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• Booting the liveCD/USB in EFI mode fails on Samsung Tablet XE700T1A

  - by F.L.

  My tablet is Samsung Series 7 Slate (XE700T1A-A02FR (French Language)). It operates an Intel Sandy Bridge architecture. The main issue about this tablet is that it ships with an installed Windows 7 in (U)EFI mode (GPT partition table, etc.), so I'd like to get an EFI dual boot with Ubuntu. But it seems I can't boot on the liveCD in EFI mode. It starts loading (up to initrd), but I then get a blank (black) screen. I've tried the nomodeset kernel option (as well as removing quiet and splash) with no luck. [2012-09-27] I have used the Ubuntu 12.04.1 Desktop ISO (I have read somewhere that it is the only one that can boot in EFI mode). I'd say this has something to do with UEFI since the LiveCD boots in bios mode but not in efi mode. Besides, I am not sure my boot info will help, since I can't boot the LiveCD in EFI mode. As a result I can't install ubuntu in EFI mode. So it would be the boot info from the liveCD boot in bios mode. This happens on a ubuntu-12.04.1-desktop-amd64 iso used on a LiveUSB. Live USB was created by dd'ing the iso onto the full disk device (i.e. /dev/sdx no number) of the Flash drive. I have also tried copying the LiveCD files on a primary GPT partition, but with no luck, I just get the grub shell, no menu, no install option. [2012-09-28] I tried today a flash drive created with Ubuntu's Startup Disk Creator and the alternate 12.04.1 64 bit ISO. I get a grub menu in text mode (which meens it did start in efi mode) with install options / test options. But when I start any of these, I simply get a black screen (no cursor, neither mouse nor text-mode cursor). I tried removing the 'quiet' option and adding nomodeset and acpi=off, but it didn't do any good. So this is the same result as for the LiveCD. [2012-10-01] I have tried with a version of the secure remix version via usb-creator-gtk. The boot on the USB key has the same symptoms. Boot in EFI mode is impossible (I have menu but whatever entry I choose, I get the blank screen problem). The boot in BIOS mode works, I did the install. Then I used boot-repair to try installing grub-efi and get a system that would boot in efi mode. But I can't boot this system, because the EFI firmware doesn't seem to detect that sda contains a valid efi partition. Here is the resulting boot-info Boot info 1253554 [2012-10-01] Today, I have reinstalled the pre-shipped version of windows 7, and then installed ubuntu from a secure-remix iso dumped on USB flash drive vie usb-creator-gtk booted in BIOS mode. When install ended, I said "continue testing" then I used boot-repair to try get the bootloader installed. Now, when I boot the tablet, I get the grub menu, it can chainload windows 7 flawlessly. But when I try to start one of the ubuntu options I get the same old blank screen. Here is the new boot-info: Boot info 1253927 [2012-10-01] I tried installing the 3.3 kernel by chrooting a live usb boot (secure remix again) into the installed system. Same symptoms. I feel the key to this is that the device's efi firmware (which is EFI v2.0) would expose the graphics hardware in a way that prevents the kernel to initialize it, and thus prevents it from booting (the kernel stops all drive access just after the screen turns kind of very dark purple). Here is some info on the UEFI firmware as given by rEFInd: EFI revision: 2.00 Platform: x86_64 (64 bit) Firmware: American Megatrends 4.635 Screen Output: Graphics Output (UEFI), 800x600 [2012-10-08] This week end I tried loading the kernel with elilo. Eventhough I didn't have more luck on booting the kernel, elilo gives more info when loading the kernel. I think the next step is trying to load a kernel with EFI stub directly.

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• Good DBAs Do Baselines

  - by Louis Davidson

  One morning, you wake up and feel funny. You can’t quite put your finger on it, but something isn’t quite right. What now? Unless you happen to be a hypochondriac, you likely drag yourself out of bed, get on with the day and gather more “evidence”. You check your symptoms over the next few days; do you feel the same, better, worse? If better, then great, it was some temporal issue, perhaps caused by an allergic reaction to some suspiciously spicy chicken. If the same or worse then you go to the doctor for some health advice, but armed with some data to share, and having ruled out certain possible causes that are fixed with a bit of rest and perhaps an antacid. Whether you realize it or not, in comparing how you feel one day to the next, you have taken baseline measurements. In much the same way, a DBA uses baselines to gauge the gauge health of their database servers. Of course, while SQL Server is very willing to share data regarding its health and activities, it has almost no idea of the difference between good and bad. Over time, experienced DBAs develop “mental” baselines with which they can gauge the health of their servers almost as easily as their own body. They accumulate knowledge of the daily, natural state of each part of their database system, and so know instinctively when one of their databases “feels funny”. Equally, they know when an “issue” is just a passing tremor. They see their SQL Server with all of its four CPU cores running close 100% and don’t panic anymore. Why? It’s 5PM and every day the same thing occurs when the end-of-day reports, which are very CPU intensive, are running. Equally, they know when they need to respond in earnest when it is the first time they have heard about an issue, even if it has been happening every day. Nevertheless, no DBA can retain mental baselines for every characteristic of their systems, so we need to collect physical baselines too. In my experience, surprisingly few DBAs do this very well. Part of the problem is that SQL Server provides a lot of instrumentation. If you look, you will find an almost overwhelming amount of data regarding user activity on your SQL Server instances, and use and abuse of the available CPU, I/O and memory. It seems like a huge task even to work out which data you need to collect, let alone start collecting it on a regular basis, managing its storage over time, and performing detailed comparative analysis. However, without baselines, though, it is very difficult to pinpoint what ails a server, just by looking at a single snapshot of the data, or to spot retrospectively what caused the problem by examining aggregated data for the server, collected over many months. It isn’t as hard as you think to get started. You’ve probably already established some troubleshooting queries of the type SELECT Value FROM SomeSystemTableOrView. Capturing a set of baseline values for such a query can be as easy as changing it as follows: INSERT into BaseLine.SomeSystemTable (value, captureTime) SELECT Value, SYSDATETIME() FROM SomeSystemTableOrView; Of course, there are monitoring tools that will collect and manage this baseline data for you, automatically, and allow you to perform comparison of metrics over different periods. However, to get yourself started and to prove to yourself (or perhaps the person who writes the checks for tools) the value of baselines, stick something similar to the above query into an agent job, running every hour or so, and you are on your way with no excuses! Then, the next time you investigate a slow server, and see x open transactions, y users logged in, and z rows added per hour in the Orders table, compare to your baselines and see immediately what, if anything, has changed!

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• SQL Server Optimizer Malfunction?

  - by Tony Davis

  There was a sharp intake of breath from the audience when Adam Machanic declared the SQL Server optimizer to be essentially "stuck in 1997". It was during his fascinating "Query Tuning Mastery: Manhandling Parallelism" session at the recent PASS SQL Summit. Paraphrasing somewhat, Adam (blog | @AdamMachanic) offered a convincing argument that the optimizer often delivers flawed plans based on assumptions that are no longer valid with today’s hardware. In 1997, when Microsoft engineers re-designed the database engine for SQL Server 7.0, SQL Server got its initial implementation of a cost-based optimizer. Up to SQL Server 2000, the developer often had to deploy a steady stream of hints in SQL statements to combat the occasionally wilful plan choices made by the optimizer. However, with each successive release, the optimizer has evolved and improved in its decision-making. It is still prone to the occasional stumble when we tackle difficult problems, join large numbers of tables, perform complex aggregations, and so on, but for most of us, most of the time, the optimizer purrs along efficiently in the background. Adam, however, challenged further any assumption that the current optimizer is competent at providing the most efficient plans for our more complex analytical queries, and in particular of offering up correctly parallelized plans. He painted a picture of a present where complex analytical queries have become ever more prevalent; where disk IO is ever faster so that reads from disk come into buffer cache faster than ever; where the improving RAM-to-data ratio means that we have a better chance of finding our data in cache. Most importantly, we have more CPUs at our disposal than ever before. To get these queries to perform, we not only need to have the right indexes, but also to be able to split the data up into subsets and spread its processing evenly across all these available CPUs. Improvements such as support for ColumnStore indexes are taking things in the right direction, but, unfortunately, deficiencies in the current Optimizer mean that SQL Server is yet to be able to exploit properly all those extra CPUs. Adam’s contention was that the current optimizer uses essentially the same costing model for many of its core operations as it did back in the days of SQL Server 7, based on assumptions that are no longer valid. One example he gave was a "slow disk" bias that may have been valid back in 1997 but certainly is not on modern disk systems. Essentially, the optimizer assesses the relative cost of serial versus parallel plans based on the assumption that there is no IO cost benefit from parallelization, only CPU. It assumes that a single request will saturate the IO channel, and so a query would not run any faster if we parallelized IO because the disk system simply wouldn’t be able to handle the extra pressure. As such, the optimizer often decides that a serial plan is lower cost, often in cases where a parallel plan would improve performance dramatically. It was challenging and thought provoking stuff, as were his techniques for driving parallelism through query logic based on subsets of rows that define the "grain" of the query. I highly recommend you catch the session if you missed it. I’m interested to hear though, when and how often people feel the force of the optimizer’s shortcomings. Barring mistakes, such as stale statistics, how often do you feel the Optimizer fails to find the plan you think it should, and what are the most common causes? Is it fighting to induce it toward parallelism? Combating unexpected plans, arising from table partitioning? Something altogether more prosaic? Cheers, Tony.

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• Big Data – ClustrixDB – Extreme Scale SQL Database with Real-time Analytics, Releases Software Download – NewSQL

  - by Pinal Dave

  There are so many things to learn and there is so little time we all have. As we have little time we need to be selective to learn whatever we learn. I believe I know quite a lot of things in SQL but I still do not know what is around SQL. I have started to learn about NewSQL recently. If you wonder what is NewSQL I encourage all of you to read my blog post about NewSQL over here Big Data – Buzz Words: What is NewSQL – Day 10 of 21. NewSQL databases are quickly becoming popular – providing the scale of NoSQL with the SQL features and transactions. As a part of learning NewSQL database, I have recently started to learn about ClustrixDB. ClustrixDB has been the most mature NewSQL database used by some of the largest internet sites in the world for over 3 years, with extensive SQL support. In addition to scale, it provides fast real-time analytics by bringing massively parallel processing (MPP), available only in warehousing databases, to the transactional database. The reason I am more intrigued about learning ClustrixDB is their recent announcement on Oct 31. ClustrixDB was only available as an appliance, but now with their software release on Oct 31, everyone can use it. It is now available as forever free for up to 12 cores with community support, and there is a 45 day trial for unlimited cluster sizes. With the forever free world, I am indeed interested in ClustrixDB now. I know that few of the leading eCommerce sites in the world uses them for their transactional database. Here are few of the details I have quickly noted for ClustrixDB. ClustrixDB allows user to: Scale by simply adding nodes to the cluster with a single command Run billions of transactions a day Run fast real-time analytics Achieve high-availability with recovery from node failure Manages itself Easily migrate from MySQL as it is nearly plug-and-play compatible, use MySQL drivers, tools and replication. While I was going through the documentation I realized that ClustrixDB also has extensive support for SQL features including complex queries involving joins on a dozen or more tables, aggregates, sorts, sub-queries. It also supports stored procedures, triggers, foreign keys, partitioned and temporary tables, and fully online schema changes. It is indeed a very matured product and SQL solution. Indeed Clusterix sound very promising solution, I decided to dig a bit deeper to understand who are current customers of the Clustrix as they exist in the industry for quite a few years. Their client list is indeed very interesting and here is my quick research about them. Twoo.com – Europe’s largest social discovery (dating) site runs 4.4 Billion Transactions a day with table sizes over a Terabyte, on a 168 core cluster. EngageBDR – Top 3 in the online advertising category uses ClustrixDB to serve 6.9 billion ads a day through real-time bidding platform. Their reports went from 4 hours to 15 seconds. NoMoreRack – Top 2 fastest growing e-commerce company in US used ClustrixDB for high availability and fast growth through Amazon cloud. MakeMyTrip – India’s leading travel site runs on ClustrixDB with two clusters running as multi-master in Chennai and Bangalore. Many enterprises such as AOL, CSC, Rakuten, Symantec use ClustrixDB when their applications need scale. I must accept that I am impressed with the information I have learned so far and now is the time to do some hand’s on experience with their product. I want to learn this technology so in future when it is about NewSQL, I know what I am talking about. Read more why Clustrix explains why you ClustrixDB might be the right database for you. Download ClustrixDB with me today and install it on your machine so in future when we discuss the technical aspects of it, we all are on the same page. The software can be downloaded here. Reference : Pinal Dave (http://blog.SQLAuthority.com)Filed under: Big Data, MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Clustrix

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• Fresh Ubuntu Install - Grub not loading

  - by Ryan Sharp

  System Ubuntu 12.04 64-bit Windows 7 SP1 Samsung 64GB SSD - OS' Samsung 1TB HDD - Games, /Home, Swap WD 300'ishGB HDD - Backup Okay, so I'm very frustrated, so please excuse me if I miss anything out as my head is clouded by anger and impatience, etc. I'll try me best, though. First of all, I'll explain how I got to my predicament. I finally got my new SSD. I firstly installed Windows, which completed without a hitch. Afterwards, I tried to install Ubuntu, which failed several times due to problems irrelevant to this question, but I mention this to explain my frustrations, sorry. Anyway, I finally installed Ubuntu. However, I chose the 'bootloader' to be installed on the same partition as where I was installing the Ubuntu Root partition, as that was what I believed to be the best choice. It was of my thinking that it was supposed to go on the same partition and on the SSD, which is my OS drive, though with my problem, it apparently was wrong. So I tried to fix it by checking guides and following their directions, but seemed to have messed it up even more. Here is what I receive after I use the fdisk -l command: (I also added explanations for which I used each partition for) Disk /dev/sda: 64.0 GB, 64023257088 bytes 255 heads, 63 sectors/track, 7783 cylinders, total 125045424 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x324971d1 Device Boot Start End Blocks Id System /dev/sda1 * 2048 206847 102400 7 HPFS/NTFS/exFAT /dev/sda2 208896 48957439 24374272 7 HPFS/NTFS/exFAT /dev/sda3 48959486 125044735 38042625 5 Extended /dev/sda5 48959488 125044735 38042624 83 Linux sda1 --/ Windows Recovery sda2 --/ Windows 7 sda3/5 --/ Ubuntu root [ / ] Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xc0ee6a69 Device Boot Start End Blocks Id System /dev/sdb1 1024208894 1953523711 464657409 5 Extended /dev/sdb3 * 2048 1024206847 512102400 7 HPFS/NTFS/exFAT /dev/sdb5 1024208896 1939851263 457821184 83 Linux /dev/sdb6 1939853312 1953523711 6835200 82 Linux swap / Solaris sdb3 --/ Partition for Steam games, etc. sdb5 --/ Ubuntu Home [ /home ] sdb6 --/ Ubuntu Swap Partition table entries are not in disk order Disk /dev/sdc: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x292eee23 Device Boot Start End Blocks Id System /dev/sdc1 2048 625141759 312569856 7 HPFS/NTFS/exFAT sdc1 --/ Generic backup I also used a Boot Script that other users suggested, so that I can give more details on my partitions and also where Grub is located... ============================= Boot Info Summary: =============================== => Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos5)/boot/grub on this drive. => Grub2 (v1.99) is installed in the MBR of /dev/sdb and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos5)/boot/grub on this drive. => Windows is installed in the MBR of /dev/sdc. Now that is weird... Why would Grub2 be installed on both my SSD and HDD? Even weirder is why is Windows on the MBR of my backup hard drive? Nothing I did should have done that... Anyway, here is the entire Output from that script... PASTEBIN So, to summarize what I need: How can I fix my setup so grub loads on startup? How can I clean my partitions to remove unnecessary grubs? What did I do wrong so that I don't do something so daft again? Thank you so much for reading, and I hope you can help me. I've been trying to have a successful setup since Friday, and I'm almost at the point that I'm really tempted to throw my computer out the window due to my frustration.

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• What is the best practice, point of view of well experienced developers

  - by Damien MIRAS

  My manager pushes me to use his self defined best practices. All of these practices are based on is own assumptions. I disagree with them and I would like to have some feedback of well experienced people about these practices. I would prefer answers from people involved in the maintenance of huge products and people whom have maintained the product for years. Developers with 15+ years of experience are preferred because my manager has that much experience himself. I have 7 years of experience. Here are the practices he wants me to use: never extends classes, use composition and interface instead because extending classes are unmaintainable and difficult to debug. What I think about that Extend when needed, respect "Liskov's Substitution Principle" and you'll never be stuck with a problem, but prefer composition and decoration. I don't know any serious project which has banned inheriting, sometimes it's impossible to not use that, i.e. in a UI framework. Design patterns are just unusable. In PHP, for simple use cases (for example a user needs a web interface to view a database table), his "best practice" is: copy some random php code wich we own, paste and modify it, put html and php code in same file, never use classes in PHP, it doesn't work well for small jobs, and in fact it doesn't work well at all, there is no good tool to work with. Copy & paste PHP code is good practice for maintenance because scripts are independent, if you have a bug somewhere you can fix it without side effects. What I think about that: NEVER EVER COPY code or do it because you have five minutes to deliver something, you will do some refactoring after that. Copy & paste code is a beginners error, if you have errors you'll have the error everywhere any time you have pasted it's a nightmare to maintain. If you repsect the "Open Close Principle" you'll rarely get edge effects, use unit test if you are afraid of that. For small jobs in PHP use at least something you get or write the HTML separately from the PHP code and reuse it any time you need it. Classes in PHP are mature, not as mature as other languages like python or java, but they are usable. There is tools to work with classes in PHP like Zend Studio that work very well. The use of classes or not depends not on the language you use but the programming paradigm you have choosen. I'm a OOP developer, I use PHP5, why do I have to shoot myself in the foot? When you find a simple bug in the code, and you can fix it simply, if you are not working on the code where you have found it, never fix it, even if it takes 5 seconds. He says to me his "best practices" are driven by the fact that he has a lot of experience in maintaining software in production (14 years) and he now knows what works and what doesn't work, what the community says is a fad, and the people advocating such principles as never copy & paste code, are not evolved in maintaining applications. What I think about that: If you find a bug fix it if you can do it quickly inform the people who've touched that code before, check if you have not introduced a new bug, ideally add a unit test for it. I currently work on a web commerce project, which serves 15k unique users per day. The code base has to be maintained and has been maintained this way since 2005. Ideally you include a short description of your position and experience in terms of years effectively maintaining an application which has been in production for real.

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• Oracle ties social, CRM, analytics products to customer experience

  - by Richard Lefebvre

  Oracle will embark on a new product strategy that centers on customer experience management, an approach driven by the company’s many recent acquisitions.  The new approach, announced by the company Monday night, will be seen in an expansive suite that features familiar Oracle products -- such as its Fusion CRM platform -- and offerings the company recently gained through acquisitions, including FatWire, RightNow and Vitrue. Billed as Oracle Customer Experience (CX), the suite enables businesses to respond to a market centered on the customer experience, said Anthony Lye, the company’s senior vice president of CRM. Companies “are very aware their products are commoditizing,” Lye said in an interview last week, referring to how the Web and social media channels have empowered customers. Customer experiences start and mature outside of CRM, and applications today need to reflect that shift, Lye said. Businesses thus need to step away from a pure CRM model, he said. Oracle claims CX will improve customer experience management by connecting businesses with customers across Web sites and social channels. Companies can create a single, real-time view of the customer and use predictive analytics of interactions to strengthen the customer experience, Oracle said. “Companies have to connect with their customers wherever, whenever and however they want,” Lye said. “They have to know and understand their customer.” Lye promoted Oracle CX as a suite that will work across channels to complement the company’s applications. A new strategy has been “cooking” for years now, but the acquisitions Oracle has made over the past two years made the time right for a “unique collaboration,” Lye said. CX includes basic Oracle CRM solutions such as Siebel and the new Fusion Apps. It also includes the company’s MDM products, Enterprise Data Quality, Customer Hub and Product Hub. And the suite is rounded out by the services that Oracle recently bought, transactions that created or enhanced the company’s presence in social, marketing, e-commerce and customer service. For instance, FatWire provides tools for marketing. ATG focuses on e-commerce. And RightNow specializes in customer service. Two recent acquisitions -- Collective Intellect and Vitrue -- gave Oracle a seat at the social table. Collective Intellect is a social intelligence program, and Vitrue is a social marketing and engagement platform. Those acquisitions have yet to be finalized. Oracle hopes to eventually integrate the two social offerings, as well as most of the other services, into the CX suite. CX can integrate on Oracle’s standard middleware, and can give users a lower TCO by leveraging it as a single stack on premise or as a cloud solution. Lye deferred questions about the pricing of CX, and instead pitched Oracle’s ability to offer multiple customer experience solutions in one suite. Businesses have struggled with the complexity of infrastructure and modern services that communicate with customers, Lye said. “They’ve struggled to pull all these things together. We’ve done that,” he said. Stephen Powers, a research director at Forrester Research Inc. in Cambridge, Mass., said it’s not surprising for Oracle to offer the CX suite and a related customer experience strategy.  “They’ve got CRM, ATG, FatWire. Clearly, it’s been the strategy for them,” he said. But the challenge for Oracle, and for any other vendor that has gone on an “acquisition spree,” is to connect its many products, Powers said. “The portfolio has to be more than the parts. They’ve got to realize the efficiencies and value of having these pieces to tie them together,” he said. “The proof is in the pudding. Adobe has done a nice job in its space with the products they’ve got. Now, Oracle has got to show it has something.” Albert McKeon (SearchCRM) Published: 25 Jun 2012 : http://searchcrm.techtarget.com/news/2240158644/Oracle-ties-social-CRM-analytics-products-to-customer-experience

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• How do you formulate the Domain Model in Domain Driven Design properly (Bounded Contexts, Domains)?

  - by lko

  Say you have a few applications which deal with a few different Core Domains. The examples are made up and it's hard to put a real example with meaningful data together (concisely). In Domain Driven Design (DDD) when you start looking at Bounded Contexts and Domains/Sub Domains, it says that a Bounded Context is a "phase" in a lifecycle. An example of Context here would be within an ecommerce system. Although you could model this as a single system, it would also warrant splitting into separate Contexts. Each of these areas within the application have their own Ubiquitous Language, their own Model, and a way to talk to other Bounded Contexts to obtain the information they need. The Core, Sub, and Generic Domains are the area of expertise and can be numerous in complex applications. Say there is a long process dealing with an Entity for example a Book in a core domain. Now looking at the Bounded Contexts there can be a number of phases in the books life-cycle. Say outline, creation, correction, publish, sale phases. Now imagine a second core domain, perhaps a store domain. The publisher has its own branch of stores to sell books. The store can have a number of Bounded Contexts (life-cycle phases) for example a "Stock" or "Inventory" context. In the first domain there is probably a Book database table with basically just an ID to track the different book Entities in the different life-cycles. Now suppose you have 10+ supporting domains e.g. Users, Catalogs, Inventory, .. (hard to think of relevant examples). For example a DomainModel for the Book Outline phase, the Creation phase, Correction phase, Publish phase, Sale phase. Then for the Store core domain it probably has a number of life-cycle phases. public class BookId : Entity { public long Id { get; set; } } In the creation phase (Bounded Context) the book could be a simple class. public class Book : BookId { public string Title { get; set; } public List<string> Chapters { get; set; } //... } Whereas in the publish phase (Bounded Context) it would have all the text, release date etc. public class Book : BookId { public DateTime ReleaseDate { get; set; } //... } The immediate benefit I can see in separating by "life-cycle phase" is that it's a great way to separate business logic so there aren't mammoth all-encompassing Entities nor Domain Services. A problem I have is figuring out how to concretely define the rules to the physical layout of the Domain Model. A. Does the Domain Model get "modeled" so there are as many bounded contexts (separate projects etc.) as there are life-cycle phases across the core domains in a complex application? Edit: Answer to A. Yes, according to the answer by Alexey Zimarev there should be an entire "Domain" for each bounded context. B. Is the Domain Model typically arranged by Bounded Contexts (or Domains, or both)? Edit: Answer to B. Each Bounded Context should have its own complete "Domain" (Service/Entities/VO's/Repositories) C. Does it mean there can easily be 10's of "segregated" Domain Models and multiple projects can use it (the Entities/Value Objects)? Edit: Answer to C. There is a complete "Domain" for each Bounded Context and the Domain Model (Entity/VO layer/project) isn't "used" by the other Bounded Contexts directly, only via chosen paths (i.e. via Domain Events). The part that I am trying to figure out is how the Domain Model is actually implemented once you start to figure out your Bounded Contexts and Core/Sub Domains, particularly in complex applications. The goal is to establish the definitions which can help to separate Entities between the Bounded Contexts and Domains.

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• Where should you put constants and why?

  - by Tim Meyer

  In our mostly large applications, we usually have a only few locations for constants: One class for GUI and internal contstants (Tab Page titles, Group Box titles, calculation factors, enumerations) One class for database tables and columns (this part is generated code) plus readable names for them (manually assigned) One class for application messages (logging, message boxes etc) The constants are usually separated into different structs in those classes. In our C++ applications, the constants are only defined in the .h file and the values are assigned in the .cpp file. One of the advantages is that all strings etc are in one central place and everybody knows where to find them when something must be changed. This is especially something project managers seem to like as people come and go and this way everybody can change such trivial things without having to dig into the application's structure. Also, you can easily change the title of similar Group Boxes / Tab Pages etc at once. Another aspect is that you can just print that class and give it to a non-programmer who can check if the captions are intuitive, and if messages to the user are too detailed or too confusing etc. However, I see certain disadvantages: Every single class is tightly coupled to the constants classes Adding/Removing/Renaming/Moving a constant requires recompilation of at least 90% of the application (Note: Changing the value doesn't, at least for C++). In one of our C++ projects with 1500 classes, this means around 7 minutes of compilation time (using precompiled headers; without them it's around 50 minutes) plus around 10 minutes of linking against certain static libraries. Building a speed optimized release through the Visual Studio Compiler takes up to 3 hours. I don't know if the huge amount of class relations is the source but it might as well be. You get driven into temporarily hard-coding strings straight into code because you want to test something very quickly and don't want to wait 15 minutes just for that test (and probably every subsequent one). Everybody knows what happens to the "I will fix that later"-thoughts. Reusing a class in another project isn't always that easy (mainly due to other tight couplings, but the constants handling doesn't make it easier.) Where would you store constants like that? Also what arguments would you bring in order to convince your project manager that there are better concepts which also comply with the advantages listed above? Feel free to give a C++-specific or independent answer. PS: I know this question is kind of subjective but I honestly don't know of any better place than this site for this kind of question. Update on this project I have news on the compile time thing: Following Caleb's and gbjbaanb's posts, I split my constants file into several other files when I had time. I also eventually split my project into several libraries which was now possible much easier. Compiling this in release mode showed that the auto-generated file which contains the database definitions (table, column names and more - more than 8000 symbols) and builds up certain hashes caused the huge compile times in release mode. Deactivating MSVC's optimizer for the library which contains the DB constants now allowed us to reduce the total compile time of your Project (several applications) in release mode from up to 8 hours to less than one hour! We have yet to find out why MSVC has such a hard time optimizing these files, but for now this change relieves a lot of pressure as we no longer have to rely on nightly builds only. That fact - and other benefits, such as less tight coupling, better reuseability etc - also showed that spending time splitting up the "constants" wasn't such a bad idea after all ;-)

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• How do I configure WakeOnUSB properly?

  - by wishi

  How do I configure Wake-On-USB properly on a 10.04 or 10.10 Ubuntu (2.6.36 and higher if needed)? (Wake-on-USB is when the computer is asleep and for example a USB Keyboard event wakes up the machine!) The notebook is an Acer Aspire Timeline X 1830T. I don't know in which way the Linux Kernel supports the controllers. There are different ways to approach this, for example /proc/acpi/wakeup... or UDEV... or something with HAL? /proc/acpi/wakeup shows every device in S4, but I need S3. Device S-state Status Sysfs node P0P2 S4 *disabled PEGP S4 *disabled P0P1 S0 *disabled pci:0000:00:1e.0 EHC1 S4 *disabled pci:0000:00:1d.0 USB1 S4 *enabled USB2 S4 *disabled USB3 S4 *disabled USB4 S4 *disabled EHC2 S4 *disabled pci:0000:00:1a.0 USB5 S4 *disabled USB6 S4 *disabled USB7 S4 *disabled HDEF S0 *disabled pci:0000:00:1b.0 RP01 S5 *disabled pci:0000:00:1c.0 PXSX S5 *disabled pci:0000:01:00.0 RP02 S0 *disabled pci:0000:00:1c.1 PXSX S5 *disabled pci:0000:02:00.0 RP03 S0 *disabled PXSX S5 *disabled RP04 S0 *disabled PXSX S5 *disabled RP05 S0 *disabled PXSX S5 *disabled RP07 S0 *disabled PXSX S5 *disabled RP08 S0 *disabled PXSX S5 *disabled GLAN S0 *disabled PEG3 S4 *disabled PEG5 S4 *disabled PEG6 S4 *disabled SLPB S3 *enabled S4, which is Suspend-To-Disk afaik... doesn't seem to work either if I echo USB1 into the wakeup table. It just sets an S4 flag. can I get the USB ports in S3? I want to make the machine wakeup from Suspend-To-Ram (S3, ACPI standard) in case a key on my external keyboard is pressed. It only wakes up if a key on the internal Laptop keyboard is pressed... from Suspend To Ram. It seems if I plug in a USB mouse, that the USB port isn't even powered. I have no BIOS option to change this. Further specific information regarding the device: usb-devices T: Bus=01 Lev=02 Prnt=02 Port=01 Cnt=01 Dev#= 13 Spd=1.5 MxCh= 0 D: Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=04d9 ProdID=1603 Rev=03.10 S: Manufacturer= S: Product=USB Keyboard C: #Ifs= 2 Cfg#= 1 Atr=a0 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=01 Driver=usbhid I: If#= 1 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=00 Prot=00 Driver=usbhid root@underwater-laptop:/# lsusb [...] Bus 001 Device 013: ID 04d9:1603 Holtek Semiconductor, Inc. Bus 001 Device 004: ID 0bda:0138 Realtek Semiconductor Corp. Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub [...] If this doesn't work I have to properly explain why :( - but I think it is very hard to research this kernel internal. Any hints for good information here? I hope it's possible... I'm just looking for any solution. edit: this, waking up on USB, works on Windows! Thanks a lot, Marius

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• Part 6: Extensions vs. Modifications

  - by volker.eckardt(at)oracle.com

  Customizations = Extensions + Modifications In the EBS terminology, a customization can be an extension or a modification. Extension means that you mainly create your own code from scratch. You may utilize existing views, packages and java classes, but your code is unique. Modifications are quite different, because here you take existing code and change or enhance certain areas to achieve a slightly different behavior. Important is that it doesn't matter if you place your code at the same or at another place – it is a modification. It is also not relevant if you leave the original code enabled or not! Why? Here is the answer: In case the original code piece you have taken as your base will get patched, you need to copy the source again and apply all your changes once more. If you don't do that, you may get different results or write different data compared to the standard – this causes a high risk! Here are some guidelines how to reduce the risk: Invest a bit longer when searching for objects to select data from. Rather choose a view than a table. In case Oracle development changes the underlying tables, the view will be more stable and is therefore a better choice. Choose rather public APIs over internal APIs. Same background as before: although internal structure might change, the public API is more stable. Use personalization and substitution rather than modification. Spend more time to check if the requirement can be covered with such techniques. Build a project code library, avoid that colleagues creating similar functionality multiple times. Otherwise you have to review lots of similar code to determine the need for correction. Use the technique of “flagged files”. Flagged files is a way to mark a standard deployment file. If you run the patch analyse (within Application Manager), the analyse result will list flagged standard files in case they will be patched. If you maintain a cross reference to your own CEMLIs, you can easily determine which CEMLIs have to be reviewed. Implement a code review process. This can be done by utilizing team internal or external persons. If you implement such a team internal process, your team members will come up with suggestions how to improve the code quality by themselves. Review heavy customizations regularly, to identify options to reduce complexity; let's say perform this every 6th month. You may not spend days for such a review, but a high level cross check if the customization can be reduced is suggested. De-install customizations which are no more required. Define a process for this. Add a section into the technical documentation how to uninstall and what are possible implications. Maintain a cross reference between CEMLIs and between CEMLIs, EBS modules and business processes. Keep this list up to date! Share this list! By following these guidelines, you are able to improve product stability. Although we might not be able to avoid modifications completely, we can give a much better advise to developers and to our test team. Summary: Extensions and Modifications have to be handled differently during their lifecycle. Modifications implicate a much higher risk and should therefore be reviewed more frequently. Good cross references allow you to give clear advise for the testing activities.

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• Utility to Script SQL Server Configuration

  - by Bill Graziano

  I wrote a small utility to script some key SQL Server configuration information. I had two goals for this utility: Assist with disaster recovery preparation Identify configuration changes I’ve released the application as open source through CodePlex. You can download it from CodePlex at the Script SQL Server Configuration project page. The application is a .NET 2.0 console application that uses SMO. It writes its output to a directory that you specify.  Disaster Planning ScriptSqlConfig generates scripts for logins, jobs and linked servers.  It writes the properties and configuration from the instance to text files. The scripts are designed so they can be run against a DR server in the case of a disaster. The properties and configuration will need to be manually compared. Each job is scripted to its own file. Each linked server is scripted to its own file. The linked servers don’t include the password if you use a SQL Server account to connect to the linked server. You’ll need to store those somewhere secure. All the logins are scripted to a single file. This file includes windows logins, SQL Server logins and any server role membership.  The SQL Server logins are scripted with the correct SID and hashed passwords. This means that when you create the login it will automatically match up to the users in the database and have the correct password. This is the only script that I programmatically generate rather than using SMO. The SQL Server configuration and properties are scripted to text files. These will need to be manually reviewed in the event of a disaster. Or you could DIFF them with the configuration on the new server. Configuration Changes These scripts and files are all designed to be checked into a version control system.  The scripts themselves don’t include any date specific information. In my environments I run this every night and check in the changes. I call the application once for each server and script each server to its own directory.  The process will delete any existing files before writing new ones. This solved the problem I had where the scripts for deleted jobs and linked servers would continue to show up.  To see any changes I just need to query the version control system to show many any changes to the files. Database Scripting Utilities that script database objects are plentiful.  CodePlex has at least a dozen of them including one I wrote years ago. The code is so easy to write it’s hard not to include that functionality. This functionality wasn’t high on my list because it’s included in a database backup.  Unless you specify the /nodb option, the utility will script out many user database objects. It will script one object per file. It will script tables, stored procedures, user-defined data types, views, triggers, table types and user-defined functions. I know there are more I need to add but haven’t gotten around it yet. If there’s something you need, please log an issue and get it added. Since it scripts one object per file these really aren’t appropriate to recreate an empty database. They are really good for checking into source control every night and then seeing what changed. I know everyone tells me all their database objects are in source control but a little extra insurance never hurts. Conclusion I hope this utility will help a few of you out there. My goal is to have it script all server objects that aren’t contained in user databases. This should help with configuration changes and especially disaster recovery.

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• Asynchrony in C# 5 (Part I)

  - by javarg

  I’ve been playing around with the new Async CTP preview available for download from Microsoft. It’s amazing how language trends are influencing the evolution of Microsoft’s developing platform. Much effort is being done at language level today than previous versions of .NET. In these post series I’ll review some major features contained in this release: Asynchronous functions TPL Dataflow Task based asynchronous Pattern Part I: Asynchronous Functions This is a mean of expressing asynchronous operations. This kind of functions must return void or Task/Task<> (functions returning void let us implement Fire & Forget asynchronous operations). The two new keywords introduced are async and await. async: marks a function as asynchronous, indicating that some part of its execution may take place some time later (after the method call has returned). Thus, all async functions must include some kind of asynchronous operations. This keyword on its own does not make a function asynchronous thought, its nature depends on its implementation. await: allows us to define operations inside a function that will be awaited for continuation (more on this later). Async function sample: Async/Await Sample async void ShowDateTimeAsync() {     while (true)     {         var client = new ServiceReference1.Service1Client();         var dt = await client.GetDateTimeTaskAsync();         Console.WriteLine("Current DateTime is: {0}", dt);         await TaskEx.Delay(1000);     } } The previous sample is a typical usage scenario for these new features. Suppose we query some external Web Service to get data (in this case the current DateTime) and we do so at regular intervals in order to refresh user’s UI. Note the async and await functions working together. The ShowDateTimeAsync method indicate its asynchronous nature to the caller using the keyword async (that it may complete after returning control to its caller). The await keyword indicates the flow control of the method will continue executing asynchronously after client.GetDateTimeTaskAsync returns. The latter is the most important thing to understand about the behavior of this method and how this actually works. The flow control of the method will be reconstructed after any asynchronous operation completes (specified with the keyword await). This reconstruction of flow control is the real magic behind the scene and it is done by C#/VB compilers. Note how we didn’t use any of the regular existing async patterns and we’ve defined the method very much like a synchronous one. Now, compare the following code snippet  in contrast to the previuous async/await: Traditional UI Async void ComplicatedShowDateTime() {     var client = new ServiceReference1.Service1Client();     client.GetDateTimeCompleted += (s, e) =>     {         Console.WriteLine("Current DateTime is: {0}", e.Result);         client.GetDateTimeAsync();     };     client.GetDateTimeAsync(); } The previous implementation is somehow similar to the first shown, but more complicated. Note how the while loop is implemented as a chained callback to the same method (client.GetDateTimeAsync) inside the event handler (please, do not do this in your own application, this is just an example).  How it works? Using an state workflow (or jump table actually), the compiler expands our code and create the necessary steps to execute it, resuming pending operations after any asynchronous one. The intention of the new Async/Await pattern is to let us think and code as we normally do when designing and algorithm. It also allows us to preserve the logical flow control of the program (without using any tricky coding patterns to accomplish this). The compiler will then create the necessary workflow to execute operations as the happen in time.

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• Refactoring existing PHP Project. I need some advices

  - by b0x

  i have a small SAS ERP that was written some years ago using PHP. At that time, it didn't used any framework, but the code isn't a mess as i will explain more detailed in the following lines. Nowadays, the project grow and I’m now working with 3 more programmers. Often, they ask to me why we don’t migrate to a framework such Laravel. Although I'd love trying Laravel, I’m a small business and i don't have time/money to stop and spend a whole year building everything from scratch. I need to live and pay the bills. So, I've read a lot about this matter, and I decided that doing a refactoring is the best way to do it. Also, I'm not so sure that a framework will make things easy. Business goals are: Make the code easier to new hired programmers I must separate the "view", because: I want to release different versions of this product (using the same code), but under different brands and websites at the minimum cost (just changing view) Release different versions to fit mobile/tablet. Make different types of this product, seeling packages as if it were plugins. Develop custom packages for some costumers (like plugins/addon's that they can buy to put on the main application). Code goals: Introduce best pratices, standards for everyone Try to build my own MVC structure Improve validation of data/forms (today they are mixed in both ajax and classes) Create automated testing rotines, to quality assurance. My actual structure project: class\ extra\ hd\ logs\ public_html\ public_html\includes\ public_html\css|js|images\ class\ There are three types of classes. They are all “autoloaded” with something similar with PSR-0, but I don’t use namespaces. 1. class.Something.php Connects to Database using specific methods. I.e: Costumer-list(); It uses “class.Db.php”, that it’s an abstraction of mysqli on every method. 2. class.SomethingProc.php Do things that “join” things that come from “class.Something.php”. Like IF/ELSE, math operations. 3. class.SomethingHTML.php The classes with “HTML” suffix implements only static methods and HTML code only. A real life example: All the programmers need to use $cSomething ($c to class) and $arrSomething (to array). Costumer.php (view) <?php $cCosumter = new Costumer(); $arrCostumer = $cCostumer->list(); echo CostumerHTML::table($arrCostumer); ?> Extra\ Store 3rdparty projects/classes from others, such MPDF, PHPMailer, etc. Hd\ Store user’s fies outsite wwwroot dir. Logs\ Store phplogs and the system itself logs (We have a static Log::error() method, that we put in every method of every class) Public_html\ Stores the files that people use. Public_html\includes\ Store the main “config.php” file and all files that do “ajax things” ajax.Costumer.php, for example. Help is needed ;) So, as you can see we have some standards, and also for database things. But i want to write a manual of our rules. Something that i can give to any new programmer at my companie and he can go on. This is not totally a mess, but It could be better seeing the new practices. What could I do to separate this as MVC, to have multiple VIEW’s. Could you gimme some tips considering my goals? Keep im mind the different products/custom things for specific costumers without breaking the main application. URL for tutorials, books, etc. It would be nice. Thanks!

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• TechEd North America 2012 – Day 1 #msTechEd

  - by Marco Russo (SQLBI)

  Yesterday I and Alberto delivered the PreCon day about BISM Tabular in Analysis Services 2012. We received very good feedback and now I am looking forward to meet people that read our blogs and our books! Ping me on Twitter at @marcorus if you want to contact me during the conference. This is my schedule for the next few days: ·         Monday, June 11, 2012 o   10:30am-12:30pm I will be in the Technical Learning Center area, at the Breaktrough Insights (station #8) in the Database & Business Intelligence area (dedicated to SQL Server 2012) o   I will try to watch some sessions in the afternoon o   6:30pm-7:00pm I will be at the O’Reilly booth meeting book readers and doing some book signing ·         Tuesday, June 12, 2012 o   12:30pm-3:30pm I will be in the Technical Learning Center area, at the Breaktrough Insights (station #8) in the Database & Business Intelligence area (dedicated to SQL Server 2012) o   5:00pm-6:15pm I will attend the Alberto’s session DBI413 Many-to-Many Relationships in BISM Tabular (room S330E) o   6:15pm-9:00pm Community Night & Ask the Experts, we’ll discuss about Analysis Services, Tabular and Multidimensional! ·         Wednesday, June 13, 2012 o   11:15am-11:30am Don’t miss this special demo session at the Private Cloud, Public Cloud and Data Platform Theater in the Technical Learning Center area (next to the SQL Server 2012 zone). I and Alberto will present Querying multi-billion rows with many to many relationships in SSAS Tabular (xVelocity) and you’re invited to guess the response time of DAX queries on a 4 billion rows table with many-to-many relationships before we run them! We’ll give away some 8GB USB key if you guess the right answer! o   12:30pm-1:00pm I and Alberto will have a book signing session at the TechEd Bookstore o   3:00pm-5:00pm I will be in the Technical Learning Center area, at the Breaktrough Insights (station #8) in the Database & Business Intelligence area (dedicated to SQL Server 2012) ·         Thursday, June 14, 2012 o   2:45pm-4:00pm I will deliver my DBI319 BISM: Multidimensional vs. Tabular breakthrough session in room S320A. I expect many questions here! And if you want to learn more about Analysis Services Tabular, we announced two more online sessions of our SSAS Tabular Workshop: ·         July 2-3, 2012 - SSAS Workshop Online - America's time zone ·         September 3-4, 2012 - SSAS Workshop Online - America's time zone Register now if you are interested, the early bird for the July session expires on June 19, 2012! I will also deliver a SSAS Workshop in Oslo (Norway) on August 27-28, 2012.  

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• Mobile Deals: the Consumer Wants You in Their Pocket

  - by Mike Stiles

  Mobile deals offer something we talk about a lot in social marketing, relevant content. If a consumer is already predisposed to liking your product and gets a timely deal for it that’s easy and convenient to use, not only do you score on the marketing side, it clearly generates some of that precious ROI that’s being demanded of social. First, a quick gut-check on the public’s adoption of mobile. Nielsen figures have 55.5% of US mobile owners using smartphones. If young people are indeed the future, you can count on the move to mobile exploding exponentially. Teens are the fastest growing segment of smartphone users, and 58% of them have one. But the largest demographic of smartphone users is 25-34 at 74%. That tells you a focus on mobile will yield great results now, and even better results straight ahead. So we can tell both from statistics and from all the faces around you that are buried in their smartphones this is where consumers are. But are they looking at you? Do you have a valid reason why they should? Everybody likes a good deal. BIA/Kelsey says US consumers will spend $3.6 billion this year for daily deals (the Groupons and LivingSocials of the world), up 87% from 2011. The report goes on to say over 26% of small businesses are either "very likely" or "extremely likely" to offer up a deal in the next 6 months. Retail Gazette reports 58% of consumers shop with coupons, a 40% increase in 4 years. When you consider that a deal can be the impetus for a real-world transaction, a first-time visit to a store, an online purchase, entry into a loyalty program, a social referral, a new fan or follower, etc., that 26% figure shows us there’s a lot of opportunity being left on the table by brands. The existing and emerging technologies behind mobile devices make the benefits of offering deals listed above possible. Take how mobile payment systems are being tied into deal delivery and loyalty programs. If it’s really easy to use a coupon or deal, it’ll get used. If it’s complicated, it’ll be passed over as “not worth it.” When you can pay with your mobile via technologies that connects store and user, you get the deal, you get the loyalty credit, you pay, and your receipt is uploaded, all in one easy swipe. Nothing to keep track of, nothing to lose or forget about. And the store “knows” you, so future offers will be based on your tastes. Consider the endgame. A customer who’s a fan of your belt buckle store’s Facebook Page is in one of your physical retail locations. They pull up your app, because they’ve gotten used to a loyalty deal being offered when they go to your store. Voila. A 10% discount active for the next 30 minutes. Maybe the app also surfaces social references to your brand made by friends so they can check out a buckle someone’s raving about. If they aren’t a fan of your Page or don’t have your app, perhaps they’ve opted into location-based deal services so you can still get them that 10% deal while they’re in the store. Or maybe they’ve walked in with a pre-purchased Groupon or Living Social voucher. They pay with one swipe, and you’ve learned about their buying preferences, credited their loyalty account and can encourage them to share a pic of their new buckle on social. Happy customer. Happy belt buckle company. All because the brand was willing to use the tech that’s available to meet consumers where they are, incentivize them, and show them how much they’re valued through rewards.

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• When row estimation goes wrong

  - by Dave Ballantyne

  Whilst working at a client site, I hit upon one of those issues that you are not sure if that this is something entirely new or a bug or a gap in your knowledge. The client had a large query that needed optimizing.  The query itself looked pretty good, no udfs, UNION ALL were used rather than UNION, most of the predicates were sargable other than one or two minor ones.  There were a few extra joins that could be eradicated and having fixed up the query I then started to dive into the plan. I could see all manor of spills in the hash joins and the sort operations,  these are caused when SQL Server has not reserved enough memory and has to write to tempdb.  A VERY expensive operation that is generally avoidable.  These, however, are a symptom of a bad row estimation somewhere else, and when that bad estimation is combined with other estimation errors, chaos can ensue. Working my way back down the plan, I found the cause, and the more I thought about it the more i came convinced that the optimizer could be making a much more intelligent choice. First step is to reproduce and I was able to simplify the query down a single join between two tables, Product and ProductStatus,  from a business point of view, quite fundamental, find the status of particular products to show if ‘active’ ,’inactive’ or whatever. The query itself couldn’t be any simpler The estimated plan looked like this: Ignore the “!” warning which is a missing index, but notice that Products has 27,984 rows and the join outputs 14,000. The actual plan shows how bad that estimation of 14,000 is : So every row in Products has a corresponding row in ProductStatus.  This is unsurprising, in fact it is guaranteed,  there is a trusted FK relationship between the two columns.  There is no way that the actual output of the join can be different from the input. The optimizer is already partly aware of the foreign key meta data, and that can be seen in the simplifiction stage. If we drop the Description column from the query: the join to ProductStatus is optimized out. It serves no purpose to the query, there is no data required from the table and the optimizer knows that the FK will guarantee that a matching row will exist so it has been removed. Surely the same should be applied to the row estimations in the initial example, right ?  If you think so, please upvote this connect item. So what are our options in fixing this error ? Simply changing the join to a left join will cause the optimizer to think that we could allow the rows not to exist. or a subselect would also work However, this is a client site, Im not able to change each and every query where this join takes place but there is a more global switch that will fix this error,  TraceFlag 2301. This is described as, perhaps loosely, “Enable advanced decision support optimizations”. We can test this on the original query in isolation by using the “QueryTraceOn” option and lo and behold our estimated plan now has the ‘correct’ estimation. Many thanks goes to Paul White (b|t) for his help and keeping me sane through this

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• how to write the code for this program specially in mathematica? [closed]

  - by asd

  I implemented a solution to the problem below in Mathematica, but it takes a very long time (hours) to compute f of kis or the set B for large numbers. Somebody suggested that implementing this in C++ resulted in a solution in less than 10 minutes. Would C++ be a good language to learn to solve these problems, or can my Mathematica code be improved to fix the performance issues? I don't know anything about C or C++ and it should be difficult to start to learn this languages. I prefer to improve or write new code in mathematica. Problem Description Let $f$ be an arithmetic function and A={k1,k2,...,kn} are integers in increasing order. Now I want to start with k1 and compare f(ki) with f(k1). If f(ki)f(k1), put ki as k1. Now start with ki, and compare f(kj) with f(ki), for ji. If f(kj)f(ki), put kj as ki, and repeat this procedure. At the end we will have a sub sequence B={L1,...,Lm} of A by this property: f(L(i+1))f(L(i)), for any 1<=i<=m-1 For example, let f is the divisor function of integers. Here I put some part of my code and this is just a sample and the question in my program could be more larger than these: «««««««««««««««««««««««««««««««««««« f[n_] := DivisorSigma[0, n]; g[n_] := Product[Prime[i], {i, 1, PrimePi[n]}]; k1 = g[67757] g[353] g[59] g[19] g[11] g[7] g[5]^2 6^3 2^7; k2 = g[67757] g[353] g[59] g[19] g[11] g[7] g[5] 6^5 2^7; k3 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^4 2^7; k4 = g[67759] g[349] g[53] g[19] g[11] g[7] g[5] 6^5 2^6; k5 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^4 2^8; k6 = g[67759] g[349] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^7; k7 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^5 2^6; k8 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^4 2^9; k9 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^7; k10 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^5 2^7; k11 = g[67759] g[349] g[53] g[19] g[11] g[7] g[5]^2 6^4 2^6; k12 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^8; k13 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^4 2^6; k14 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^9; k15 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^4 2^7; k16 = g[67757] g[359] g[53] g[23] g[11] g[7] g[5] 6^4 2^8; k17 = g[67757] g[359] g[59] g[19] g[11] g[7] g[5] 6^4 2^7; k18 = g[67757] g[359] g[53] g[23] g[11] g[7] g[5] 6^4 2^9; k19 = g[67759] g[353] g[53] g[19] g[11] g[7] g[5] 6^4 2^6; k20 = g[67763] g[347] g[53] g[19] g[11] g[7] g[5] 6^4 2^7; k = Table[k1, k2, k3, k4, k5, k6, k7, k8, k9, k10, k11, k12, k13, k14, k15, k16, k17, k18, k19, k20]; i = 1; count = 0; For[j = i, j <= 20, j++, If[f[k[[j]]] - f[k[[i]]] > 0, i = j; Print["k",i]; count = count + 1]]; Print["count= ", count] ««««««««««««««««««««««««««««««««««««

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• Advice on refactoring PHP Project

  - by b0x

  I have a small SAS ERP that was written some years ago using PHP. At that time, it didn't use any framework, but the code isn't a mess. Nowadays, the project grows and I’m now working with 3 more programmers. Often, they ask to me why we don’t migrate to a framework such as Laravel. Although I'd love trying Laravel, I’m a small business and I don't have time nor money to stop and spend a whole year building everything from scratch. I need to live and pay the bills. So, I've read a lot about this matter, and I decided that doing a refactoring is the best way to do it. Also, I'm not so sure that a framework will make things easy. Business goals are: Make the code easier to new hired programmers Separate the "view", in order to: release different versions of this product (using the same code), but under different brands and websites at the minimum cost (just changing view) release different versions to fit mobile/tablet. Make different types of this product, selling packages as if they were plugins. Develop custom packages for some costumers (like plugins/addon's that they can buy to put on the main application). Code goals: Introduce best pratices, standards for everyone Try to build my own MVC structure Improve validation of data/forms (today they are mixed in both ajax and classes) Create automated testing routines for quality assurance. My current structure project: class\ extra\ hd\ logs\ public_html\ public_html\includes\ public_html\css|js|images\ class\ There are three types of classes. They are all “autoloaded” with something similar with PSR-0, but I don’t use namespaces. 1. class.Something.php Connects to Database using specific methods. I.e: Costumer-list(); It uses “class.Db.php”, that it’s an abstraction of mysql on every method. 2. class.SomethingProc.php Do things that “join” things that come from “class.Something.php”. Like IF/ELSE, math operations. 3. class.SomethingHTML.php The classes with “HTML” suffix implements only static methods and HTML code only. A real life example: All the programmers need to use $cSomething ($c to class) and $arrSomething (to array). Costumer.php (view) <?php $cCosumter = new Costumer(); $arrCostumer = $cCostumer->list(); echo CostumerHTML::table($arrCostumer); ?> Extra\ Store 3rdparty projects/classes from others, such MPDF, PHPMailer, etc. Hd\ Store user’s files outsite wwwroot dir. Logs\ Store phplogs and the system itself logs (We have a static Log::error() method, that we put in every method of every class) Public_html\ Stores the files that people use. Public_html\includes\ Store the main “config.php” file and all files that do “ajax things” ajax.Costumer.php, for example. Help is needed ;) So, as you can see we have some standards, and also for database things. But I want to write a manual of our rules. Something that I can give to any new programmer at my company and he can go on. This is not totally a mess, but it could be better seeing the new practices. What could I do to separate this as MVC, to have multiple views. Could you give me some tips considering my goals? Keep im mind the different products/custom things for specific costumers without breaking the main application. URL for tutorials, books, etc, would be nice.

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• Caching factory design

  - by max

  I have a factory class XFactory that creates objects of class X. Instances of X are very large, so the main purpose of the factory is to cache them, as transparently to the client code as possible. Objects of class X are immutable, so the following code seems reasonable: # module xfactory.py import x class XFactory: _registry = {} def get_x(self, arg1, arg2, use_cache = True): if use_cache: hash_id = hash((arg1, arg2)) if hash_id in _registry: return _registry[hash_id] obj = x.X(arg1, arg2) _registry[hash_id] = obj return obj # module x.py class X: # ... Is it a good pattern? (I know it's not the actual Factory Pattern.) Is there anything I should change? Now, I find that sometimes I want to cache X objects to disk. I'll use pickle for that purpose, and store as values in the _registry the filenames of the pickled objects instead of references to the objects. Of course, _registry itself would have to be stored persistently (perhaps in a pickle file of its own, in a text file, in a database, or simply by giving pickle files the filenames that contain hash_id). Except now the validity of the cached object depends not only on the parameters passed to get_x(), but also on the version of the code that created these objects. Strictly speaking, even a memory-cached object could become invalid if someone modifies x.py or any of its dependencies, and reloads it while the program is running. So far I ignored this danger since it seems unlikely for my application. But I certainly cannot ignore it when my objects are cached to persistent storage. What can I do? I suppose I could make the hash_id more robust by calculating hash of a tuple that contains arguments arg1 and arg2, as well as the filename and last modified date for x.py and every module and data file that it (recursively) depends on. To help delete cache files that won't ever be useful again, I'd add to the _registry the unhashed representation of the modified dates for each record. But even this solution isn't 100% safe since theoretically someone might load a module dynamically, and I wouldn't know about it from statically analyzing the source code. If I go all out and assume every file in the project is a dependency, the mechanism will still break if some module grabs data from an external website, etc.). In addition, the frequency of changes in x.py and its dependencies is quite high, leading to heavy cache invalidation. Thus, I figured I might as well give up some safety, and only invalidate the cache only when there is an obvious mismatch. This means that class X would have a class-level cache validation identifier that should be changed whenever the developer believes a change happened that should invalidate the cache. (With multiple developers, a separate invalidation identifier is required for each.) This identifier is hashed along with arg1 and arg2 and becomes part of the hash keys stored in _registry. Since developers may forget to update the validation identifier or not realize that they invalidated existing cache, it would seem better to add another validation mechanism: class X can have a method that returns all the known "traits" of X. For instance, if X is a table, I might add the names of all the columns. The hash calculation will include the traits as well. I can write this code, but I am afraid that I'm missing something important; and I'm also wondering if perhaps there's a framework or package that can do all of this stuff already. Ideally, I'd like to combine in-memory and disk-based caching.

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• Investigating on xVelocity (VertiPaq) column size

  - by Marco Russo (SQLBI)

    In January I published an article about how to optimize high cardinality columns in VertiPaq. In the meantime, VertiPaq has been rebranded to xVelocity: the official name is now “xVelocity in-memory analytics engine (VertiPaq)” but using xVelocity and VertiPaq when we talk about Analysis Services has the same meaning. In this post I’ll show how to investigate on columns size of an existing Tabular database so that you can find the most important columns to be optimized. A first approach can be looking in the DataDir of Analysis Services and look for the folder containing the database. Then, look for the biggest files in all subfolders and you will find the name of a file that contains the name of the most expensive column. However, this heuristic process is not very optimized. A better approach is using a DMV that provides the exact information. For example, by using the following query (open SSMS, open an MDX query on the database you are interested to and execute it) you will see all database objects sorted by used size in a descending way. SELECT * FROM $SYSTEM.DISCOVER_STORAGE_TABLE_COLUMN_SEGMENTS ORDER BY used_size DESC You can look at the first rows in order to understand what are the most expensive columns in your tabular model. The interesting data provided are: TABLE_ID: it is the name of the object – it can be also a dictionary or an index COLUMN_ID: it is the column name the object belongs to – you can also see ID_TO_POS and POS_TO_ID in case they refer to internal indexes RECORDS_COUNT: it is the number of rows in the column USED_SIZE: it is the used memory for the object By looking at the ration between USED_SIZE and RECORDS_COUNT you can understand what you can do in order to optimize your tabular model. Your options are: Remove the column. Yes, if it contains data you will never use in a query, simply remove the column from the tabular model Change granularity. If you are tracking time and you included milliseconds but seconds would be enough, round the data source column to the nearest second. If you have a floating point number but two decimals are good enough (i.e. the temperature), round the number to the nearest decimal is relevant to you. Split the column. Create two or more columns that have to be combined together in order to produce the original value. This technique is described in VertiPaq optimization article. Sort the table by that column. When you read the data source, you might consider sorting data by this column, so that the compression will be more efficient. However, this technique works better on columns that don’t have too many distinct values and you will probably move the problem to another column. Sorting data starting from the lower density columns (those with a few number of distinct values) and going to higher density columns (those with high cardinality) is the technique that provides the best compression ratio. After the optimization you should be able to reduce the used size and improve the count/size ration you measured before. If you are interested in a longer discussion about internal storage in VertiPaq and you want understand why this approach can save you space (and time), you can attend my 24 Hours of PASS session “VertiPaq Under the Hood” on March 21 at 08:00 GMT.

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• [EF + ORACLE] Updating and Deleting Entities

  - by JTorrecilla

  Prologue In previous chapters we have seen how to insert data through EF, with and without sequences. In this one, we are going to see how to Update and delete Data from the DB. Updating data The update of the Entity Data (properties) is a very common and easy action. Before of change any of the properties of the Entity, we can check the EntityState property, and we can see that is EntityState.Unchanged.   For making an update it is needed to get the Entity which will be modified. In the following example, I use the GetEmployeeByNumber to get a valid Entity: 1: EMPLEADOS emp=GetEmployeeByNumber(2); 2: emp.Name="a"; 3: emp.Phone="2"; 4: emp.Mail="aa"; After modifying the desired properties of the Entity, we are going to check again Entitystate property, which now has the EntityState.Modified value. To persist the changes to the DB is necessary to invoke the SaveChanges function of our context. 1: context.SaveChanges(); After modifying the desired properties of the Entity, we are going to check again Entitystate property, which now has the EntityState.Modified value. To persist the changes to the DB is necessary to invoke the SaveChanges function of our context. If we check again the EntityState property we will see that the value will be EntityState.Unchanged.   Deleting Data Another easy action is to delete an Entity.   The first step to delete an Entity from the DB is to select the entity: 1: CLIENTS selectedClient = GetClientByNumber(15); 2: context.CLIENTES.DeleteObject(clienteSeleccionado); Before invoking the DeleteObject function, we will check EntityStet which value must be EntityState.Unchanged. After deleting the object, the state will be changed to EntitySate.Deleted. To commit the action we have to invoke the SaveChanges function. Aftar that, the EntityState property will be EntityState.Detached. Cascade Entity Framework lets cascade updates and deletes, although I never see cascade updates. What is a cascade delete? A cascade delete is an action that allows to delete all the related object to the object we desire to delete. This option could be established in the DB manager, or it could be in the EF model designer. For example: With a given relation (1-N) between clients and requests. The common situation must be to let delete those clients whose have no requests. If we select the relation between both entities, and press the second mouse button, we can see the properties panel of the relation. The props are: This grid shows the relations indicating the Master table(Clients) and the end point (Cabecera or Requests) The property “End 1 OnDelete” indicates the action to do when a Entity from the Master will be deleted. There are two options: - None: No action will be done, it is said, if a Entity has details entities it could not be deleted. - Cascade: It will delete all related entities to the master Entity. If we enable the cascade delete in a relation, and we invoke the DeleteObject function of the set, we could observe that all the related object indicates a Entitystate.Deleted state. Like an update, insert or common delete, until we commit the changes with SaveChanges function, the data would not be commited. Si habilitamos el borrado en cascada de una relación, e invocamos a la función DeleteObject del conjunto, podremos observar que todas las entidades de Detalle (de la relación indicada) presentan el valor EntityState.Deleted en la propiedad EntityState. Del mismo modo que en el borrado, inserción o actualización, hasta que no se invoque al método SaveChanges, los cambios no van a ser confirmados en la Base de Datos. Finally In this chapter we have seen how to update a Entity, how to delete an Entity and how to implement Cascade Deleting through EF. In next chapters we will see how to query the DB data.

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• Do Great Work

  - by user12601034

  Have you ever attended an online conference and actually had a desire to attend all of it?? Yesterday I attended the first day of the Great Work MBA program, sponsored by Box of Crayons and hosted by Michael Bungay Stanier. The topic of the day was “Grounding Yourself,” and the day featured five speakers on five different topics. I have to admit that I started the first session with kind of a “blech” feeling that I didn’t really want to participate, but for some reason I did. So I listened to the first session, and I was hooked. I ended up listening to all of the sessions for the day, and I had some great take-aways from the sessions – my highlights included: The opposite of bravery isn’t fear, it’s settling. In essence, you need to be brave in order to accomplish anything. If you’re settling, you’re not being brave, and your accomplishments will likely be lackluster. Bravery requires confidence and permission. You need to work at being brave by taking small wins, build them up and then take slightly larger risks. Additionally, you need to “claim your own crown.” Nobody in the business world is going to give you permission to be a guru in X – you need to give yourself permission to become a guru in X and then do it. Fall in love with obstacles. Everyone is going to face some form of failure. One way to deal with this is to fall in love with solving the puzzle of obstacles. You don’t have to hit it if you can go around it. Understanding purpose brings out the best in people and the best people. As a leader, drawing in people who are passionate and highly motivated about their work creates velocity for your organization. Being clear about purpose is the first step in doing this. You must own your own story. Everything about you creates a “unique you” that is distinct from everyone else. As you take ownership of this, it becomes part of your strength. It’s not a strength if you’re running away from it. Focus on what’s right. Be aware of your tendency to interpret a situation a certain way and differentiate between helpful and unhelpful interpretations. Three questions for how to think differently: 1) Why? 2) Who says so? 3) What would happen if? These three questions can help you build alternative perspectives and options that can increase resiliency. Even though this first day was focused on “Grounding Yourself,” I see plenty of application in the corporate environment for both individuals and leaders of teams. To apply these highlights to my work environment, I would do the following: Understand the purpose – of my company, of my team and of my role on the team. If I know the purpose, I know what I need to bring to the table to make me, my team and my company successful. Declare your goals…your BEHAGS (big, hairy, audacious goals).Have the confidence to declare what you and/or your team is going to accomplish.Sure, you might have to re-state those goals down the line, but you can learn from that as well. Get creative about achieving your goals.Break down your obstacles by asking yourself what is going to stop you from achieving your goals and then, for each obstacles, ask those three questions:Why?Who says so? What would happen if? Focus on what’s right.I had a manager who asked us to write status reports every week.“Status” consisted of 1) What did I accomplish; 2) What will I accomplish next week; 3) How can my manager help me.The focus on our status report was always “what’s right”(“what’s wrong” was always a conversation at the point in time it was needed). I’m normally a skeptic of online webcasts/conferences, and I normally expect to take away maybe one or two ideas. I’m really glad, however, that I took the time to listen to all of the sessions yesterday, and I hope that my take-aways inspire you to think about how you might do great work also. --

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• Removing occurrences of characters in a string

  - by DmainEvent

  I am reading this book, programming Interviews exposed by John Wiley and sons and in chapter 6 they are discussing removing all instances of characters in a src string using a removal string... so removeChars(string str, string remove) In there writeup they sey the steps to accomplish this are to have a boolean lookup array with all values initially set to false, then loop through each character in remove setting the corresponding value in the lookup array to true (note: this could also be a hash if the possible character set where huge like Unicode-16 or something like that or if str and remove are both relatively small... < 100 characters I suppose). You then iterate through the str with a source and destination index, copying each character only if its corresponding value in the lookup array is false... Which makes sense... I don't understand the code that they use however... They have for(src = 0; src < len; ++src){ flags[r[src]] == true; } which is turning the flag value at the remove string indexed at src to true... so if you start out with PLEASE HELP as your str and LEA as your remove you will be setting in your flag table at 0,1,2... t|t|t but after that you will get an out of bounds exception because r doesn't have have anything greater than 2 in it... even using there example you get an out of bounds exception... Am is there code example unworkable? Entire function string removeChars( string str, string remove ){ char[] s = str.toCharArray(); char[] r = remove.toCharArray(); bool[] flags = new bool[128]; // assumes ASCII! int len = s.Length; int src, dst; // Set flags for characters to be removed for( src = 0; src < len; ++src ){ flags[r[src]] = true; } src = 0; dst = 0; // Now loop through all the characters, // copying only if they aren’t flagged while( src < len ){ if( !flags[ (int)s[src] ] ){ s[dst++] = s[src]; } ++src; } return new string( s, 0, dst ); } as you can see, r comes from the remove string. So in my example the remove string has only a size of 3 while my str string has a size of 11. len is equal to the length of the str string. So it would be 11. How can I loop through the r string since it is only size 3? I haven't compiled the code so I can loop through it, but just looking at it I know it won't work. I am thinking they wanted to loop through the r string... in other words they got the length of the wrong string here.

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• E-Business Suite : Role of CHUNK_SIZE in Oracle Payroll

  - by Giri Mandalika

  Different batch processes in Oracle Payroll flow have the ability to spawn multiple child processes (or threads) to complete the work in hand. The number of child processes to fork is controlled by the THREADS parameter in APPS.PAY_ACTION_PARAMETERS view. THREADS parameter The default value for THREADS parameter is 1, which is fine for a single-processor system but not optimal for the modern multi-core multi-processor systems. Setting the THREADS parameter to a value equal to or less than the total number of [virtual] processors available on the system may improve the performance of payroll processing. However on the down side, since multiple child processes operate against the same set of payroll tables in HR schema, database may experience undesired consequences such as buffer busy waits and index contention, which results in giving up some of the gains achieved by using multiple child processes/threads to process the work. Couple of other action parameters, CHUNK_SIZE and CHUNK_SHUFFLE, help alleviate the database contention. eg., Set a value for THREADS parameter as shown below. CONNECT APPS/APPS_PASSWORD UPDATE PAY_ACTION_PARAMETERS SET PARAMETER_VALUE = DESIRED_VALUE WHERE PARAMETER_NAME = 'THREADS'; COMMIT; (I am not aware of any maximum value for THREADS parameter) CHUNK_SIZE parameter The size of each commit unit for the batch process is controlled by the CHUNK_SIZE action parameter. In other words, chunking is the act of splitting the assignment actions into commit groups of desired size represented by the CHUNK_SIZE parameter. The default value is 20, and each thread processes one chunk at a time -- which means each child process inserts or processes 20 assignment actions at any time. When multiple threads are configured, each thread picks up a chunk to process, completes the assignment actions and then picks up another chunk. This is repeated until all the chunks are exhausted. It is possible to use different chunk sizes in different batch processes. During the initial phase of processing, CHUNK_SIZE number of assignment actions are inserted into relevant table(s). When multiple child processes are inserting data at the same time into the same set of tables, as explained earlier, database may experience contention. The default value of 20 is mostly optimal in such a case. Experiment with different values for the initial phase by +/-10 for CHUNK_SIZE parameter and observe the performance impact. A larger value may make sense during the main processing phase. Again experimentation is the key in finding the suitable value for your environment. Start with a large value such as 2000 for the chunk size, then increment or decrement the size by 500 at a time until an optimal value is found. eg., Set a value for CHUNK_SIZE parameter as shown below. CONNECT APPS/APPS_PASSWORD UPDATE PAY_ACTION_PARAMETERS SET PARAMETER_VALUE = DESIRED_VALUE WHERE PARAMETER_NAME = 'CHUNK_SIZE'; COMMIT; CHUNK_SIZE action parameter accepts a value that is as low as 1 or as high as 16000. CHUNK SHUFFLE parameter By default, chunks of assignment actions are processed sequentially by all threads - which may not be a good thing especially given that all child processes/threads performing similar actions against the same set of tables almost at the same time. By saying not a good thing, I mean to say that the default behavior leads to contention in the database (in data blocks, for example). It is possible to relieve some of that database contention by randomizing the processing order of chunks of assignment actions. This behavior is controlled by the CHUNK SHUFFLE action parameter. Chunk processing is not randomized unless explicitly configured. eg., Set chunk shuffling as shown below. CONNECT APPS/APPS_PASSWORD UPDATE PAY_ACTION_PARAMETERS SET PARAMETER_VALUE = 'Y' WHERE PARAMETER_NAME = 'CHUNK SHUFFLE'; COMMIT; Finally I recommend checking the following document out for additional details and additional pay action tunable parameters that may speed up the processing of Oracle Payroll.     My Oracle Support Doc ID: 226987.1 Oracle 11i & R12 Human Resources (HRMS) & Benefits (BEN) Tuning & System Health Checks Also experiment with different combinations of parameters and values until the right set of action parameters and values are found for your deployment.

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