assemblies for 2012 We now need to edit the project file itself. Open the MyComponente2012.cproj  in you favourite text editor, and then perform a couple of find and replaces as listed below: Find Replace Comment Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Change the assembly references version from SQL Server 2008 to SQL Server 2012. Microsoft SQL Server\100\ Microsoft SQL Server\110\ Change any assembly reference hint path locations from from SQL Server 2008 to SQL Server 2012. If you use any Build Events during development, such as copying the component assembly to the DTS folder, or calling GACUTIL to install it into the GAC, you can also change these now. An example of my new post-build event for a pipeline component is shown below, which uses the .NET 4.0 path for GACUTIL. It also uses the 110 folder location, instead of 100 for SQL Server 2008, but that was covered the the previous find and replace. "C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools\gacutil.exe" /if "$(TargetPath)" copy "$(TargetPath)" "%ProgramFiles%\Microsoft SQL Server\110\DTS\PipelineComponents" /Y

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  • Breaking through the class sealing

    - by Jason Crease
    Do you understand 'sealing' in C#?  Somewhat?  Anyway, here's the lowdown. I've done this article from a C# perspective, but I've occasionally referenced .NET when appropriate. What is sealing a class? By sealing a class in C#, you ensure that you ensure that no class can be derived from that class.  You do this by simply adding the word 'sealed' to a class definition: public sealed class Dog {} Now writing something like " public sealed class Hamster: Dog {} " you'll get a compile error like this: 'Hamster: cannot derive from sealed type 'Dog' If you look in an IL disassembler, you'll see a definition like this: .class public auto ansi sealed beforefieldinit Dog extends [mscorlib]System.Object Note the addition of the word 'sealed'. What about sealing methods? You can also seal overriding methods.  By adding the word 'sealed', you ensure that the method cannot be overridden in a derived class.  Consider the following code: public class Dog : Mammal { public sealed override void Go() { } } public class Mammal { public virtual void Go() { } } In this code, the method 'Go' in Dog is sealed.  It cannot be overridden in a subclass.  Writing this would cause a compile error: public class Dachshund : Dog { public override void Go() { } } However, we can 'new' a method with the same name.  This is essentially a new method; distinct from the 'Go' in the subclass: public class Terrier : Dog { public new void Go() { } } Sealing properties? You can also seal seal properties.  You add 'sealed' to the property definition, like so: public sealed override string Name {     get { return m_Name; }     set { m_Name = value; } } In C#, you can only seal a property, not the underlying setters/getters.  This is because C# offers no override syntax for setters or getters.  However, in underlying IL you seal the setter and getter methods individually - a property is just metadata. Why bother sealing? There are a few traditional reasons to seal: Invariance. Other people may want to derive from your class, even though your implementation may make successful derivation near-impossible.  There may be twisted, hacky logic that could never be second-guessed by another developer.  By sealing your class, you're protecting them from wasting their time.  The CLR team has sealed most of the framework classes, and I assume they did this for this reason. Security.  By deriving from your type, an attacker may gain access to functionality that enables him to hack your system.  I consider this a very weak security precaution. Speed.  If a class is sealed, then .NET doesn't need to consult the virtual-function-call table to find the actual type, since it knows that no derived type can exist.  Therefore, it could emit a 'call' instead of 'callvirt' or at least optimise the machine code, thus producing a performance benefit.  But I've done trials, and have been unable to demonstrate this If you have an example, please share! All in all, I'm not convinced that sealing is interesting or important.  Anyway, moving-on... What is automatically sealed? Value types and structs.  If they were not always sealed, all sorts of things would go wrong.  For instance, structs are laid-out inline within a class.  But what if you assigned a substruct to a struct field of that class?  There may be too many fields to fit. Static classes.  Static classes exist in C# but not .NET.  The C# compiler compiles a static class into an 'abstract sealed' class.  So static classes are already sealed in C#. Enumerations.  The CLR does not track the types of enumerations - it treats them as simple value types.  Hence, polymorphism would not work. What cannot be sealed? Interfaces.  Interfaces exist to be implemented, so sealing to prevent implementation is dumb.  But what if you could prevent interfaces from being extended (i.e. ban declarations like "public interface IMyInterface : ISealedInterface")?  There is no good reason to seal an interface like this.  Sealing finalizes behaviour, but interfaces have no intrinsic behaviour to finalize Abstract classes.  In IL you can create an abstract sealed class.  But C# syntax for this already exists - declaring a class as a 'static', so it forces you to declare it as such. Non-override methods.  If a method isn't declared as override it cannot be overridden, so sealing would make no difference.  Note this is stated from a C# perspective - the words are opposite in IL.  In IL, you have four choices in total: no declaration (which actually seals the method), 'virtual' (called 'override' in C#), 'sealed virtual' ('sealed override' in C#) and 'newslot virtual' ('new virtual' or 'virtual' in C#, depending on whether the method already exists in a base class). Methods that implement interface methods.  Methods that implement an interface method must be virtual, so cannot be sealed. Fields.  A field cannot be overridden, only hidden (using the 'new' keyword in C#), so sealing would make no sense.

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  • Breaking up the Workday– Overcoming the Workaholic Syndrome

    - by dwahlin
    Hi, my name’s Dan Wahlin and I’m a workaholic – I admit it. It’s good from the standpoint that I get a lot done but it also has a lot of cons associated with it as well that I’m not proud of. I literally can’t watch TV without feeling like I should be doing something more productive (although I have no problem going to see movies at a theater or watching sporting events – that’s my escape I guess). On vacation it’s sometimes difficult the first few days to just “let go” of work and enjoy the time with my family. I always feel like I should be checking email and following up with different business projects. Fortunately, my wife knows me really well after 17 years of marriage and “gently” restricts my usage of laptops and other gadgets while we’re out. She also reminds me that constantly burying my face in gadgets just isn’t cool and shows a distinct lack of self control. On a given day I typically put in between 12 (at a minimum) up to 16-18 hours working on projects. My company does .NET consulting (ASP.NET/jQuery, SharePoint and Silverlight) but we also do a lot in the training space so there’s always a client project, some new courseware or some other deliverable that has to be worked on. My normal process for handling that is to just work my butt off and see how much I can get done. That process has worked well for a long time but when you start realizing that your happiness comes from how much work you accomplished that day then you have a problem. That’s especially true if you have kids (which I do….two awesome boys). It’s almost as if working more hours feels like I’m more successful or something which is of course ridiculous. It may actually mean that I’m too distracted or disorganized. Lately I’ve realized that while I’m still productive and always meet my deadlines, I’m really burnt out by the afternoon and have lost some of the excitement I used to have. Part of that’s normal I think given that I’ve been doing this for close to 15 years now, but in thinking through it more I realized that I just need to get away from the desk and take a break. By far, the happiest time of my life was my childhood. Part of that was due to having awesome parents, having far less responsibility (a big factor I suspect), being able to hang-out with friends at school, playing sports, games, etc. but I think a big part of the overall happiness came from being outside a lot. I lived on my bike as a little kid and as I grew up I shared time between riding an ATV all over the place, shooting hoops on the basketball court, playing golf and working on a golf course (all outside work of course).  Being a software developer and trainer I generally spend 95% or more of my day indoors and only see the sun when driving from place to place or by looking out the window (that’s sad because I live in a suburb of Phoenix, AZ where it’s nearly always sunny). I haven’t looked into any scientific studies on the matter, but I’d be willing to bet there’s a direct correlation between overall productivity/happiness and being outside some throughout the day (sunny or not). But, I wasn’t sure what to do about it since I do have a lot of deadlines I need to meet after all. While talking with my wife last night I mentioned how I feel like I’m in a rut and want to get the “fun” back that I used to have. She immediately said that I need to start making time for breaks (a real quick fact – she’s a lot smarter than me and nearly always right). Of course my first thought was that I’d be less productive taking breaks. If I spend 2 hours just relaxing then I’m losing 2 hours of work. But, I thought about it more and realized that I’m probably less productive when I work 10+ hours and only take less than 30 minutes for a lunch break to relax a little. I bet my brain is screaming, “Please let me relax a little so I can figure out these problems you’re trying to resolve!”. So, starting today I’m going to try to break the workaholic habit and spend time outside of the office. That could mean sitting around outside, working out, golfing, or whatever. I’ve decided that no gadgets are allowed during that time and that I shouldn’t work for more than 4 hours straight without taking a break. I have no idea how my little “break the workaholic syndrome” experiment will go or how long it will last, but I’d be very interested in hearing from others on how they keep fresh and focused without working yourself to death. If you have any specific ideas, techniques or practices you follow please share them. There’s a lot more to life than work and some of us (and I’m thinking of myself specifically) need to take a long, hard look at what kind of balance we currently have. I’d hate to look back at my life when I’m 80 years old and say, “The only thing I did was work – I missed out on life!”.

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  • PASS: 2013 Summit Location

    - by Bill Graziano
    HQ recently posted a brief update on our search for a location for 2013.  It includes links to posts by four Board members and two community members. I’d like to add my thoughts to the mix and ask you a question.  But I can’t give you a real understanding without telling you some history first. So far we’ve had the Summit in Chicago, San Francisco, Orlando, Dallas, Denver and Seattle.  Each has a little different feel and distinct memories.  I enjoyed getting drinks by the pool in Orlando after the sessions ended.  I didn’t like that our location in Dallas was so far away from all the nightlife.  Denver was in downtown but we had real challenges with hotels.  I enjoyed the different locations.  I always enjoyed the announcement during the third keynote with the location of the next Summit. There are two big events that impacted my thinking on the Summit location.  The first was our transition to the new management company in early 2007.  The event that September in Denver was put on with a six month planning cycle by a brand new headquarters staff.  It wasn’t perfect but came off much better than I had dared to hope.  It also moved us out of the cookie cutter conferences that we used to do into a model where we have a lot more control.  I think you’ll all agree that the production values of our last few Summits have been fantastic.  That Summit also led to our changing relationship with Microsoft.  Microsoft holds two seats on the PASS Board.  All the PASS Board members face the same challenge: we all have full-time jobs and PASS comes in second place professionally (or sometimes further back).  Starting in 2008 we were assigned a liaison from Microsoft that had a much larger block of time to coordinate with us.  That changed everything between PASS and Microsoft.  Suddenly we were talking to product marketing, Microsoft PR, their event team, the Tech*Ed team, the education division, their user group team and their field sales team – locally and internationally.  We strengthened our relationship with CSS, SQLCAT and the engineering teams.  We had exposure at the executive level that we’d never had before.  And their level of participation at the Summit changed from under 100 people to 400-500 people.  I think those 400+ Microsoft employees have value at a conference on Microsoft SQL Server.  For the first time, Seattle had a real competitive advantage over other cities. I’m one that looked very hard at staying in Seattle for a long, long time.  I think those Microsoft engineers have value to our attendees.  I think the increased support that Microsoft can provide when we’re in Seattle has value to our attendees.  But that doesn’t tell the whole story.  There’s a significant (and vocal!) percentage of our membership that wants the Summit outside Seattle.  Post-2007 PASS doesn’t know what it’s like to have a Summit outside of Seattle.  I think until we have a Summit in another city we won’t really know the trade-offs. I think a model where we move every third or every other year is interesting.  But until we have another Summit outside Seattle and we can evaluate the logistics and how important it is to have depth and variety in our Microsoft participation we won’t really know. Another benefit that comes with a move is variety or diversity.  I learn more when I’m exposed to new things and new people.  I believe that moving the Summit will give a different set of people an opportunity to attend. Grant Fritchey writes “It seems that the board is leaning, extremely heavily, towards making it a permanent fixture in Seattle.”  I don’t believe that’s true.  I know there was discussion of that earlier but I don’t believe it’s true now. And that brings me to my question.  Do we announce the city now or do we wait until the 2012 Summit?  I’m happy to announce Seattle vs. not-Seattle as soon as we sign the contract.  But I’d like to leave the actual city announcement until the 2011 Summit.  I like the drama and mystery of it.  I also like that it doesn’t give you a reason to skip a Summit and wait for the next one if it’s closer or back in Seattle.  The other side of the coin is that your planning is easier if you know where it is.  What do you think?

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  • Extending Database-as-a-Service to Provision Databases with Application Data

    - by Nilesh A
    Oracle Enterprise Manager 12c Database as a Service (DBaaS) empowers Self Service/SSA Users to rapidly spawn databases on demand in cloud. The configuration and structure of provisioned databases depends on respective service template selected by Self Service user while requesting for database. In EM12c, the DBaaS Self Service/SSA Administrator has the option of hosting various service templates in service catalog and based on underlying DBCA templates.Many times provisioned databases require production scale data either for UAT, testing or development purpose and managing DBCA templates with data can be unwieldy. So, we need to populate the database using post deployment script option and without any additional work for the SSA Users. The SSA Administrator can automate this task in few easy steps. For details on how to setup DBaaS Self Service Portal refer to the DBaaS CookbookIn this article, I will list steps required to enable EM 12c DBaaS to provision databases with application data in two distinct ways using: 1) Data pump 2) Transportable tablespaces (TTS). The steps listed below are just examples of how to extend EM 12c DBaaS and you can even have your own method plugged in part of post deployment script option. Using Data Pump to populate databases These are the steps to be followed to implement extending DBaaS using Data Pump methodolgy: Production DBA should run data pump export on the production database and make the dump file available to all the servers participating in the database zone [sample shown in Fig.1] -- Full exportexpdp FULL=y DUMPFILE=data_pump_dir:dpfull1%U.dmp, data_pump_dir:dpfull2%U.dmp PARALLEL=4 LOGFILE=data_pump_dir:dpexpfull.log JOB_NAME=dpexpfull Figure-1:  Full export of database using data pump Create a post deployment SQL script [sample shown in Fig. 2] and this script can either be uploaded into the software library by SSA Administrator or made available on a shared location accessible from servers where databases are likely to be provisioned Normal 0 -- Full importdeclare    h1   NUMBER;begin-- Creating the directory object where source database dump is backed up.    execute immediate 'create directory DEST_LOC as''/scratch/nagrawal/OracleHomes/oradata/INITCHNG/datafile''';-- Running import    h1 := dbms_datapump.open (operation => 'IMPORT', job_mode => 'FULL', job_name => 'DB_IMPORT10');    dbms_datapump.set_parallel(handle => h1, degree => 1);    dbms_datapump.add_file(handle => h1, filename => 'IMP_GRIDDB_FULL.LOG', directory => 'DATA_PUMP_DIR', filetype => 3);    dbms_datapump.add_file(handle => h1, filename => 'EXP_GRIDDB_FULL_%U.DMP', directory => 'DEST_LOC', filetype => 1);    dbms_datapump.start_job(handle => h1);    dbms_datapump.detach(handle => h1);end;/ Figure-2: Importing using data pump pl/sql procedures Using DBCA, create a template for the production database – include all the init.ora parameters, tablespaces, datafiles & their sizes SSA Administrator should customize “Create Database Deployment Procedure” and provide DBCA template created in the previous step. In “Additional Configuration Options” step of Customize “Create Database Deployment Procedure” flow, provide the name of the SQL script in the Custom Script section and lock the input (shown in Fig. 3). Continue saving the deployment procedure. Figure-3: Using Custom script option for calling Import SQL Now, an SSA user can login to Self Service Portal and use the flow to provision a database that will also  populate the data using the post deployment step. Using Transportable tablespaces to populate databases Copy of all user/application tablespaces will enable this method of populating databases. These are the required steps to extend DBaaS using transportable tablespaces: Production DBA needs to create a backup of tablespaces. Datafiles may need conversion [such as from Big Endian to Little Endian or vice versa] based on the platform of production and destination where DBaaS created the test database. Here is sample backup script shows how to find out if any conversion is required, describes the steps required to convert datafiles and backup tablespace. SSA Administrator should copy the database (tablespaces) backup datafiles and export dumps to the backup location accessible from the hosts participating in the database zone(s). Create a post deployment SQL script and this script can either be uploaded into the software library by SSA Administrator or made available on a shared location accessible from servers where databases are likely to be provisioned. Here is sample post deployment SQL script using transportable tablespaces. Using DBCA, create a template for the production database – all the init.ora parameters should be included. NOTE: DO NOT choose to bring tablespace data into this template as they will be created SSA Administrator should customize “Create Database Deployment Procedure” and provide DBCA template created in the previous step. In the “Additional Configuration Options” step of the flow, provide the name of the SQL script in the Custom Script section and lock the input. Continue saving the deployment procedure. Now, an SSA user can login to Self Service Portal and use the flow to provision a database that will also populate the data using the post deployment step. More Information: Database-as-a-Service on Exadata Cloud Podcast on Database as a Service using Oracle Enterprise Manager 12c Oracle Enterprise Manager 12c Installation and Administration guide, Cloud Administration guide DBaaS Cookbook Screenwatch: Private Database Cloud: Set Up the Cloud Self-Service Portal Screenwatch: Private Database Cloud: Use the Cloud Self-Service Portal Stay Connected: Twitter |  Face book |  You Tube |  Linked in |  Newsletter

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  • ROracle support for TimesTen In-Memory Database

    - by Sam Drake
    Today's guest post comes from Jason Feldhaus, a Consulting Member of Technical Staff in the TimesTen Database organization at Oracle.  He shares with us a sample session using ROracle with the TimesTen In-Memory database.  Beginning in version 1.1-4, ROracle includes support for the Oracle Times Ten In-Memory Database, version 11.2.2. TimesTen is a relational database providing very fast and high throughput through its memory-centric architecture.  TimesTen is designed for low latency, high-volume data, and event and transaction management. A TimesTen database resides entirely in memory, so no disk I/O is required for transactions and query operations. TimesTen is used in applications requiring very fast and predictable response time, such as real-time financial services trading applications and large web applications. TimesTen can be used as the database of record or as a relational cache database to Oracle Database. ROracle provides an interface between R and the database, providing the rich functionality of the R statistical programming environment using the SQL query language. ROracle uses the OCI libraries to handle database connections, providing much better performance than standard ODBC.The latest ROracle enhancements include: Support for Oracle TimesTen In-Memory Database Support for Date-Time using R's POSIXct/POSIXlt data types RAW, BLOB and BFILE data type support Option to specify number of rows per fetch operation Option to prefetch LOB data Break support using Ctrl-C Statement caching support Times Ten 11.2.2 contains enhanced support for analytics workloads and complex queries: Analytic functions: AVG, SUM, COUNT, MAX, MIN, DENSE_RANK, RANK, ROW_NUMBER, FIRST_VALUE and LAST_VALUE Analytic clauses: OVER PARTITION BY and OVER ORDER BY Multidimensional grouping operators: Grouping clauses: GROUP BY CUBE, GROUP BY ROLLUP, GROUP BY GROUPING SETS Grouping functions: GROUP, GROUPING_ID, GROUP_ID WITH clause, which allows repeated references to a named subquery block Aggregate expressions over DISTINCT expressions General expressions that return a character string in the source or a pattern within the LIKE predicate Ability to order nulls first or last in a sort result (NULLS FIRST or NULLS LAST in the ORDER BY clause) Note: Some functionality is only available with Oracle Exalytics, refer to the TimesTen product licensing document for details. Connecting to TimesTen is easy with ROracle. Simply install and load the ROracle package and load the driver. > install.packages("ROracle") > library(ROracle) Loading required package: DBI > drv <- dbDriver("Oracle") Once the ROracle package is installed, create a database connection object and connect to a TimesTen direct driver DSN as the OS user. > conn <- dbConnect(drv, username ="", password="", dbname = "localhost/SampleDb_1122:timesten_direct") You have the option to report the server type - Oracle or TimesTen? > print (paste ("Server type =", dbGetInfo (conn)$serverType)) [1] "Server type = TimesTen IMDB" To create tables in the database using R data frame objects, use the function dbWriteTable. In the following example we write the built-in iris data frame to TimesTen. The iris data set is a small example data set containing 150 rows and 5 columns. We include it here not to highlight performance, but so users can easily run this example in their R session. > dbWriteTable (conn, "IRIS", iris, overwrite=TRUE, ora.number=FALSE) [1] TRUE Verify that the newly created IRIS table is available in the database. To list the available tables and table columns in the database, use dbListTables and dbListFields, respectively. > dbListTables (conn) [1] "IRIS" > dbListFields (conn, "IRIS") [1] "SEPAL.LENGTH" "SEPAL.WIDTH" "PETAL.LENGTH" "PETAL.WIDTH" "SPECIES" To retrieve a summary of the data from the database we need to save the results to a local object. The following call saves the results of the query as a local R object, iris.summary. The ROracle function dbGetQuery is used to execute an arbitrary SQL statement against the database. When connected to TimesTen, the SQL statement is processed completely within main memory for the fastest response time. > iris.summary <- dbGetQuery(conn, 'SELECT SPECIES, AVG ("SEPAL.LENGTH") AS AVG_SLENGTH, AVG ("SEPAL.WIDTH") AS AVG_SWIDTH, AVG ("PETAL.LENGTH") AS AVG_PLENGTH, AVG ("PETAL.WIDTH") AS AVG_PWIDTH FROM IRIS GROUP BY ROLLUP (SPECIES)') > iris.summary SPECIES AVG_SLENGTH AVG_SWIDTH AVG_PLENGTH AVG_PWIDTH 1 setosa 5.006000 3.428000 1.462 0.246000 2 versicolor 5.936000 2.770000 4.260 1.326000 3 virginica 6.588000 2.974000 5.552 2.026000 4 <NA> 5.843333 3.057333 3.758 1.199333 Finally, disconnect from the TimesTen Database. > dbCommit (conn) [1] TRUE > dbDisconnect (conn) [1] TRUE We encourage you download Oracle software for evaluation from the Oracle Technology Network. See these links for our software: Times Ten In-Memory Database,  ROracle.  As always, we welcome comments and questions on the TimesTen and  Oracle R technical forums.

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  • Modularity through HTTP

    - by Michael Williamson
    As programmers, we strive for modularity in the code we write. We hope that splitting the problem up makes it easier to solve, and allows us to reuse parts of our code in other applications. Object-orientation is the most obvious of many attempts to get us closer to this ideal, and yet one of the most successful approaches is almost accidental: the web. Programming languages provide us with functions and classes, and plenty of other ways to modularize our code. This allows us to take our large problem, split it into small parts, and solve those small parts without having to worry about the whole. It also makes it easier to reason about our code. So far, so good, but now that we’ve written our small, independent module, for example to send out e-mails to my customers, we’d like to reuse it in another application. By creating DLLs, JARs or our platform’s package container of choice, we can do just that – provided our new application is on the same platform. Want to use a Java library from C#? Well, good luck – it might be possible, but it’s not going to be smooth sailing. Even if a library exists, it doesn’t mean that using it going to be a pleasant experience. Say I want to use Java to write out an XML document to an output stream. You’d imagine this would be a simple one-liner. You’d be wrong: import org.w3c.dom.*; import java.io.*; import javax.xml.transform.*; import javax.xml.transform.dom.*; import javax.xml.transform.stream.*; private static final void writeDoc(Document doc, OutputStream out) throws IOException { try { Transformer t = TransformerFactory.newInstance().newTransformer(); t.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId()); t.transform(new DOMSource(doc), new StreamResult(out)); } catch (TransformerException e) { throw new AssertionError(e); // Can't happen! } } Most of the time, there is a good chance somebody else has written the code before, but if nobody can understand the interface to that code, nobody’s going to use it. The result is that most of the code we write is just a variation on a theme. Despite our best efforts, we’ve fallen a little short of our ideal, but the web brings us closer. If we want to send e-mails to our customers, we could write an e-mail-sending library. More likely, we’d use an existing one for our language. Even then, we probably wouldn’t have niceties like A/B testing or DKIM signing. Alternatively, we could just fire some HTTP requests at MailChimp, and get a whole slew of features without getting anywhere near the code that implements them. The web is inherently language agnostic. So long as your language can send and receive text over HTTP, and probably parse some JSON, you’re about as well equipped as anybody. Instead of building libraries for a specific language, we can build a service that almost every language can reuse. The text-based nature of HTTP also helps to limit the complexity of the API. As SOAP will attest, you can still make a horrible mess using HTTP, but at least it is an obvious horrible mess. Complex data structures are tedious to marshal to and from text, providing a strong incentive to keep things simple. By contrast, spotting the complexities in a class hierarchy is often not as easy. HTTP doesn’t solve every problem. It probably isn’t such a good idea to use it inside an inner loop that’s executed thousands of times per second. What’s more, the HTTP approach might introduce some new problems. We often need to add a thin shim to each application that we wish to communicate over HTTP. For instance, we might need to write a small plugin in PHP if we want to integrate WordPress into our system. Suddenly, instead of a system written in one language, we’re maintaining a system with several distinct languages and platforms. Even then, we should strive to avoid re-implementing the same old thing. As programmers, we consistently underestimate both the cost of building a system and the ongoing maintenance. If we allow ourselves to integrate existing applications, even if they’re in unfamiliar languages, we save ourselves those development and maintenance costs, as well as being able to pick the best solution for our problem. Thanks to the web, HTTP is often the easiest way to get there.

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  • Computer Networks UNISA - Chap 8 &ndash; Wireless Networking

    - by MarkPearl
    After reading this section you should be able to Explain how nodes exchange wireless signals Identify potential obstacles to successful transmission and their repercussions, such as interference and reflection Understand WLAN architecture Specify the characteristics of popular WLAN transmission methods including 802.11 a/b/g/n Install and configure wireless access points and their clients Describe wireless MAN and WAN technologies, including 802.16 and satellite communications The Wireless Spectrum All wireless signals are carried through the air by electromagnetic waves. The wireless spectrum is a continuum of the electromagnetic waves used for data and voice communication. The wireless spectrum falls between 9KHZ and 300 GHZ. Characteristics of Wireless Transmission Antennas Each type of wireless service requires an antenna specifically designed for that service. The service’s specification determine the antenna’s power output, frequency, and radiation pattern. A directional antenna issues wireless signals along a single direction. An omnidirectional antenna issues and receives wireless signals with equal strength and clarity in all directions The geographical area that an antenna or wireless system can reach is known as its range Signal Propagation LOS (line of sight) uses the least amount of energy and results in the reception of the clearest possible signal. When there is an obstacle in the way, the signal may… pass through the object or be obsrobed by the object or may be subject to reflection, diffraction or scattering. Reflection – waves encounter an object and bounces off it. Diffraction – signal splits into secondary waves when it encounters an obstruction Scattering – is the diffusion or the reflection in multiple different directions of a signal Signal Degradation Fading occurs as a signal hits various objects. Because of fading, the strength of the signal that reaches the receiver is lower than the transmitted signal strength. The further a signal moves from its source, the weaker it gets (this is called attenuation) Signals are also affected by noise – the electromagnetic interference) Interference can distort and weaken a wireless signal in the same way that noise distorts and weakens a wired signal. Frequency Ranges Older wireless devices used the 2.4 GHZ band to send and receive signals. This had 11 communication channels that are unlicensed. Newer wireless devices can also use the 5 GHZ band which has 24 unlicensed bands Narrowband, Broadband, and Spread Spectrum Signals Narrowband – a transmitter concentrates the signal energy at a single frequency or in a very small range of frequencies Broadband – uses a relatively wide band of the wireless spectrum and offers higher throughputs than narrowband technologies The use of multiple frequencies to transmit a signal is known as spread-spectrum technology. In other words a signal never stays continuously within one frequency range during its transmission. One specific implementation of spread spectrum is FHSS (frequency hoping spread spectrum). Another type is known as DSS (direct sequence spread spectrum) Fixed vs. Mobile Each type of wireless communication falls into one of two categories Fixed – the location of the transmitted and receiver do not move (results in energy saved because weaker signal strength is possible with directional antennas) Mobile – the location can change WLAN (Wireless LAN) Architecture There are two main types of arrangements Adhoc – data is sent directly between devices – good for small local devices Infrastructure mode – a wireless access point is placed centrally, that all devices connect with 802.11 WLANs The most popular wireless standards used on contemporary LANs are those developed by IEEE’s 802.11 committee. Over the years several distinct standards related to wireless networking have been released. Four of the best known standards are also referred to as Wi-Fi. They are…. 802.11b 802.11a 802.11g 802.11n These four standards share many characteristics. i.e. All 4 use half duplex signalling Follow the same access method Access Method 802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) to access a shared medium. Using CSMA/CA before a station begins to send data on an 802.11 network, it checks for existing wireless transmissions. If the source node detects no transmission activity on the network, it waits a brief period of time and then sends its transmission. If the source does detect activity, it waits a brief period of time before checking again. The destination node receives the transmission and, after verifying its accuracy, issues an acknowledgement (ACT) packet to the source. If the source receives the ACK it assumes the transmission was successful, – if it does not receive an ACK it assumes the transmission failed and sends it again. Association Two types of scanning… Active – station transmits a special frame, known as a prove, on all available channels within its frequency range. When an access point finds the probe frame, it issues a probe response. Passive – wireless station listens on all channels within its frequency range for a special signal, known as a beacon frame, issued from an access point – the beacon frame contains information necessary to connect to the point. Re-association occurs when a mobile user moves out of one access point’s range and into the range of another. Frames Read page 378 – 381 about frames and specific 802.11 protocols Bluetooth Networks Sony Ericson originally invented the Bluetooth technology in the early 1990s. In 1998 other manufacturers joined Ericsson in the Special Interest Group (SIG) whose aim was to refine and standardize the technology. Bluetooth was designed to be used on small networks composed of personal communications devices. It has become popular wireless technology for communicating among cellular telephones, phone headsets, etc. Wireless WANs and Internet Access Refer to pages 396 – 402 of the textbook for details.

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  • ROracle support for TimesTen In-Memory Database

    - by Sherry LaMonica
    Today's guest post comes from Jason Feldhaus, a Consulting Member of Technical Staff in the TimesTen Database organization at Oracle.  He shares with us a sample session using ROracle with the TimesTen In-Memory database.  Beginning in version 1.1-4, ROracle includes support for the Oracle Times Ten In-Memory Database, version 11.2.2. TimesTen is a relational database providing very fast and high throughput through its memory-centric architecture.  TimesTen is designed for low latency, high-volume data, and event and transaction management. A TimesTen database resides entirely in memory, so no disk I/O is required for transactions and query operations. TimesTen is used in applications requiring very fast and predictable response time, such as real-time financial services trading applications and large web applications. TimesTen can be used as the database of record or as a relational cache database to Oracle Database. ROracle provides an interface between R and the database, providing the rich functionality of the R statistical programming environment using the SQL query language. ROracle uses the OCI libraries to handle database connections, providing much better performance than standard ODBC.The latest ROracle enhancements include: Support for Oracle TimesTen In-Memory Database Support for Date-Time using R's POSIXct/POSIXlt data types RAW, BLOB and BFILE data type support Option to specify number of rows per fetch operation Option to prefetch LOB data Break support using Ctrl-C Statement caching support Times Ten 11.2.2 contains enhanced support for analytics workloads and complex queries: Analytic functions: AVG, SUM, COUNT, MAX, MIN, DENSE_RANK, RANK, ROW_NUMBER, FIRST_VALUE and LAST_VALUE Analytic clauses: OVER PARTITION BY and OVER ORDER BY Multidimensional grouping operators: Grouping clauses: GROUP BY CUBE, GROUP BY ROLLUP, GROUP BY GROUPING SETS Grouping functions: GROUP, GROUPING_ID, GROUP_ID WITH clause, which allows repeated references to a named subquery block Aggregate expressions over DISTINCT expressions General expressions that return a character string in the source or a pattern within the LIKE predicate Ability to order nulls first or last in a sort result (NULLS FIRST or NULLS LAST in the ORDER BY clause) Note: Some functionality is only available with Oracle Exalytics, refer to the TimesTen product licensing document for details. Connecting to TimesTen is easy with ROracle. Simply install and load the ROracle package and load the driver. > install.packages("ROracle") > library(ROracle) Loading required package: DBI > drv <- dbDriver("Oracle") Once the ROracle package is installed, create a database connection object and connect to a TimesTen direct driver DSN as the OS user. > conn <- dbConnect(drv, username ="", password="", dbname = "localhost/SampleDb_1122:timesten_direct") You have the option to report the server type - Oracle or TimesTen? > print (paste ("Server type =", dbGetInfo (conn)$serverType)) [1] "Server type = TimesTen IMDB" To create tables in the database using R data frame objects, use the function dbWriteTable. In the following example we write the built-in iris data frame to TimesTen. The iris data set is a small example data set containing 150 rows and 5 columns. We include it here not to highlight performance, but so users can easily run this example in their R session. > dbWriteTable (conn, "IRIS", iris, overwrite=TRUE, ora.number=FALSE) [1] TRUE Verify that the newly created IRIS table is available in the database. To list the available tables and table columns in the database, use dbListTables and dbListFields, respectively. > dbListTables (conn) [1] "IRIS" > dbListFields (conn, "IRIS") [1] "SEPAL.LENGTH" "SEPAL.WIDTH" "PETAL.LENGTH" "PETAL.WIDTH" "SPECIES" To retrieve a summary of the data from the database we need to save the results to a local object. The following call saves the results of the query as a local R object, iris.summary. The ROracle function dbGetQuery is used to execute an arbitrary SQL statement against the database. When connected to TimesTen, the SQL statement is processed completely within main memory for the fastest response time. > iris.summary <- dbGetQuery(conn, 'SELECT SPECIES, AVG ("SEPAL.LENGTH") AS AVG_SLENGTH, AVG ("SEPAL.WIDTH") AS AVG_SWIDTH, AVG ("PETAL.LENGTH") AS AVG_PLENGTH, AVG ("PETAL.WIDTH") AS AVG_PWIDTH FROM IRIS GROUP BY ROLLUP (SPECIES)') > iris.summary SPECIES AVG_SLENGTH AVG_SWIDTH AVG_PLENGTH AVG_PWIDTH 1 setosa 5.006000 3.428000 1.462 0.246000 2 versicolor 5.936000 2.770000 4.260 1.326000 3 virginica 6.588000 2.974000 5.552 2.026000 4 <NA> 5.843333 3.057333 3.758 1.199333 Finally, disconnect from the TimesTen Database. > dbCommit (conn) [1] TRUE > dbDisconnect (conn) [1] TRUE We encourage you download Oracle software for evaluation from the Oracle Technology Network. See these links for our software: Times Ten In-Memory Database,  ROracle.  As always, we welcome comments and questions on the TimesTen and  Oracle R technical forums.

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  • "Guiding" a Domain Expert to Retire from Programming

    - by James Kolpack
    I've got a friend who does IT at a local non-profit where they're using a custom web application which is no longer supported by the company who built it. (out of business, support was too expensive, I'm not sure...) Development on this app started around 10+ years ago so the technologies being harnessed are pretty out of date now - classic asp using vbscript and SQL Server 2000. The application domain is in the realm of government bookkeeping - so even though the development team is long gone, there are often new requirements of this software. Enter the... The domain expert. This is an middle aged accounting whiz without much (or any?) prior development experience. He studied the pages, code and queries and learned how to ape the style of the original team which, believe me, is mediocre at best. He's very clever and very tenacious but has no experience in software beyond what he's picked up from this app. Otherwise, he's a pleasant guy to talk to and definitely knows his domain. My friend in IT, and probably his superiors in the company, want him out of the code. They view him as wasting his expertise on coding tasks he shouldn't be doing. My friend got me involved with a few small contracts which I handled without much problem - other than somewhat of a communication barrier with the domain expert. He explained the requirements very quickly, assuming prior knowledge of the domain which I do not have. This is partially his normal style, and I think maybe a bit of resentment from my involvement. So, I think he feels like the owner of the code and has entrenched himself in a development position. So... his coding technique. One of his latest endeavors was to make a page that only he could reach (theoretically - the security model for the system is wretched) where he can enter a raw SQL query, run it, and save the query to run again later. A report that I worked on had been originally implemented by him using 6 distinct queries, 3 or 4 temp tables to coordinate the data between the queries, and the final result obtained by importing the data from the final query into Access and doing a pivot and some formatting. It worked - well, some of the results were incorrect - but at what a cost! (I implemented the report in a single query with at least 1/10th the amount of code.) He edits code in notepad. He doesn't seem to know about online reference material for the languages. I recently read an article on Dr. Dobbs titled "What Makes Bad Programmers Different" - and instantly thought of our domain expert. From the article: Their code is large, messy, and bug laden. They have very superficial knowledge of their problem domain and their tools. Their code has a lot of copy/paste and they have very little interest in techniques that reduce it. The fail to account for edge cases, while inefficiently dealing with the general case. They never have time to comment their code or break it into smaller pieces. Empirical evidence plays no little role in their decisions. 5.5 out of 6. My friend is wanting me to argue the case to their management - specifically, I got this email from their manager to respond to: ...Also, I need to talk to you about what effect there is from Domain Expert continuing to make edits to the live environment. If that is a problem for you I need to know so I can have his access blocked. Some examples would help. In my opinion, from a technical standpoint, it's dangerous to have him making changes without any oversight. On the other hand, I'm just doing one-off contracts at this point and don't have much desire to get involved deeply enough that I'm essentially arguing as one of the Bobs from Office Space. I'd like to help my friend out - but I feel like I'm getting in the middle of a political battle. More importantly - if I do get involved and suggest that his editing privileges be removed, it needs to be handled carefully so that doesn't feel belittled. He is beyond a doubt the foremost expert on this system. I'm hoping this is familiar territory for some other stackechangers, because I'm feeling a little bewildered. How should I respond? Should I argue that he shouldn't be allowed to touch the code? Should I phrase it as "no single developer, no matter how experienced, should be working on production code unchecked"? Should I argue to keep him involved with the code, but with a review process? Should I say "glad I could help, but uh, I'm busy now!" Other options? Thanks a bunch!

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  • DataBinding: 'System.String' does not contain a property with the name 'dbMake'.

    - by marcmiki
    Hi , i am a newbie at ASP.net and after using sqldatasource with a listview to insert and show results from an SQL server db i want to try using the LINQ datasource since it seems to be more flexible in codebehind. My problem is this: i droped a listview control to the page and i created the Linq datasource in codebehind with vb. the issue that i am having when i ..Select d.columms name i get the error system.string does not contain a property with the name "columname".. if i ommit the column name then its works fine.. the funny part is the d.count works fine but after that i get the error.. please see my code below: vb code Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Dim rowsCount As Integer Dim showSearchForm As String showSearchForm = Request.QueryString("tab") If showSearchForm = "1" Then Dim db As New ASPNETDBDataContext() Dim q = From b In db.PassengerVehiclesTables Select b.dbMake rowsCount = q.Count MsgBox(rowsCount) lvMakes.DataSource = q lvMakes.DataBind() PnlPassengerVehiclesSearch.Visible = True ElseIf showSearchForm = "2" Then aspx code <asp:Panel ID="PnlPassengerVehiclesSearch" Visible="false" runat="server"> Search Passenger Vehicles Form.....<br /> <table style="width: 100%; border-style: solid; border-width: 1px"> <tr> <td> <asp:ListView ID="lvMakes" runat="server"> <LayoutTemplate> <asp:PlaceHolder runat="server" ID="itemPlaceholder" /> </LayoutTemplate> <ItemTemplate> <%#Eval("dbMake")%><br /> </ItemTemplate> </asp:ListView> </td> b.dbMake needs to work so that i can use Distinct ,, ia m using asp.net version:3.5 and IIS version 7.0 .. not sure what i am missing ,, but i did try alot of approaches,,1- checked the web.config file and it seems to have two assemblies and two namespaces for LINQ..2- used different databinding syntaxs,,and i searched a lot for the solution.. the last one i read the person ommited the name of the column,, i thought that wasnt the best solution.. also my dbMake column is comming up in the "intellisence" .. thank you in advance for your help..

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  • TFS and shared projects in multiple solutions

    - by David Stratton
    Our .NET team works on projects for our company that fall into distinct categories. Some are internal web apps, some are external (publicly facing) web apps, we also have internal Windows applications for our corporate office users, and Windows Forms apps for our retail locations (stores). Of course, because we hate code reuse, we have a ton of code that is shared among the different applications. Currently we're using SVN as our source control, and we've got our repository laid out like this: - = folder, | = Visual Studio Solution -SVN - Internet | Ourcompany.com | Oursecondcompany.com - Intranet | UniformOrdering website | MessageCenter website - Shared | ErrorLoggingModule | RegularExpressionGenerator | Anti-Xss | OrgChartModule etc... So.. The OurCompany.com solution in the Internet folder would have a website project, and it would also include the ErrorLoggingModule, RegularExpressionGenerator, and Anti-Xss projects from the shared directory. Similarly, our UniformOrdering website solution would have each of these projects included in the solution as well. We prefer to have a project reference to a .dll reference because, first of all, if we need to add or fix a function in the ErrorLoggingModule while working on the OurCompany.com website, it's right there. Also, this allows us to build each solution and see if changes to shared code break any other applications. This should work well on a build server as well if I'm correct. In SVN, there is no problem with this. SVN and Visual Studio aren't tied together in the way TFS's source control is. We never figured out how to work this type of structure in TFS when we were using it, because in TFS, the TFS project was always tied to a Visual Studio Solution. The Source Code repository was a child of the TFS Project, so if we wanted to do this, we had to duplicate the Shared code in each TFS project's source code repository. As my co-worker put it, this "breaks every known best practice about code reuse and simplicity". It was enough of a deal breaker for us that we switched to SVN. Now, however, we're faced with truly fixing our development processes, and the Application Lifecycle Management of TFS is pretty close to exactly what we want, and how we want to work. Our one sticking point is the shared code issue. We're evaluating other commercial and open source solutions, but since we're already paying for TFS with our MSDN Subscriptions, and TFS is pretty much exactly what we want, we'd REALLY like to find a way around this issue. Has anybody else faced this and come up with a solution? If you've seen an article or posting on this that you can share with me, that would help as well. As always, I'm open to answers like "You're looking at it all wrong, bonehead, HERE'S the way it SHOULD be done.

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  • Prevent recursive CTE visiting nodes multiple times

    - by bacar
    Consider the following simple DAG: 1->2->3->4 And a table, #bar, describing this (I'm using SQL Server 2005): parent_id child_id 1 2 2 3 3 4 //... other edges, not connected to the subgraph above Now imagine that I have some other arbitrary criteria that select the first and last edges, i.e. 1-2 and 3-4. I want to use these to find the rest of my graph. I can write a recursive CTE as follows (I'm using terminology from MSDN): with foo(parent_id,child_id) as ( // anchor member that happens to select first and last edges: select parent_id,child_id from #bar where parent_id in (1,3) union all // recursive member: select #bar.* from #bar join foo on #bar.parent_id = foo.child_id ) select parent_id,child_id from foo However, this results in edge 3-4 being selected twice: parent_id child_id 1 2 3 4 2 3 3 4 // 2nd appearance! How can I prevent the query from recursing into subgraphs that have already been described? I could achieve this if, in my "recursive member" part of the query, I could reference all data that has been retrieved by the recursive CTE so far (and supply a predicate indicating in the recursive member excluding nodes already visited). However, I think I can access data that was returned by the last iteration of the recursive member only. This will not scale well when there is a lot of such repetition. Is there a way of preventing this unnecessary additional recursion? Note that I could use "select distinct" in the last line of my statement to achieve the desired results, but this seems to be applied after all the (repeated) recursion is done, so I don't think this is an ideal solution. Edit - hainstech suggests stopping recursion by adding a predicate to exclude recursing down paths that were explicitly in the starting set, i.e. recurse only where foo.child_id not in (1,3). That works for the case above only because it simple - all the repeated sections begin within the anchor set of nodes. It doesn't solve the general case where they may not be. e.g., consider adding edges 1-4 and 4-5 to the above set. Edge 4-5 will be captured twice, even with the suggested predicate. :(

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  • getting rid of filesort on WordPress MySQL query

    - by Hans
    An instance of WordPress that I manage goes down about once a day due to this monster MySQL query taking far too long: SELECT SQL_CALC_FOUND_ROWS distinct wp_posts.* FROM wp_posts LEFT JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy ON wp_term_taxonomy.term_taxonomy_id = wp_term_relationships.term_taxonomy_id LEFT JOIN wp_ec3_schedule ec3_sch ON ec3_sch.post_id=id WHERE 1=1 AND wp_posts.ID NOT IN ( SELECT tr.object_id FROM wp_term_relationships AS tr INNER JOIN wp_term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy = 'category' AND tt.term_id IN ('1050') ) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish') AND NOT EXISTS (SELECT * FROM wp_term_relationships JOIN wp_term_taxonomy ON wp_term_taxonomy.term_taxonomy_id = wp_term_relationships.term_taxonomy_id WHERE wp_term_relationships.object_id = wp_posts.ID AND wp_term_taxonomy.taxonomy = 'category' AND wp_term_taxonomy.term_id IN (533,3567) ) AND ec3_sch.post_id IS NULL GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 10; What do I have to do to get rid of the very slow filesort? I would think that the multicolumn type_status_date index would be fast enough. The EXPLAIN EXTENDED output is below. +----+--------------------+-----------------------+--------+-----------------------------------+------------------+---------+---------------------------------------------------------------------------------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+--------------------+-----------------------+--------+-----------------------------------+------------------+---------+---------------------------------------------------------------------------------+------+----------------------------------------------+ | 1 | PRIMARY | wp_posts | ref | type_status_date | type_status_date | 124 | const,const | 7034 | Using where; Using temporary; Using filesort | | 1 | PRIMARY | wp_term_relationships | ref | PRIMARY | PRIMARY | 8 | bwog_wordpress_w.wp_posts.ID | 373 | Using index | | 1 | PRIMARY | wp_term_taxonomy | eq_ref | PRIMARY | PRIMARY | 8 | bwog_wordpress_w.wp_term_relationships.term_taxonomy_id | 1 | Using index | | 1 | PRIMARY | ec3_sch | ref | post_id_index | post_id_index | 9 | bwog_wordpress_w.wp_posts.ID | 1 | Using where; Using index | | 3 | DEPENDENT SUBQUERY | wp_term_taxonomy | range | PRIMARY,term_id_taxonomy,taxonomy | term_id_taxonomy | 106 | NULL | 2 | Using where | | 3 | DEPENDENT SUBQUERY | wp_term_relationships | eq_ref | PRIMARY,term_taxonomy_id | PRIMARY | 16 | bwog_wordpress_w.wp_posts.ID,bwog_wordpress_w.wp_term_taxonomy.term_taxonomy_id | 1 | Using index | | 2 | DEPENDENT SUBQUERY | tt | const | PRIMARY,term_id_taxonomy,taxonomy | term_id_taxonomy | 106 | const,const | 1 | | | 2 | DEPENDENT SUBQUERY | tr | eq_ref | PRIMARY,term_taxonomy_id | PRIMARY | 16 | func,const | 1 | Using index | +----+--------------------+-----------------------+--------+-----------------------------------+------------------+---------+---------------------------------------------------------------------------------+------+----------------------------------------------+ 8 rows in set, 2 warnings (0.05 sec) And CREATE TABLE: CREATE TABLE `wp_posts` ( `ID` bigint(20) unsigned NOT NULL auto_increment, `post_author` bigint(20) unsigned NOT NULL default '0', `post_date` datetime NOT NULL default '0000-00-00 00:00:00', `post_date_gmt` datetime NOT NULL default '0000-00-00 00:00:00', `post_content` longtext NOT NULL, `post_title` text NOT NULL, `post_excerpt` text NOT NULL, `post_status` varchar(20) NOT NULL default 'publish', `comment_status` varchar(20) NOT NULL default 'open', `ping_status` varchar(20) NOT NULL default 'open', `post_password` varchar(20) NOT NULL default '', `post_name` varchar(200) NOT NULL default '', `to_ping` text NOT NULL, `pinged` text NOT NULL, `post_modified` datetime NOT NULL default '0000-00-00 00:00:00', `post_modified_gmt` datetime NOT NULL default '0000-00-00 00:00:00', `post_content_filtered` text NOT NULL, `post_parent` bigint(20) unsigned NOT NULL default '0', `guid` varchar(255) NOT NULL default '', `menu_order` int(11) NOT NULL default '0', `post_type` varchar(20) NOT NULL default 'post', `post_mime_type` varchar(100) NOT NULL default '', `comment_count` bigint(20) NOT NULL default '0', `robotsmeta` varchar(64) default NULL, PRIMARY KEY (`ID`), KEY `post_name` (`post_name`), KEY `type_status_date` (`post_type`,`post_status`,`post_date`,`ID`), KEY `post_parent` (`post_parent`), KEY `post_date` (`post_date`), FULLTEXT KEY `post_related` (`post_title`,`post_content`) )

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  • MySQL create stored procedure fails but all internal queries succeed alone?

    - by Mark
    Hi all, I just created a simple database in MySQL, and I am learning how to write stored proc's. I'm familiar with M$SQL and as far as I can see the following should work: use mydb; -- -------------------------------------------------------------------------------- -- Routine DDL -- -------------------------------------------------------------------------------- DELIMITER // CREATE PROCEDURE mydb.doStats () BEGIN CREATE TABLE IF NOT EXISTS resultprobability ( ballNumber INT NOT NULL , probability FLOAT NULL, PRIMARY KEY (ballNumber) ); CREATE TABLE IF NOT EXISTS drawProbability ( drawDate DATE NOT NULL , ball1 INT NULL , ball2 INT NULL , ball3 INT NULL , ball4 INT NULL , ball5 INT NULL , ball6 INT NULL , ball7 INT NULL , score FLOAT NULL , PRIMARY KEY (drawDate) ); TRUNCATE TABLE resultprobability; TRUNCATE TABLE drawprobability; INSERT INTO resultprobability (ballNumber, probability) (select resultset.ballNumber ballNumber,(count(0)/(select count(0) from resultset)) probability from resultset group by resultset.ballNumber); INSERT INTO drawProbability (drawDate, ball1, ball2, ball3, ball4, ball5, ball6, ball7, score) (select distinct r.drawDate, a.ballnumber ball1, b.ballnumber ball2, c.ballnumber ball3, d.ballnumber ball4, e.ballnumber ball5, f.ballnumber ball6,g.ballnumber ball7, ((a.probability + b.probability + c.probability + d.probability + e.probability + f.probability + g.probability)/7) score from resultset r inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 1) a on a.drawdate = r.drawDate inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 2) b on b.drawdate = r.drawDate inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 3) c on c.drawdate = r.drawDate inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 4) d on d.drawdate = r.drawDate inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 5) e on e.drawdate = r.drawDate inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 6) f on f.drawdate = r.drawDate inner join (select r.drawDate, r.ballNumber, p.probability from resultset r inner join resultprobability p on p.ballNumber = r.ballNumber where r.appearence = 7) g on g.drawdate = r.drawDate order by score desc); END // DELIMITER ; instead i get the following Executed successfully in 0.002 s, 0 rows affected. Line 1, column 1 Error code 1064, SQL state 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 26 Line 6, column 1 Error code 1064, SQL state 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')) probability from resultset group by resultset.ballNumber); INSERT INTO d' at line 1 Line 31, column 51 Error code 1064, SQL state 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') score from resultset r inner join (select r.drawDate, r.ballNumber, p.probabi' at line 1 Line 39, column 114 Execution finished after 0.002 s, 3 error(s) occurred. What am I doing wrong? I seem to have exhausted my limited mental abilities!

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  • jQuery Datatables and ColumnFilterWidget integration issue

    - by user3520135
    I am trying to Place the ColumnFilterWidget plugin in the Header of the Datatables Table. Here are the changes i made in it : /** * Menu-based filter widgets based on distinct column values for a table. * * @class ColumnFilterWidgets * @constructor * @param {object} oDataTableSettings Settings for the target table. */ var ColumnFilterWidgets = function( oDataTableSettings ) { var me = this; var sExcludeList = ''; // me.$WidgetContainer = $( '<div class="column-filter-widgets"></div>' ); me.$WidgetContainer = $( '<tr class="head"></tr>' ); me.$MenuContainer = me.$WidgetContainer; me.$TermContainer = null; me.aoWidgets = []; me.sSeparator = ''; if ( 'oColumnFilterWidgets' in oDataTableSettings.oInit ) { if ( 'aiExclude' in oDataTableSettings.oInit.oColumnFilterWidgets ) { sExcludeList = '|' + oDataTableSettings.oInit.oColumnFilterWidgets.aiExclude.join( '|' ) + '|'; } if ( 'bGroupTerms' in oDataTableSettings.oInit.oColumnFilterWidgets && oDataTableSettings.oInit.oColumnFilterWidgets.bGroupTerms ) { me.$MenuContainer = $( '<div class="column-filter-widget-menus"></div>' ); me.$TermContainer = $( '<div class="column-filter-widget-selected-terms"></div>' ).hide(); } } // Add a widget for each visible and filtered column $.each( oDataTableSettings.aoColumns, function ( i, oColumn ) { var $columnTh = $( oColumn.nTh ); var $WidgetElem = $( '<th><div class="column-filter-widget"></div></th>' ); if ( oColumn.bVisible && sExcludeList.indexOf( '|' + i + '|' ) < 0 ) { me.aoWidgets.push( new ColumnFilterWidget( $WidgetElem, oDataTableSettings, i, me ) ); } me.$MenuContainer.append( $WidgetElem ); } ); if ( me.$TermContainer ) { me.$WidgetContainer.append( me.$MenuContainer ); me.$WidgetContainer.append( me.$TermContainer ); } oDataTableSettings.aoDrawCallback.push( { name: 'ColumnFilterWidgets', fn: function() { $.each( me.aoWidgets, function( i, oWidget ) { oWidget.fnDraw(); } ); } } ); return me; }; I added a extra <tr class='head'> inside the Datatable, and later on i am trying to append the Filters to that with attached to them,But instead of that it is creating new TR tag and then appending the filters in it. I even changed my dom of data tables to : dom: '<"clear">Cf<"clear">ltWrip', So the table elements should be there so that it can insert filters inside the head.

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