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  • Session Report: What’s New in JSF: A Complete Tour of JSF 2.2

    - by Janice J. Heiss
    On Wednesday, Ed Burns, Consulting Staff Member at Oracle, presented a session, CON3870 -- “What’s New in JSF: A Complete Tour of JSF 2.2,” in which he provided an update on recent developments in JavaServer Faces 2.2. He began by emphasizing that, “JavaServer Faces 2.2 continues the evolution of the Java EE standard user interface technology. Like previous releases, this iteration is very community-driven and transparent.” He pointed out that since JSF was introduced at the 2001 JavaOne Keynote, it has had a long and successful run and has found a home in applications where the UI logic resides entirely on the server where the model and UI logic is. In such cases, the browser performs fairly simple functions. However, developers can take advantage of the power of browsers, something that Project Avatar is focused on by letting developers author their applications so the UI logic is running on the client and communicating to the back end via RESTful web services. “Most importantly,” remarked Burns, “JSF 2.2 offers a really good migration path because even in the scope of one application you could have an app written with JSF that has its UI logic on the server and, on a gradual basis, you could migrate parts of the app over to use client-side technologies. This can be done at any level of granularity – per page or per collection of pages. It all depends on what you want to do.” His presentation, which focused on the basic new features of JSF 2.2, began by restating the scope of JSF and encouraged attendees to check out Roger Kitain’s session: CON5133 “Techniques for Responsive Real-Time Web UIs.” Burns explained that JSF has endured because, “We still need web apps that are maintainable, localizable, quick to build, accessible, secure, look great and are fun to use.” It is used on every continent – the curious can go here to check out where its unofficial usage is tracked. He emphasized the significance of the UI logic being substantially on the server. This: Separates Component Semantics from Rendering, Allows components to “own” their little patch of the UI -- encode/decode, And offers a well-defined lifecycle: Inversion of Control. Burns reminded attendees that JSR-344, the spec for JSF 2.2, is now on Java Community Process 2.8, a revised version of the JCP that allows for more openness and transparency. He then offered some tools for community access to JSF 2.2:    * Public java.net projects spec http://jsf-spec.java.net/ impl http://jsf.java.net/ Open Source: GPL+Classpath Exception    * Mailing Lists [email protected]                                Public readable archive, JSPA signed member read/write [email protected]                                     Public readable archive, any java.net member read/write                         All mail sent to jsr344-experts is sent to users. * Issue Tracker spec http://jsf-spec.java.net/issues/ impl http://jsf.java.net/issues/ JSF 2.2, which is JSR 344, has a Public Review Draft planned by December 2012 with no need for a Renewal Ballot. The Early Draft Review of JSR 344 was published on December 8, 2011. Interested developers are encouraged to offer their input. Six Big Ticket Features of JSF 2.2 Burns summarized the six big ticket features of JSF 2.2:* HTML5 Friendly Markup Support Pass through attributes and elements * Faces Flows* Cross Site Request Forgery Protection* Loading Facelets via ResourceHandler* File Upload Component* Multi-Templating He explained that he called it “HTML 5 friendly” because there is really nothing HTML 5 specific about it -- it could be 4. But it enables developers to use new elements that are present in HTML5 without having a JSF component library that is written to take advantage of those specifically. It gives the page author the ability to use plain HTML5 to write their page, but to still take advantage of the server-side available in JSF. He presented a demo showing JSF 2.2’s ability to leverage the expressiveness of HTML5. Burns then explained the significance of face flows, which offer function points and quantify how much work has taken place, something of great value to JSF users. He went on to talk about JSF 2.2.’s cross-site request forgery protection (CSRF) and offered details about how it protects applications against attack. Then he talked about JSF 2.2’s File Upload Component and explained that the final specification will have Ajax and non-Ajax support. The current milestone has non-Ajax support implemented. He then went on to explain its capacity to add facelets through ResourceHandler. Previously, JSF 2.0 added Facelets and ResourceHandler as disparate units; now in JSF 2.2 the two concepts are unified. Finally, he explained the concept of multi-templating in JSF 2.2 and went on to discuss more medium-level features of the release. For an easy, low maintenance way of staying in touch with JSF developments go to JSF’s Twitter page where every month or so, important updates are offered.

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  • “Being Agile” Means No Documentation, Right?

    - by jesschadwick
    Ask most software professionals what Agile is and they’ll probably start talking about flexibility and delivering what the customer wants.  Some may even mention the word “iterations”.  But inevitably, they’ll say at some point that it means less or even no documentation.  After all, doesn’t creating, updating, and circulating painstakingly comprehensive documentation that everyone and their mother have officially signed off on go against the very core of Agile?  Of course it does!  But really, they’re missing the point! Read The Agile Manifesto. (No, seriously - read it now. It’s short. I’ll wait.)  It’s essentially a list of values.  More specifically, it’s a right-side/left-side weighted list of values:  “Value this over that”. Many people seem to get the impression that this is really a “good vs. bad” list and that those values on the right side are evil and should essentially be tossed on the floor.  This leads to the conclusion that in order to be Agile we must throw away our fancy expensive tools, document as little as possible, and scoff at the idea of a project plan.  This conclusion is quite convenient because it essentially means “less work, more productivity!” (particularly in regards to the documentation and project planning).  I couldn’t disagree with this conclusion more. My interpretation of the Manifesto targets “over” as the operative word.  It’s not just a list of right vs. wrong or good vs. bad.  It’s a list of priorities.  In other words, none of the concepts on the list should be removed from your development lifecycle – they are all important… just not equally important.  This is not a unique interpretation, in fact it says so right at the end of the manifesto! So, the next time your team sits down to tackle that big new project, don’t make the first order of business to outlaw all meetings, documentation, and project plans.  Instead, collaborate with both your team and the business members involved (you do have business members sitting in the room, directly involved in the project planning, right?) and determine the bare minimum that will allow all of you to work and communicate in the best way possible.  This often means that you can pick and choose which parts of the Agile methodologies and process work for your particular project and end up with an amalgamation of Waterfall, Agile, XP, SCRUM and whatever other methodologies the members of your team have been exposed to (my favorite is “SCRUMerfall”). The biggest implication of this is that there is no one way to implement Agile.  There is no checklist with which you can tick off boxes and confidently conclude that, “Yep, we’re Agile™!”  In fact, depending on your business and the members of your team, moving to Agile full-bore may actually be ill-advised.  Such a drastic change just ends up taking everyone out of their comfort zone which they inevitably fall back into by the end of the project.  This often results in frustration to the point that Agile is abandoned altogether because “we just need to ship something!”  Needless to say, this is far more devastating to a project. Instead, I offer this approach: keep it simple and take it slow.  If your business members or customers are only involved at the beginning phases and nowhere to be seen until the project is delivered, invite them to your daily meetings; encourage them to keep up to speed on what’s going on on a daily basis and provide feedback.  If your current process is heavy on the documentation, try to reduce it as opposed to eliminating it outright.  If you need a “TPS Change Request” signed in triplicate with a 5-day “cooling off period” before a change is implemented, try a simple bug tracking system!  Tighten the feedback loop! Finally, at the end of every “iteration” (whatever that means to you, as long as it’s relatively frequent), take as much time as you can spare (even if it’s an hour or so) and perform some kind of retrospective.  Learn from your mistakes.  Figure out what’s working for you and what’s not, then fix it.  Before you know it you’ve got a handful of iterations and/or projects under your belt and you sit down with your team to realize that, “Hey, this is working - we’re pretty Agile!”  After all, Agile is a Zen journey.  It’s a destination that you aim for, not force, and even if you never reach true “enlightenment” that doesn’t mean your team can’t be exponentially better off from merely taking the journey.

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  • Toorcon14

    - by danx
    Toorcon 2012 Information Security Conference San Diego, CA, http://www.toorcon.org/ Dan Anderson, October 2012 It's almost Halloween, and we all know what that means—yes, of course, it's time for another Toorcon Conference! Toorcon is an annual conference for people interested in computer security. This includes the whole range of hackers, computer hobbyists, professionals, security consultants, press, law enforcement, prosecutors, FBI, etc. We're at Toorcon 14—see earlier blogs for some of the previous Toorcon's I've attended (back to 2003). This year's "con" was held at the Westin on Broadway in downtown San Diego, California. The following are not necessarily my views—I'm just the messenger—although I could have misquoted or misparaphrased the speakers. Also, I only reviewed some of the talks, below, which I attended and interested me. MalAndroid—the Crux of Android Infections, Aditya K. Sood Programming Weird Machines with ELF Metadata, Rebecca "bx" Shapiro Privacy at the Handset: New FCC Rules?, Valkyrie Hacking Measured Boot and UEFI, Dan Griffin You Can't Buy Security: Building the Open Source InfoSec Program, Boris Sverdlik What Journalists Want: The Investigative Reporters' Perspective on Hacking, Dave Maas & Jason Leopold Accessibility and Security, Anna Shubina Stop Patching, for Stronger PCI Compliance, Adam Brand McAfee Secure & Trustmarks — a Hacker's Best Friend, Jay James & Shane MacDougall MalAndroid—the Crux of Android Infections Aditya K. Sood, IOActive, Michigan State PhD candidate Aditya talked about Android smartphone malware. There's a lot of old Android software out there—over 50% Gingerbread (2.3.x)—and most have unpatched vulnerabilities. Of 9 Android vulnerabilities, 8 have known exploits (such as the old Gingerbread Global Object Table exploit). Android protection includes sandboxing, security scanner, app permissions, and screened Android app market. The Android permission checker has fine-grain resource control, policy enforcement. Android static analysis also includes a static analysis app checker (bouncer), and a vulnerablity checker. What security problems does Android have? User-centric security, which depends on the user to grant permission and make smart decisions. But users don't care or think about malware (the're not aware, not paranoid). All they want is functionality, extensibility, mobility Android had no "proper" encryption before Android 3.0 No built-in protection against social engineering and web tricks Alternative Android app markets are unsafe. Simply visiting some markets can infect Android Aditya classified Android Malware types as: Type A—Apps. These interact with the Android app framework. For example, a fake Netflix app. Or Android Gold Dream (game), which uploads user files stealthy manner to a remote location. Type K—Kernel. Exploits underlying Linux libraries or kernel Type H—Hybrid. These use multiple layers (app framework, libraries, kernel). These are most commonly used by Android botnets, which are popular with Chinese botnet authors What are the threats from Android malware? These incude leak info (contacts), banking fraud, corporate network attacks, malware advertising, malware "Hackivism" (the promotion of social causes. For example, promiting specific leaders of the Tunisian or Iranian revolutions. Android malware is frequently "masquerated". That is, repackaged inside a legit app with malware. To avoid detection, the hidden malware is not unwrapped until runtime. The malware payload can be hidden in, for example, PNG files. Less common are Android bootkits—there's not many around. What they do is hijack the Android init framework—alteering system programs and daemons, then deletes itself. For example, the DKF Bootkit (China). Android App Problems: no code signing! all self-signed native code execution permission sandbox — all or none alternate market places no robust Android malware detection at network level delayed patch process Programming Weird Machines with ELF Metadata Rebecca "bx" Shapiro, Dartmouth College, NH https://github.com/bx/elf-bf-tools @bxsays on twitter Definitions. "ELF" is an executable file format used in linking and loading executables (on UNIX/Linux-class machines). "Weird machine" uses undocumented computation sources (I think of them as unintended virtual machines). Some examples of "weird machines" are those that: return to weird location, does SQL injection, corrupts the heap. Bx then talked about using ELF metadata as (an uintended) "weird machine". Some ELF background: A compiler takes source code and generates a ELF object file (hello.o). A static linker makes an ELF executable from the object file. A runtime linker and loader takes ELF executable and loads and relocates it in memory. The ELF file has symbols to relocate functions and variables. ELF has two relocation tables—one at link time and another one at loading time: .rela.dyn (link time) and .dynsym (dynamic table). GOT: Global Offset Table of addresses for dynamically-linked functions. PLT: Procedure Linkage Tables—works with GOT. The memory layout of a process (not the ELF file) is, in order: program (+ heap), dynamic libraries, libc, ld.so, stack (which includes the dynamic table loaded into memory) For ELF, the "weird machine" is found and exploited in the loader. ELF can be crafted for executing viruses, by tricking runtime into executing interpreted "code" in the ELF symbol table. One can inject parasitic "code" without modifying the actual ELF code portions. Think of the ELF symbol table as an "assembly language" interpreter. It has these elements: instructions: Add, move, jump if not 0 (jnz) Think of symbol table entries as "registers" symbol table value is "contents" immediate values are constants direct values are addresses (e.g., 0xdeadbeef) move instruction: is a relocation table entry add instruction: relocation table "addend" entry jnz instruction: takes multiple relocation table entries The ELF weird machine exploits the loader by relocating relocation table entries. The loader will go on forever until told to stop. It stores state on stack at "end" and uses IFUNC table entries (containing function pointer address). The ELF weird machine, called "Brainfu*k" (BF) has: 8 instructions: pointer inc, dec, inc indirect, dec indirect, jump forward, jump backward, print. Three registers - 3 registers Bx showed example BF source code that implemented a Turing machine printing "hello, world". More interesting was the next demo, where bx modified ping. Ping runs suid as root, but quickly drops privilege. BF modified the loader to disable the library function call dropping privilege, so it remained as root. Then BF modified the ping -t argument to execute the -t filename as root. It's best to show what this modified ping does with an example: $ whoami bx $ ping localhost -t backdoor.sh # executes backdoor $ whoami root $ The modified code increased from 285948 bytes to 290209 bytes. A BF tool compiles "executable" by modifying the symbol table in an existing ELF executable. The tool modifies .dynsym and .rela.dyn table, but not code or data. Privacy at the Handset: New FCC Rules? "Valkyrie" (Christie Dudley, Santa Clara Law JD candidate) Valkyrie talked about mobile handset privacy. Some background: Senator Franken (also a comedian) became alarmed about CarrierIQ, where the carriers track their customers. Franken asked the FCC to find out what obligations carriers think they have to protect privacy. The carriers' response was that they are doing just fine with self-regulation—no worries! Carriers need to collect data, such as missed calls, to maintain network quality. But carriers also sell data for marketing. Verizon sells customer data and enables this with a narrow privacy policy (only 1 month to opt out, with difficulties). The data sold is not individually identifiable and is aggregated. But Verizon recommends, as an aggregation workaround to "recollate" data to other databases to identify customers indirectly. The FCC has regulated telephone privacy since 1934 and mobile network privacy since 2007. Also, the carriers say mobile phone privacy is a FTC responsibility (not FCC). FTC is trying to improve mobile app privacy, but FTC has no authority over carrier / customer relationships. As a side note, Apple iPhones are unique as carriers have extra control over iPhones they don't have with other smartphones. As a result iPhones may be more regulated. Who are the consumer advocates? Everyone knows EFF, but EPIC (Electrnic Privacy Info Center), although more obsecure, is more relevant. What to do? Carriers must be accountable. Opt-in and opt-out at any time. Carriers need incentive to grant users control for those who want it, by holding them liable and responsible for breeches on their clock. Location information should be added current CPNI privacy protection, and require "Pen/trap" judicial order to obtain (and would still be a lower standard than 4th Amendment). Politics are on a pro-privacy swing now, with many senators and the Whitehouse. There will probably be new regulation soon, and enforcement will be a problem, but consumers will still have some benefit. Hacking Measured Boot and UEFI Dan Griffin, JWSecure, Inc., Seattle, @JWSdan Dan talked about hacking measured UEFI boot. First some terms: UEFI is a boot technology that is replacing BIOS (has whitelisting and blacklisting). UEFI protects devices against rootkits. TPM - hardware security device to store hashs and hardware-protected keys "secure boot" can control at firmware level what boot images can boot "measured boot" OS feature that tracks hashes (from BIOS, boot loader, krnel, early drivers). "remote attestation" allows remote validation and control based on policy on a remote attestation server. Microsoft pushing TPM (Windows 8 required), but Google is not. Intel TianoCore is the only open source for UEFI. Dan has Measured Boot Tool at http://mbt.codeplex.com/ with a demo where you can also view TPM data. TPM support already on enterprise-class machines. UEFI Weaknesses. UEFI toolkits are evolving rapidly, but UEFI has weaknesses: assume user is an ally trust TPM implicitly, and attached to computer hibernate file is unprotected (disk encryption protects against this) protection migrating from hardware to firmware delays in patching and whitelist updates will UEFI really be adopted by the mainstream (smartphone hardware support, bank support, apathetic consumer support) You Can't Buy Security: Building the Open Source InfoSec Program Boris Sverdlik, ISDPodcast.com co-host Boris talked about problems typical with current security audits. "IT Security" is an oxymoron—IT exists to enable buiness, uptime, utilization, reporting, but don't care about security—IT has conflict of interest. There's no Magic Bullet ("blinky box"), no one-size-fits-all solution (e.g., Intrusion Detection Systems (IDSs)). Regulations don't make you secure. The cloud is not secure (because of shared data and admin access). Defense and pen testing is not sexy. Auditors are not solution (security not a checklist)—what's needed is experience and adaptability—need soft skills. Step 1: First thing is to Google and learn the company end-to-end before you start. Get to know the management team (not IT team), meet as many people as you can. Don't use arbitrary values such as CISSP scores. Quantitive risk assessment is a myth (e.g. AV*EF-SLE). Learn different Business Units, legal/regulatory obligations, learn the business and where the money is made, verify company is protected from script kiddies (easy), learn sensitive information (IP, internal use only), and start with low-hanging fruit (customer service reps and social engineering). Step 2: Policies. Keep policies short and relevant. Generic SANS "security" boilerplate policies don't make sense and are not followed. Focus on acceptable use, data usage, communications, physical security. Step 3: Implementation: keep it simple stupid. Open source, although useful, is not free (implementation cost). Access controls with authentication & authorization for local and remote access. MS Windows has it, otherwise use OpenLDAP, OpenIAM, etc. Application security Everyone tries to reinvent the wheel—use existing static analysis tools. Review high-risk apps and major revisions. Don't run different risk level apps on same system. Assume host/client compromised and use app-level security control. Network security VLAN != segregated because there's too many workarounds. Use explicit firwall rules, active and passive network monitoring (snort is free), disallow end user access to production environment, have a proxy instead of direct Internet access. Also, SSL certificates are not good two-factor auth and SSL does not mean "safe." Operational Controls Have change, patch, asset, & vulnerability management (OSSI is free). For change management, always review code before pushing to production For logging, have centralized security logging for business-critical systems, separate security logging from administrative/IT logging, and lock down log (as it has everything). Monitor with OSSIM (open source). Use intrusion detection, but not just to fulfill a checkbox: build rules from a whitelist perspective (snort). OSSEC has 95% of what you need. Vulnerability management is a QA function when done right: OpenVas and Seccubus are free. Security awareness The reality is users will always click everything. Build real awareness, not compliance driven checkbox, and have it integrated into the culture. Pen test by crowd sourcing—test with logging COSSP http://www.cossp.org/ - Comprehensive Open Source Security Project What Journalists Want: The Investigative Reporters' Perspective on Hacking Dave Maas, San Diego CityBeat Jason Leopold, Truthout.org The difference between hackers and investigative journalists: For hackers, the motivation varies, but method is same, technological specialties. For investigative journalists, it's about one thing—The Story, and they need broad info-gathering skills. J-School in 60 Seconds: Generic formula: Person or issue of pubic interest, new info, or angle. Generic criteria: proximity, prominence, timeliness, human interest, oddity, or consequence. Media awareness of hackers and trends: journalists becoming extremely aware of hackers with congressional debates (privacy, data breaches), demand for data-mining Journalists, use of coding and web development for Journalists, and Journalists busted for hacking (Murdock). Info gathering by investigative journalists include Public records laws. Federal Freedom of Information Act (FOIA) is good, but slow. California Public Records Act is a lot stronger. FOIA takes forever because of foot-dragging—it helps to be specific. Often need to sue (especially FBI). CPRA is faster, and requests can be vague. Dumps and leaks (a la Wikileaks) Journalists want: leads, protecting ourselves, our sources, and adapting tools for news gathering (Google hacking). Anonomity is important to whistleblowers. They want no digital footprint left behind (e.g., email, web log). They don't trust encryption, want to feel safe and secure. Whistleblower laws are very weak—there's no upside for whistleblowers—they have to be very passionate to do it. Accessibility and Security or: How I Learned to Stop Worrying and Love the Halting Problem Anna Shubina, Dartmouth College Anna talked about how accessibility and security are related. Accessibility of digital content (not real world accessibility). mostly refers to blind users and screenreaders, for our purpose. Accessibility is about parsing documents, as are many security issues. "Rich" executable content causes accessibility to fail, and often causes security to fail. For example MS Word has executable format—it's not a document exchange format—more dangerous than PDF or HTML. Accessibility is often the first and maybe only sanity check with parsing. They have no choice because someone may want to read what you write. Google, for example, is very particular about web browser you use and are bad at supporting other browsers. Uses JavaScript instead of links, often requiring mouseover to display content. PDF is a security nightmare. Executible format, embedded flash, JavaScript, etc. 15 million lines of code. Google Chrome doesn't handle PDF correctly, causing several security bugs. PDF has an accessibility checker and PDF tagging, to help with accessibility. But no PDF checker checks for incorrect tags, untagged content, or validates lists or tables. None check executable content at all. The "Halting Problem" is: can one decide whether a program will ever stop? The answer, in general, is no (Rice's theorem). The same holds true for accessibility checkers. Language-theoretic Security says complicated data formats are hard to parse and cannot be solved due to the Halting Problem. W3C Web Accessibility Guidelines: "Perceivable, Operable, Understandable, Robust" Not much help though, except for "Robust", but here's some gems: * all information should be parsable (paraphrasing) * if not parsable, cannot be converted to alternate formats * maximize compatibility in new document formats Executible webpages are bad for security and accessibility. They say it's for a better web experience. But is it necessary to stuff web pages with JavaScript for a better experience? A good example is The Drudge Report—it has hand-written HTML with no JavaScript, yet drives a lot of web traffic due to good content. A bad example is Google News—hidden scrollbars, guessing user input. Solutions: Accessibility and security problems come from same source Expose "better user experience" myth Keep your corner of Internet parsable Remember "Halting Problem"—recognize false solutions (checking and verifying tools) Stop Patching, for Stronger PCI Compliance Adam Brand, protiviti @adamrbrand, http://www.picfun.com/ Adam talked about PCI compliance for retail sales. Take an example: for PCI compliance, 50% of Brian's time (a IT guy), 960 hours/year was spent patching POSs in 850 restaurants. Often applying some patches make no sense (like fixing a browser vulnerability on a server). "Scanner worship" is overuse of vulnerability scanners—it gives a warm and fuzzy and it's simple (red or green results—fix reds). Scanners give a false sense of security. In reality, breeches from missing patches are uncommon—more common problems are: default passwords, cleartext authentication, misconfiguration (firewall ports open). Patching Myths: Myth 1: install within 30 days of patch release (but PCI §6.1 allows a "risk-based approach" instead). Myth 2: vendor decides what's critical (also PCI §6.1). But §6.2 requires user ranking of vulnerabilities instead. Myth 3: scan and rescan until it passes. But PCI §11.2.1b says this applies only to high-risk vulnerabilities. Adam says good recommendations come from NIST 800-40. Instead use sane patching and focus on what's really important. From NIST 800-40: Proactive: Use a proactive vulnerability management process: use change control, configuration management, monitor file integrity. Monitor: start with NVD and other vulnerability alerts, not scanner results. Evaluate: public-facing system? workstation? internal server? (risk rank) Decide:on action and timeline Test: pre-test patches (stability, functionality, rollback) for change control Install: notify, change control, tickets McAfee Secure & Trustmarks — a Hacker's Best Friend Jay James, Shane MacDougall, Tactical Intelligence Inc., Canada "McAfee Secure Trustmark" is a website seal marketed by McAfee. A website gets this badge if they pass their remote scanning. The problem is a removal of trustmarks act as flags that you're vulnerable. Easy to view status change by viewing McAfee list on website or on Google. "Secure TrustGuard" is similar to McAfee. Jay and Shane wrote Perl scripts to gather sites from McAfee and search engines. If their certification image changes to a 1x1 pixel image, then they are longer certified. Their scripts take deltas of scans to see what changed daily. The bottom line is change in TrustGuard status is a flag for hackers to attack your site. Entire idea of seals is silly—you're raising a flag saying if you're vulnerable.

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  • Connecting to DB2 from SSIS

    - by Christopher House
    The project I'm currently working on involves moving various pieces of data from a legacy DB2 environment to some SQL Server and flat file locations.  Most of the data flows are real time, so they were a natural fit for the client's MQSeries on their iSeries servers and BizTalk to handle the messaging.  Some of the data flows, however, are daily batch type transmissions.  For the daily batch transmissions, it was decided that we'd use SSIS to pull the data direct from DB2 to either a SQL Server or flat file.  I'm not at all an SSIS guy, I've done a bit here and there, but mainly for situations were we needed to move data from a dev environment to QA, mostly informal stuff like that.  And, as much as I'm not an SSIS guy, I'm even less a DB2/iSeries guy.  Prior to this engagement, my knowledge of DB2 was limited to the fact that it's an IBM product and that it was probably a DBMS flatform (that's what the DB in DB2 means, right?).   One of my first goals when I came onto this project was to develop of POC SSIS package to pull some data from DB2 and dump it to a flat file.  It sounded like a pretty straight forward task.  As always, the devil is in the details.  Configuring the DB2 connection manager took a bit of trial and error.  As such, I thought I'd post my experiences here in hopes that they might save someone the efforts I went through.  That being said, please keep in mind, as I pointed out, I'm not at all a DB2 guy, so my terminology and explanations may not be 100% spot on. Before you get started, you need to figure out how you're going to connect to DB2.  From the research I did, it looks like there are a few options.  IBM has both an OLE DB and .Net data provider which can be found here.  I installed their client access tools and tried to use both the .Net and OLE DB providers but I received an error message from both when attempting to connect to the iSeries that indicated I needed a license for a product called DB2 Connect.  I inquired with one of my client's iSeries resources about a license for this product and it appears they didn't have one, so that meant the IBM drivers were out.  The other option that I found quite a bit of discussion around was Microsoft's OLE DB Provider for DB2.  This driver is part of the feature pack for SQL Server 2008 Enterprise Edition and can be downloaded here. As it turns out, I already had Microsoft's driver installed on my dev VM, which stuck me as odd since I hadn't installed it.  I discovered that the driver is installed with the BizTalk adapter pack for host systems, which was also installed on my VM.  However, it looks like the version used by the adapter pack is newer than the version provided in the SQL Server feature pack.   Once you get the driver installed, create a connection manager in your package just like you normally would and select the Microsoft OLE DB Provider for DB2 from the list of available drivers. After you select the driver, you'll need to enter in your host name, login credentials and initial catalog. A couple of things to note here.  First, the Initial catalog needs to be the same as your host name.  Not sure why that is, but trust me, it just does.  Second, for credentials, in my environment, we're using what the client's iSeries people refer to as "profiles".  I guess this is similar to SQL auth in the SQL Server world.  In other words, they've given me a username and password for connecting to DB, so I've entered it here. Next, click the Data Links button.  On the Data Links screen, enter your package collection on the first tab. Package collection is one of those DB2 concepts I'm still trying to figure out.  From the little bit I've read, packages are used to control SQL compilation and each DB2 connection needs one.  The package collection, I believe, controls where your package is created.  One of the iSeries folks I've been working with told me that I should always use QGPL for my package collection, as QGPL is "general purpose" and doesn't require any additional authority. Next click the ellipsis next to the Network drop-down.  Here you'll want to enter your host name again. Again, not sure why you need to do this, but trust me, my connection wouldn't work until I entered my hostname here. Finally, go to the Advanced tab, select your DBMS platform and check Process binary as character. My environment is DB2 on the iSeries and iSeries is the replacement for AS/400, so I selected DB2/AS400 for my platform.  Process binary as character was necessary to handle some of the DB2 data types.  I had a few columns that showed all their data as "System.Byte[]".  Checking Process binary as character resolved this. At this point, you should be good to go.  You can go back to the Connection tab on the Data Links dialog to perform a couple of tests to validate your configuration.  The Test Connection button is obvious, this just verifies you can connect to the host using the configuration data you've entered.  The Packages button will attempt to connect to the host and create the packages required to execute queries. This isn't meant to be a comprehensive look SSIS and DB2, these are just some of the notes I've come up with since I've started working with DB2 and SSIS.  I'm sure as I continue developing my packages, I'll find more quirks and will post them here.

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  • Ternary operator in VB.NET

    - by Jalpesh P. Vadgama
    We all know about Ternary operator in C#.NET. I am a big fan of ternary operator and I like to use it instead of using IF..Else. Those who don’t know about ternary operator please go through below link. http://msdn.microsoft.com/en-us/library/ty67wk28(v=vs.80).aspx Here you can see ternary operator returns one of the two values based on the condition. See following example. bool value = false;string output=string.Empty;//using If conditionif (value==true) output ="True";else output="False";//using tenary operatoroutput = value == true ? "True" : "False"; In the above example you can see how we produce same output with the ternary operator without using If..Else statement. Recently in one of the project I was working with VB.NET language and I was eager to know if there is a ternary operator equivalent there or not. After searching on internet I have found two ways to do it. IF operator which works for VB.NET 2008 and higher version and IIF operator which is there since VB 6.0. So let’s check same above example with both of this operators. So let’s create a console application which has following code. Module Module1 Sub Main() Dim value As Boolean = False Dim output As String = String.Empty ''Output using if else statement If value = True Then output = "True" Else output = "False" Console.WriteLine("Output Using If Loop") Console.WriteLine(output) output = If(value = True, "True", "False") Console.WriteLine("Output using If operator") Console.WriteLine(output) output = IIf(value = True, "True", "False") Console.WriteLine("Output using IIF Operator") Console.WriteLine(output) Console.ReadKey() End If End SubEnd Module As you can see in the above code I have written all three-way to condition check using If.Else statement and If operator and IIf operator. You can see that both IIF and If operator has three parameter first parameter is the condition which you need to check and then another parameter is true part of you need to put thing which you need as output when condition is ‘true’. Same way third parameter is for the false part where you need to put things which you need as output when condition as ‘false’. Now let’s run that application and following is the output as expected. That’s it. You can see all three ways are producing same output. Hope you like it. Stay tuned for more..Till then Happy Programming.

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  • Toorcon 15 (2013)

    - by danx
    The Toorcon gang (senior staff): h1kari (founder), nfiltr8, and Geo Introduction to Toorcon 15 (2013) A Tale of One Software Bypass of MS Windows 8 Secure Boot Breaching SSL, One Byte at a Time Running at 99%: Surviving an Application DoS Security Response in the Age of Mass Customized Attacks x86 Rewriting: Defeating RoP and other Shinanighans Clowntown Express: interesting bugs and running a bug bounty program Active Fingerprinting of Encrypted VPNs Making Attacks Go Backwards Mask Your Checksums—The Gorry Details Adventures with weird machines thirty years after "Reflections on Trusting Trust" Introduction to Toorcon 15 (2013) Toorcon 15 is the 15th annual security conference held in San Diego. I've attended about a third of them and blogged about previous conferences I attended here starting in 2003. As always, I've only summarized the talks I attended and interested me enough to write about them. Be aware that I may have misrepresented the speaker's remarks and that they are not my remarks or opinion, or those of my employer, so don't quote me or them. Those seeking further details may contact the speakers directly or use The Google. For some talks, I have a URL for further information. A Tale of One Software Bypass of MS Windows 8 Secure Boot Andrew Furtak and Oleksandr Bazhaniuk Yuri Bulygin, Oleksandr ("Alex") Bazhaniuk, and (not present) Andrew Furtak Yuri and Alex talked about UEFI and Bootkits and bypassing MS Windows 8 Secure Boot, with vendor recommendations. They previously gave this talk at the BlackHat 2013 conference. MS Windows 8 Secure Boot Overview UEFI (Unified Extensible Firmware Interface) is interface between hardware and OS. UEFI is processor and architecture independent. Malware can replace bootloader (bootx64.efi, bootmgfw.efi). Once replaced can modify kernel. Trivial to replace bootloader. Today many legacy bootkits—UEFI replaces them most of them. MS Windows 8 Secure Boot verifies everything you load, either through signatures or hashes. UEFI firmware relies on secure update (with signed update). You would think Secure Boot would rely on ROM (such as used for phones0, but you can't do that for PCs—PCs use writable memory with signatures DXE core verifies the UEFI boat loader(s) OS Loader (winload.efi, winresume.efi) verifies the OS kernel A chain of trust is established with a root key (Platform Key, PK), which is a cert belonging to the platform vendor. Key Exchange Keys (KEKs) verify an "authorized" database (db), and "forbidden" database (dbx). X.509 certs with SHA-1/SHA-256 hashes. Keys are stored in non-volatile (NV) flash-based NVRAM. Boot Services (BS) allow adding/deleting keys (can't be accessed once OS starts—which uses Run-Time (RT)). Root cert uses RSA-2048 public keys and PKCS#7 format signatures. SecureBoot — enable disable image signature checks SetupMode — update keys, self-signed keys, and secure boot variables CustomMode — allows updating keys Secure Boot policy settings are: always execute, never execute, allow execute on security violation, defer execute on security violation, deny execute on security violation, query user on security violation Attacking MS Windows 8 Secure Boot Secure Boot does NOT protect from physical access. Can disable from console. Each BIOS vendor implements Secure Boot differently. There are several platform and BIOS vendors. It becomes a "zoo" of implementations—which can be taken advantage of. Secure Boot is secure only when all vendors implement it correctly. Allow only UEFI firmware signed updates protect UEFI firmware from direct modification in flash memory protect FW update components program SPI controller securely protect secure boot policy settings in nvram protect runtime api disable compatibility support module which allows unsigned legacy Can corrupt the Platform Key (PK) EFI root certificate variable in SPI flash. If PK is not found, FW enters setup mode wich secure boot turned off. Can also exploit TPM in a similar manner. One is not supposed to be able to directly modify the PK in SPI flash from the OS though. But they found a bug that they can exploit from User Mode (undisclosed) and demoed the exploit. It loaded and ran their own bootkit. The exploit requires a reboot. Multiple vendors are vulnerable. They will disclose this exploit to vendors in the future. Recommendations: allow only signed updates protect UEFI fw in ROM protect EFI variable store in ROM Breaching SSL, One Byte at a Time Yoel Gluck and Angelo Prado Angelo Prado and Yoel Gluck, Salesforce.com CRIME is software that performs a "compression oracle attack." This is possible because the SSL protocol doesn't hide length, and because SSL compresses the header. CRIME requests with every possible character and measures the ciphertext length. Look for the plaintext which compresses the most and looks for the cookie one byte-at-a-time. SSL Compression uses LZ77 to reduce redundancy. Huffman coding replaces common byte sequences with shorter codes. US CERT thinks the SSL compression problem is fixed, but it isn't. They convinced CERT that it wasn't fixed and they issued a CVE. BREACH, breachattrack.com BREACH exploits the SSL response body (Accept-Encoding response, Content-Encoding). It takes advantage of the fact that the response is not compressed. BREACH uses gzip and needs fairly "stable" pages that are static for ~30 seconds. It needs attacker-supplied content (say from a web form or added to a URL parameter). BREACH listens to a session's requests and responses, then inserts extra requests and responses. Eventually, BREACH guesses a session's secret key. Can use compression to guess contents one byte at-a-time. For example, "Supersecret SupersecreX" (a wrong guess) compresses 10 bytes, and "Supersecret Supersecret" (a correct guess) compresses 11 bytes, so it can find each character by guessing every character. To start the guess, BREACH needs at least three known initial characters in the response sequence. Compression length then "leaks" information. Some roadblocks include no winners (all guesses wrong) or too many winners (multiple possibilities that compress the same). The solutions include: lookahead (guess 2 or 3 characters at-a-time instead of 1 character). Expensive rollback to last known conflict check compression ratio can brute-force first 3 "bootstrap" characters, if needed (expensive) block ciphers hide exact plain text length. Solution is to align response in advance to block size Mitigations length: use variable padding secrets: dynamic CSRF tokens per request secret: change over time separate secret to input-less servlets Future work eiter understand DEFLATE/GZIP HTTPS extensions Running at 99%: Surviving an Application DoS Ryan Huber Ryan Huber, Risk I/O Ryan first discussed various ways to do a denial of service (DoS) attack against web services. One usual method is to find a slow web page and do several wgets. Or download large files. Apache is not well suited at handling a large number of connections, but one can put something in front of it Can use Apache alternatives, such as nginx How to identify malicious hosts short, sudden web requests user-agent is obvious (curl, python) same url requested repeatedly no web page referer (not normal) hidden links. hide a link and see if a bot gets it restricted access if not your geo IP (unless the website is global) missing common headers in request regular timing first seen IP at beginning of attack count requests per hosts (usually a very large number) Use of captcha can mitigate attacks, but you'll lose a lot of genuine users. Bouncer, goo.gl/c2vyEc and www.github.com/rawdigits/Bouncer Bouncer is software written by Ryan in netflow. Bouncer has a small, unobtrusive footprint and detects DoS attempts. It closes blacklisted sockets immediately (not nice about it, no proper close connection). Aggregator collects requests and controls your web proxies. Need NTP on the front end web servers for clean data for use by bouncer. Bouncer is also useful for a popularity storm ("Slashdotting") and scraper storms. Future features: gzip collection data, documentation, consumer library, multitask, logging destroyed connections. Takeaways: DoS mitigation is easier with a complete picture Bouncer designed to make it easier to detect and defend DoS—not a complete cure Security Response in the Age of Mass Customized Attacks Peleus Uhley and Karthik Raman Peleus Uhley and Karthik Raman, Adobe ASSET, blogs.adobe.com/asset/ Peleus and Karthik talked about response to mass-customized exploits. Attackers behave much like a business. "Mass customization" refers to concept discussed in the book Future Perfect by Stan Davis of Harvard Business School. Mass customization is differentiating a product for an individual customer, but at a mass production price. For example, the same individual with a debit card receives basically the same customized ATM experience around the world. Or designing your own PC from commodity parts. Exploit kits are another example of mass customization. The kits support multiple browsers and plugins, allows new modules. Exploit kits are cheap and customizable. Organized gangs use exploit kits. A group at Berkeley looked at 77,000 malicious websites (Grier et al., "Manufacturing Compromise: The Emergence of Exploit-as-a-Service", 2012). They found 10,000 distinct binaries among them, but derived from only a dozen or so exploit kits. Characteristics of Mass Malware: potent, resilient, relatively low cost Technical characteristics: multiple OS, multipe payloads, multiple scenarios, multiple languages, obfuscation Response time for 0-day exploits has gone down from ~40 days 5 years ago to about ~10 days now. So the drive with malware is towards mass customized exploits, to avoid detection There's plenty of evicence that exploit development has Project Manager bureaucracy. They infer from the malware edicts to: support all versions of reader support all versions of windows support all versions of flash support all browsers write large complex, difficult to main code (8750 lines of JavaScript for example Exploits have "loose coupling" of multipe versions of software (adobe), OS, and browser. This allows specific attacks against specific versions of multiple pieces of software. Also allows exploits of more obscure software/OS/browsers and obscure versions. Gave examples of exploits that exploited 2, 3, 6, or 14 separate bugs. However, these complete exploits are more likely to be buggy or fragile in themselves and easier to defeat. Future research includes normalizing malware and Javascript. Conclusion: The coming trend is that mass-malware with mass zero-day attacks will result in mass customization of attacks. x86 Rewriting: Defeating RoP and other Shinanighans Richard Wartell Richard Wartell The attack vector we are addressing here is: First some malware causes a buffer overflow. The malware has no program access, but input access and buffer overflow code onto stack Later the stack became non-executable. The workaround malware used was to write a bogus return address to the stack jumping to malware Later came ASLR (Address Space Layout Randomization) to randomize memory layout and make addresses non-deterministic. The workaround malware used was to jump t existing code segments in the program that can be used in bad ways "RoP" is Return-oriented Programming attacks. RoP attacks use your own code and write return address on stack to (existing) expoitable code found in program ("gadgets"). Pinkie Pie was paid $60K last year for a RoP attack. One solution is using anti-RoP compilers that compile source code with NO return instructions. ASLR does not randomize address space, just "gadgets". IPR/ILR ("Instruction Location Randomization") randomizes each instruction with a virtual machine. Richard's goal was to randomize a binary with no source code access. He created "STIR" (Self-Transofrming Instruction Relocation). STIR disassembles binary and operates on "basic blocks" of code. The STIR disassembler is conservative in what to disassemble. Each basic block is moved to a random location in memory. Next, STIR writes new code sections with copies of "basic blocks" of code in randomized locations. The old code is copied and rewritten with jumps to new code. the original code sections in the file is marked non-executible. STIR has better entropy than ASLR in location of code. Makes brute force attacks much harder. STIR runs on MS Windows (PEM) and Linux (ELF). It eliminated 99.96% or more "gadgets" (i.e., moved the address). Overhead usually 5-10% on MS Windows, about 1.5-4% on Linux (but some code actually runs faster!). The unique thing about STIR is it requires no source access and the modified binary fully works! Current work is to rewrite code to enforce security policies. For example, don't create a *.{exe,msi,bat} file. Or don't connect to the network after reading from the disk. Clowntown Express: interesting bugs and running a bug bounty program Collin Greene Collin Greene, Facebook Collin talked about Facebook's bug bounty program. Background at FB: FB has good security frameworks, such as security teams, external audits, and cc'ing on diffs. But there's lots of "deep, dark, forgotten" parts of legacy FB code. Collin gave several examples of bountied bugs. Some bounty submissions were on software purchased from a third-party (but bounty claimers don't know and don't care). We use security questions, as does everyone else, but they are basically insecure (often easily discoverable). Collin didn't expect many bugs from the bounty program, but they ended getting 20+ good bugs in first 24 hours and good submissions continue to come in. Bug bounties bring people in with different perspectives, and are paid only for success. Bug bounty is a better use of a fixed amount of time and money versus just code review or static code analysis. The Bounty program started July 2011 and paid out $1.5 million to date. 14% of the submissions have been high priority problems that needed to be fixed immediately. The best bugs come from a small % of submitters (as with everything else)—the top paid submitters are paid 6 figures a year. Spammers like to backstab competitors. The youngest sumitter was 13. Some submitters have been hired. Bug bounties also allows to see bugs that were missed by tools or reviews, allowing improvement in the process. Bug bounties might not work for traditional software companies where the product has release cycle or is not on Internet. Active Fingerprinting of Encrypted VPNs Anna Shubina Anna Shubina, Dartmouth Institute for Security, Technology, and Society (I missed the start of her talk because another track went overtime. But I have the DVD of the talk, so I'll expand later) IPsec leaves fingerprints. Using netcat, one can easily visually distinguish various crypto chaining modes just from packet timing on a chart (example, DES-CBC versus AES-CBC) One can tell a lot about VPNs just from ping roundtrips (such as what router is used) Delayed packets are not informative about a network, especially if far away from the network More needed to explore about how TCP works in real life with respect to timing Making Attacks Go Backwards Fuzzynop FuzzyNop, Mandiant This talk is not about threat attribution (finding who), product solutions, politics, or sales pitches. But who are making these malware threats? It's not a single person or group—they have diverse skill levels. There's a lot of fat-fingered fumblers out there. Always look for low-hanging fruit first: "hiding" malware in the temp, recycle, or root directories creation of unnamed scheduled tasks obvious names of files and syscalls ("ClearEventLog") uncleared event logs. Clearing event log in itself, and time of clearing, is a red flag and good first clue to look for on a suspect system Reverse engineering is hard. Disassembler use takes practice and skill. A popular tool is IDA Pro, but it takes multiple interactive iterations to get a clean disassembly. Key loggers are used a lot in targeted attacks. They are typically custom code or built in a backdoor. A big tip-off is that non-printable characters need to be printed out (such as "[Ctrl]" "[RightShift]") or time stamp printf strings. Look for these in files. Presence is not proof they are used. Absence is not proof they are not used. Java exploits. Can parse jar file with idxparser.py and decomile Java file. Java typially used to target tech companies. Backdoors are the main persistence mechanism (provided externally) for malware. Also malware typically needs command and control. Application of Artificial Intelligence in Ad-Hoc Static Code Analysis John Ashaman John Ashaman, Security Innovation Initially John tried to analyze open source files with open source static analysis tools, but these showed thousands of false positives. Also tried using grep, but tis fails to find anything even mildly complex. So next John decided to write his own tool. His approach was to first generate a call graph then analyze the graph. However, the problem is that making a call graph is really hard. For example, one problem is "evil" coding techniques, such as passing function pointer. First the tool generated an Abstract Syntax Tree (AST) with the nodes created from method declarations and edges created from method use. Then the tool generated a control flow graph with the goal to find a path through the AST (a maze) from source to sink. The algorithm is to look at adjacent nodes to see if any are "scary" (a vulnerability), using heuristics for search order. The tool, called "Scat" (Static Code Analysis Tool), currently looks for C# vulnerabilities and some simple PHP. Later, he plans to add more PHP, then JSP and Java. For more information see his posts in Security Innovation blog and NRefactory on GitHub. Mask Your Checksums—The Gorry Details Eric (XlogicX) Davisson Eric (XlogicX) Davisson Sometimes in emailing or posting TCP/IP packets to analyze problems, you may want to mask the IP address. But to do this correctly, you need to mask the checksum too, or you'll leak information about the IP. Problem reports found in stackoverflow.com, sans.org, and pastebin.org are usually not masked, but a few companies do care. If only the IP is masked, the IP may be guessed from checksum (that is, it leaks data). Other parts of packet may leak more data about the IP. TCP and IP checksums both refer to the same data, so can get more bits of information out of using both checksums than just using one checksum. Also, one can usually determine the OS from the TTL field and ports in a packet header. If we get hundreds of possible results (16x each masked nibble that is unknown), one can do other things to narrow the results, such as look at packet contents for domain or geo information. With hundreds of results, can import as CSV format into a spreadsheet. Can corelate with geo data and see where each possibility is located. Eric then demoed a real email report with a masked IP packet attached. Was able to find the exact IP address, given the geo and university of the sender. Point is if you're going to mask a packet, do it right. Eric wouldn't usually bother, but do it correctly if at all, to not create a false impression of security. Adventures with weird machines thirty years after "Reflections on Trusting Trust" Sergey Bratus Sergey Bratus, Dartmouth College (and Julian Bangert and Rebecca Shapiro, not present) "Reflections on Trusting Trust" refers to Ken Thompson's classic 1984 paper. "You can't trust code that you did not totally create yourself." There's invisible links in the chain-of-trust, such as "well-installed microcode bugs" or in the compiler, and other planted bugs. Thompson showed how a compiler can introduce and propagate bugs in unmodified source. But suppose if there's no bugs and you trust the author, can you trust the code? Hell No! There's too many factors—it's Babylonian in nature. Why not? Well, Input is not well-defined/recognized (code's assumptions about "checked" input will be violated (bug/vunerabiliy). For example, HTML is recursive, but Regex checking is not recursive. Input well-formed but so complex there's no telling what it does For example, ELF file parsing is complex and has multiple ways of parsing. Input is seen differently by different pieces of program or toolchain Any Input is a program input executes on input handlers (drives state changes & transitions) only a well-defined execution model can be trusted (regex/DFA, PDA, CFG) Input handler either is a "recognizer" for the inputs as a well-defined language (see langsec.org) or it's a "virtual machine" for inputs to drive into pwn-age ELF ABI (UNIX/Linux executible file format) case study. Problems can arise from these steps (without planting bugs): compiler linker loader ld.so/rtld relocator DWARF (debugger info) exceptions The problem is you can't really automatically analyze code (it's the "halting problem" and undecidable). Only solution is to freeze code and sign it. But you can't freeze everything! Can't freeze ASLR or loading—must have tables and metadata. Any sufficiently complex input data is the same as VM byte code Example, ELF relocation entries + dynamic symbols == a Turing Complete Machine (TM). @bxsays created a Turing machine in Linux from relocation data (not code) in an ELF file. For more information, see Rebecca "bx" Shapiro's presentation from last year's Toorcon, "Programming Weird Machines with ELF Metadata" @bxsays did same thing with Mach-O bytecode Or a DWARF exception handling data .eh_frame + glibc == Turning Machine X86 MMU (IDT, GDT, TSS): used address translation to create a Turning Machine. Page handler reads and writes (on page fault) memory. Uses a page table, which can be used as Turning Machine byte code. Example on Github using this TM that will fly a glider across the screen Next Sergey talked about "Parser Differentials". That having one input format, but two parsers, will create confusion and opportunity for exploitation. For example, CSRs are parsed during creation by cert requestor and again by another parser at the CA. Another example is ELF—several parsers in OS tool chain, which are all different. Can have two different Program Headers (PHDRs) because ld.so parses multiple PHDRs. The second PHDR can completely transform the executable. This is described in paper in the first issue of International Journal of PoC. Conclusions trusting computers not only about bugs! Bugs are part of a problem, but no by far all of it complex data formats means bugs no "chain of trust" in Babylon! (that is, with parser differentials) we need to squeeze complexity out of data until data stops being "code equivalent" Further information See and langsec.org. USENIX WOOT 2013 (Workshop on Offensive Technologies) for "weird machines" papers and videos.

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  • C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

    - by James Michael Hare
    Once again we consider some of the lesser known classes and keywords of C#.  In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>.  Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>.  Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework.  And out of this framework emerged the System.Collections namespace, and it was good.  It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections.  The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever!  With generics the C# language finally got an equivalent of the very powerful C++ templates.  As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections.  The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on.  The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well.  So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them.  The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required.  Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11:  12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20:  21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner.  Looking at  today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes.  With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe.  This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations.  Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5:  6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9:  10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17:  18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock.  With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level).  So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently!  For example, what if you have a Dictionary that has frequent reads but in-frequent updates?  Do you want to lock down the entire Dictionary for every access?  This would be overkill and would prevent concurrent reads.  In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell).  This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in.  The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null.  Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to.  Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic.  For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty!  This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models.  I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts.  Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration).  Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container.  If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations.  This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek().  This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed.  Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items.  Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6:  7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10:  11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call.  That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call.  This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: var results = stack.GetEnumerator(); 7:  8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10:  11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct.  You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all.  In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class.  The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays.  Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart.  Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count.  This results overall in a O(1) complexity which is quite good.  It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue.  There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue().  Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results.  Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5:  6: var iterator = queue.GetEnumerator(); 7:  8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10:  11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious.  Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation.  This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5:  6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12:  13: results.Enqueue(result); 14: }); 15:  16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here.   Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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  • Agile isn’t always Agile

    - by BuckWoody
    I want to make a disclaimer before I dive into this topic – At Microsoft we use all kinds of development methodologies, and I’ve worked in lots of other shops using lots of methodologies. This is one of those “religious” topics like which programming language or database is best, and is bound to generate some heat. But this isn’t pointed towards one particular event or company. But I really don’t like Agile. In particular, I really don’t like Scrum. Let me explain. Agile is a methodology for developing software that emphasizes adapting to change more so than the traditional “waterfall” method of developing software. Within Agile is a process called a “scrum” meeting. The pitch goes that in this quick, stand-up meeting the people involved in the development project (which should include the DBA, but very often doesn’t) go around the room stating what they are working on, when that will be finished and what is keeping them from getting finished (“blockers”, these are called). Sounds all very non-threatening – we’re just “enabling” the developers to work more efficiently. And that’s what we all want, isn’t it? Except it doesn’t work. In my experience (and yours might be VERY different) this just turns into a micro-management environment, where devs have to defend their daily work. Of all the work environments I hate the most, micro-management environments are THE worst. I don’t like workign in them, and I don’t like creating them. The other issue I have with Scrum is that it makes your whole team task-focused. Everyone wants to make sure that they are not the “long pole” in the meeting (meaning that they aren’t the one that gets all the attention) so they only focus on safe, quick tasks. And although you have all of the boxes checked, the project does not go well at all – even when it does finish. Before you comment (and please do comment) I fully realize that Agile <> Scrum. But in my experience, it sometimes turns into that. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Silverlight Cream for April 03, 2010 -- #829

    - by Dave Campbell
    In this Issue: Scott Marlowe, Nokola, SilverLaw, Brad Abrams, Jeff Wilcox, Jesse Liberty, Alexey Zakharov, ondrejsv, Ward Bell, and David Anson. Shoutouts: Bart Czernicki has a post up about the latest with HTML5: HTML 5 is Born Old - Quake in HTML 5 I was sent a link to shoebox360 a while back and had to sign up to see the Silverlight use, but it does work very nice. I like the panoramic carousel in the viewer: shoebox360 Jeff Handley has a post up on RIA Services - Documentation Guidance and Community Samples... the team is looking for feedback from all of us Shawn Wildermuth posted his My MIX Talks' Source Code Laurent Bugnion posted his Sample code and slides for my TechDays10 (Belgium) talks From SilverlightCream.com: Silverlight to WCF Cross Domain SecurityException Scott Marlowe wrote an article about an often-encountered security exception having to do with cross-domain policies. He details the problem, the response, the solution, and yet another problem/solution associated... good stuff, Scott! Simple Functions for HTML Interop You've seen Nokola's graphic work... how about some HTML Interop from him? He's exposing the code he uses in his work. New Video: ChildWindow Styling - Silverlight 3 SilverLaw has a new video tutorial on Silerlight 3 ChildWindow Styling up - in German - but the video is language-agnostic :) Silverlight 4 + RIA Services - Ready for Business: Exposing WCF (SOAP\WSDL) Services Brad Abrams' continuation in his RIA series is this one demonstrating exposing RIA Services as a Soap\WSDL service Silverlight 4: New parser implementation. New parser features. Jeff Wilcox has a post up highlighting some of the new features in Silverlight 4 such as a new parser implementation with new XAML features. New Video Series – Getting Started With Silverlight Jesse Liberty is starting a new video tutorial series that's going to build out to be a "complete survey of Silverlight programming". The first two are in this post and are Getting Started and Adding Controls to a Silverlight App... looks like good material, Jesse, and all the source is there for the taking as well. Silverlight layout hack: Centered content with fixed maxwidth Alexey Zakharov has a quick tip up on creating centered content with fixed maxwidth. He calls it a dirty trick... looks like code to me :) Silverlight DataForm’s autogenerated fields send empty strings to database ondrejsv points up a problem he had with the Toolkit's DataForm, and his solution to it... with code for all of us following along behind :) DevForce Extensibility With MEF InheritedExport Ward Bell has a post up describing how they got DevForce MEF'd up, and looks like a good post to get you all excited about MEF as well... lots of external links and good info. Tip: Read-only custom DependencyProperties don't exist in Silverlight, but can be closely approximated David Anson's latest Tip is about Read-only custom DependencyProperties in Silverlight -- which strictly is not possible, but he has a code example up that gets close. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • CRMIT Solution´s CRM++ Asterisk Telephony Connector Achieves Oracle Validated Integration with Oracle Sales Cloud

    - by Richard Lefebvre
    To achieve Oracle Validated Integration, Oracle partners are required to meet a stringent set of requirements that are based on the needs and priorities of the customers. Based on a Telephony Application Programming Interface (TAPI) framework the CRM++ Asterisk Telephony Connector integrates the Asterisk telephony solutions with Oracle® Sales Cloud. "The CRM++ Asterisk Telephony Connector for Oracle® Sales Cloud showcases CRMIT Solutions focus and commitment to extend the Customer Experience (CX) expertise to our existing and potential customers," said Vinod Reddy, Founder & CEO, CRMIT Solutions. "Oracle® Validated Integration applies a rigorous technical review and test process," said Kevin O’Brien, senior director, ISV and SaaS Strategy, Oracle®. "Achieving Oracle® Validated Integration through Oracle® PartnerNetwork gives our customers confidence that the CRM++ Asterisk Telephony Connector for Oracle® Sales Cloud has been validated and that the products work together as designed. This helps reduce deployment risk and improves the user experience for our joint customers." CRM++ is a suite of native Customer Experience solutions for Oracle® CRM On Demand, Oracle® Sales Cloud and Oracle® RightNow Cloud Service. With over 3000+ users the CRM++ framework helps extend the Customer Experience (CX) and the power of Customer Relations Management features including Email WorkBench, Self Service Portal, Mobile CRM, Social CRM and Computer Telephony Integration.. About CRMIT Solutions CRMIT Solutions is a pioneer in delivering SaaS-based customer experience (CX) consulting and solutions. With more than 200 certified customer relationship management (CRM) consultants and more than 175 successful CRM deployments globally, CRMIT Solutions offers a range of CRM++ applications for accelerated deployments including various rapid implementation and migration utilities for Oracle® Sales Cloud, Oracle® CRM On Demand, Oracle® Eloqua, Oracle® Social Relationship Management and Oracle® RightNow Cloud Service. About Oracle Validated Integration Oracle Validated Integration, available through the Oracle PartnerNetwork (OPN), gives customers confidence that the integration of complementary partner software products with Oracle Applications and specific Oracle Fusion Middleware solutions have been validated, and the products work together as designed. This can help customers reduce risk, improve system implementation cycles, and provide for smoother upgrades and simpler maintenance. Oracle Validated Integration applies a rigorous technical process to review partner integrations. Partners who have successfully completed the program are authorized to use the “Oracle Validated Integration” logo. For more information, please visit Oracle.com at http://www.oracle.com/us/partnerships/solutions/index.html.

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  • SQL SERVER – Automated Type Conversion using Expressor Studio

    - by pinaldave
    Recently I had an interesting situation during my consultation project. Let me share to you how I solved the problem using Expressor Studio. Consider a situation in which you need to read a field, such as customer_identifier, from a text file and pass that field into a database table. In the source file’s metadata structure, customer_identifier is described as a string; however, in the target database table, customer_identifier is described as an integer. Legitimately, all the source values for customer_identifier are valid numbers, such as “109380”. To implement this in an ETL application, you probably would have hard-coded a type conversion function call, such as: output.customer_identifier=stringToInteger(input.customer_identifier) That wasn’t so bad, was it? For this instance, programming this hard-coded type conversion function call was relatively easy. However, hard-coding, whether type conversion code or other business rule code, almost always means that the application containing hard-coded fields, function calls, and values is: a) specific to an instance of use; b) is difficult to adapt to new situations; and c) doesn’t contain many reusable sub-parts. Therefore, in the long run, applications with hard-coded type conversion function calls don’t scale well. In addition, they increase the overall level of effort and degree of difficulty to write and maintain the ETL applications. To get around the trappings of hard-coding type conversion function calls, developers need an access to smarter typing systems. Expressor Studio product offers this feature exactly, by providing developers with a type conversion automation engine based on type abstraction. The theory behind the engine is quite simple. A user specifies abstract data fields in the engine, and then writes applications against the abstractions (whereas in most ETL software, developers develop applications against the physical model). When a Studio-built application is run, Studio’s engine automatically converts the source type to the abstracted data field’s type and converts the abstracted data field’s type to the target type. The engine can do this because it has a couple of built-in rules for type conversions. So, using the example above, a developer could specify customer_identifier as an abstract data field with a type of integer when using Expressor Studio. Upon reading the string value from the text file, Studio’s type conversion engine automatically converts the source field from the type specified in the source’s metadata structure to the abstract field’s type. At the time of writing the data value to the target database, the engine doesn’t have any work to do because the abstract data type and the target data type are just the same. Had they been different, the engine would have automatically provided the conversion. ?Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Database, Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: SSIS

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  • What is Inversion of control and why we need it?

    - by Jalpesh P. Vadgama
    Most of programmer need inversion of control pattern in today’s complex real time application world. So I have decided to write a blog post about it. This blog post will explain what is Inversion of control and why we need it. We are going to take a real world example so it would be better to understand. The problem- Why we need inversion of control? Before giving definition of Inversion of control let’s take a simple real word example to see why we need inversion of control. Please have look on the following code. public class class1 { private class2 _class2; public class1() { _class2=new class2(); } } public class class2 { //Some implementation of class2 } I have two classes “Class1” and “Class2”.  If you see the code in that I have created a instance of class2 class in the class1 class constructor. So the “class1” class is dependent on “class2”. I think that is the biggest issue in real world scenario as if we change the “class2” class then we might need to change the “class1” class also. Here there is one type of dependency between this two classes that is called Tight Coupling. Tight coupling will have lots of problem in real world applications as things are tends to be change in future so we have to change all the tight couple classes that are dependent of each other. To avoid this kind of issue we need Inversion of control. What is Inversion of Control? According to the wikipedia following is a definition of Inversion of control. “In software engineering, Inversion of Control (IoC) is an object-oriented programming practice where the object coupling is bound at run time by an assembler object and is typically not known at compile time using static analysis.” So if you read the it carefully it says that we should have object coupling at run time not compile time where it know what object it will create, what method it will call or what feature it will going to use for that. We need to use same classes in such way so that it will not tight couple with each other. There are multiple way to implement Inversion of control. You can refer wikipedia link for knowing multiple ways of implementing Inversion of control. In future posts we are going to see all the different way of implementing Inversion of control.

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  • SQLAuthority News – Book Review – Beginning T-SQL 2008 by Kathi Kellenberger

    - by pinaldave
    Beginning T-SQL 2008 by Kathi Kellenberger Amazon Link Detail Review: Beginning T-SQL 2008 is one of the best books on the market if you are just beginning to work with Microsoft SQL, or have a little bit of experience and need to learn more quickly. Each chapter of the book introduces a new subject, and builds upon topics covered in previous chapters.  The author of the book, Kathi Kellenberger understands that you need to form a solid foundation of knowledge before moving on to new topics, and sets up each subject nicely.  Because the chapters move in an orderly progression, you continue to use skills you learned earlier. One of the best features of Beginning T-SQL 2008 is that each chapter has multiple examples and exercises.  Many books introduce a topic and then never go back to it.  This book gives enough examples that you will be familiar with the subject when you come across it in real life.  The exercises at the end of the chapter mean that you will be using the skills you learned – and there is no better way to cement a subject in your brain. The book also includes discussions of the common errors that programmers will come across, how to avoid them, and how to fix them if they happen.  Ms. Kellenberger understands that not only do mistakes happen, but they are bound to happen if you aren’t trained properly.  Mistakes are part of the learning process! The book begins by discussions relational theory, so that programmers will understand the way T-SQL works from the ground up.  It also walks readers through writing accurate queries, combining set-based and procedural processing, embedding logic in stored functions, and so much more. Overall, the main goal of Beginning T-SQL 2008 is to introduce novices to SQL programming, and quickly familiarize them with the basics of running the program.  The book is written with the idea that readers will not know any of the technical terms or vocabulary.  However, if you are a little more familiar with SQL and looking to become better, you will still find this book very helpful. Ratting: 4.5+ Stars Summary: I must recommend Beginning T-SQL 2008 highly enough.  If you are going to buy any beginners guide to Transect-SQL, this is the one you should spend your money on.  You can save yourself a lot of time and effort later by using this very affordable manual to learn the basics, which will allow you to become an expert much faster. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Book Review, SQLAuthority News, T SQL, Technology

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  • Microsoft, jQuery, and Templating

    - by Stephen Walther
    About two months ago, John Resig and I met at Café Algiers in Harvard square to discuss how Microsoft can contribute to the jQuery project. Today, Scott Guthrie announced in his second-day MIX keynote that Microsoft is throwing its weight behind jQuery and making it the primary way to develop client-side Ajax applications using Microsoft technologies. What does this announcement mean? It means that Microsoft is shifting its resources to invest in jQuery. Developers on the ASP.NET team are now working full-time to contribute features to the core jQuery library. Furthermore, we are working with other teams at Microsoft to ensure that our technologies work great with jQuery. We are contributing to the open-source jQuery project in the exact same way that any other company or individual from the community can contribute to jQuery. We are writing proposals, submitting the proposals to the jQuery forums, and revising the proposals in response to community feedback. The jQuery team can decide to reject or accept any feature that we propose. Any feature that Microsoft contributes to jQuery will be platform neutral. In other words, Microsoft contributions will benefit PHP and RAILS developers just as much as they benefit ASP.NET developers. Microsoft contributions to jQuery will improve the web for everyone. Contributing Support for Templates to jQuery Core Our first proposal concerns templating. We want to contribute support for templates to jQuery so that JavaScript developers can use jQuery to easily display a set of database records. You can read our templating proposal here: http://wiki.github.com/nje/jquery/jquery-templates-proposal You can download and play with our prototype for templating here: http://github.com/nje/jquery-tmpl The following code illustrates how you can use a template to display a set of products in a bulleted list: <script type="text/javascript"> jQuery(function(){ var products = [ { name: "Product 1", price: 12.99}, { name: "Product 2", price: 9.99}, { name: "Product 3", price: 35.59} ]; $("ul").append("#template", products); }); </script> <script id="template" type="text/html"> <li>{%= name %} - {%= price %}</li> </script> <ul></ul> The template is contained in a SCRIPT element that has a TYPE=”text/html” attribute. Browsers ignore the contents of a SCRIPT element when they don’t understand the content type. Notice that the placeholder {%=...%} is used within the template to indicate where the name and price of a product should appear. The delimiters {%=…%} are used for expressions and the delimiters {%...%} are used for code. Finally, the products are rendered using the template with the call to $(“ul”).append(“#template”, products). The standard jQuery DOM manipulation methods have been modified to support templates. When the page above is rendered, you get the bulleted list displayed in the following figure. Our goal is to keep our proposal for templates as simple as possible. After support for templating has been added to jQuery, plug-in authors can take advantage of templating when building complex data-driven plug-ins such as a DataGrid plug-in. The Ajax Control Toolkit Over 100,000 developers download the Ajax Control Toolkit every month. That’s a mind-boggling number of downloads. We realize that the Ajax Control Toolkit is extremely popular among ASP.NET Web Forms developers and we want to continue to invest in the Ajax Control Toolkit. If you are adding JavaScript interactivity to an ASP.NET Web Forms application, and you don’t want to write JavaScript, then we recommend that you use the server controls in the Ajax Control Toolkit. Using the Ajax Control Toolkit does not require knowledge of JavaScript and the toolkit enables you to build applications with the concepts familiar to ASP.NET Web Forms applications developers. If, however, you are interested in creating client-side interactivity without server controls then we recommend that you use jQuery. We plan to continue to release new versions of the Ajax Control Toolkit every few months. Our goal is to continue to improve the quality of the Ajax Control Toolkit and to make it easier for the community to contribute code, bug fixes, and documentation. The ASP.NET Ajax Library We are moving the ASP.NET Ajax Library into the Ajax Control Toolkit. If you currently use ASP.NET Ajax Library client templates, client data-binding, or the client script loader then you can continue to use these features by downloading the Ajax Control Toolkit. Be aware that our focus with the Ajax Control Toolkit is server-side Ajax.  For client-side Ajax, we are shifting our focus to jQuery. For example, if you have been using ASP.NET Ajax Library client templates then we recommend that you shift to using jQuery instead. Conclusion Our plan is to focus on jQuery as the primary technology for building client-side Ajax applications moving forward. We want to adapt Microsoft technologies to work great with jQuery and we want to contribute features to jQuery that will make the web better for everyone. We are very excited to be working with the jQuery core team.

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  • Welcome to my geeks blog

    - by bconlon
    Hi and welcome! I'm Bazza and this is my geeks blog. I have 20 years Visual Studio mainly C++, MFC,  ATL and now, thankfully, C# and I am embarking on the new world (well new to me) of WPF, so I thought I would try and capture my successful...and not so successful...WPF experiences with the geek world. So where to start? WPF? What I know so far... From wiki..."Windows Presentation Foundation (or WPF) is a graphical subsystem for rendering user interfaces in Windows-based applications." Hmm, great but didn't MFC, ATL (my head hurt with that one), and .Net all have APIs to allow me to code against the Windows Graphical Device Interface (GDI)? "Rather than relying on the older GDI subsystem, WPF utilizes DirectX. WPF attempts to provide a consistent programming model for building applications and provides a separation between the user interface and the business logic." OK, different drawing code, same Windows and weren't we always taught to separate our UI, Business Layer and Data Access Layer? "WPF employs XAML, a derivative of XML, to define and link various UI elements. WPF applications can be deployed as standalone desktop programs, or hosted as an embedded object in a website." Cool, now we're getting somewhere. So when they say separation they really mean separation. The crux of this appears to be that you can have creative people writing the UI and making it attractive and intuitive to use, whist the geeks concentrate on writing the Business and Data Access stuff. XAML (eXtensible Application Markup Language) maps XML elements and attributes directly to Common Language Runtime (CLR) object instances, properties and events. True separation of the View and Model. WPF also provides logical separation of a control from its appearance. In a traditional Windows system, all Controls have a base class containing a Windows handle and each Control knows how to render itself. In WPF, the controls are more like those in a Web Browser using Cascading Style Sheet, they are not wrappers for standard Windows Controls. Instead, they have a default 'template' that defines a visual theme which can easily be replaced by a custom template. But it gets better. WPF concentrates heavily on Data Binding where the client can bind directly to data on the server. I think this concept was first introduced in 'Classic' Visual Basic, where you could bind a list directly to a data from an Access database, and you could do similar in ASP .Net. However, the WPF implementation is far superior than it's predecessors. There are also other technologies that I want to look at like LINQ and the Entity Framework, but that's all for now. #

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  • Big Data – Buzz Words: Importance of Relational Database in Big Data World – Day 9 of 21

    - by Pinal Dave
    In yesterday’s blog post we learned what is HDFS. In this article we will take a quick look at the importance of the Relational Database in Big Data world. A Big Question? Here are a few questions I often received since the beginning of the Big Data Series - Does the relational database have no space in the story of the Big Data? Does relational database is no longer relevant as Big Data is evolving? Is relational database not capable to handle Big Data? Is it true that one no longer has to learn about relational data if Big Data is the final destination? Well, every single time when I hear that one person wants to learn about Big Data and is no longer interested in learning about relational database, I find it as a bit far stretched. I am not here to give ambiguous answers of It Depends. I am personally very clear that one who is aspiring to become Big Data Scientist or Big Data Expert they should learn about relational database. NoSQL Movement The reason for the NoSQL Movement in recent time was because of the two important advantages of the NoSQL databases. Performance Flexible Schema In personal experience I have found that when I use NoSQL I have found both of the above listed advantages when I use NoSQL database. There are instances when I found relational database too much restrictive when my data is unstructured as well as they have in the datatype which my Relational Database does not support. It is the same case when I have found that NoSQL solution performing much better than relational databases. I must say that I am a big fan of NoSQL solutions in the recent times but I have also seen occasions and situations where relational database is still perfect fit even though the database is growing increasingly as well have all the symptoms of the big data. Situations in Relational Database Outperforms Adhoc reporting is the one of the most common scenarios where NoSQL is does not have optimal solution. For example reporting queries often needs to aggregate based on the columns which are not indexed as well are built while the report is running, in this kind of scenario NoSQL databases (document database stores, distributed key value stores) database often does not perform well. In the case of the ad-hoc reporting I have often found it is much easier to work with relational databases. SQL is the most popular computer language of all the time. I have been using it for almost over 10 years and I feel that I will be using it for a long time in future. There are plenty of the tools, connectors and awareness of the SQL language in the industry. Pretty much every programming language has a written drivers for the SQL language and most of the developers have learned this language during their school/college time. In many cases, writing query based on SQL is much easier than writing queries in NoSQL supported languages. I believe this is the current situation but in the future this situation can reverse when No SQL query languages are equally popular. ACID (Atomicity Consistency Isolation Durability) – Not all the NoSQL solutions offers ACID compliant language. There are always situations (for example banking transactions, eCommerce shopping carts etc.) where if there is no ACID the operations can be invalid as well database integrity can be at risk. Even though the data volume indeed qualify as a Big Data there are always operations in the application which absolutely needs ACID compliance matured language. The Mixed Bag I have often heard argument that all the big social media sites now a days have moved away from Relational Database. Actually this is not entirely true. While researching about Big Data and Relational Database, I have found that many of the popular social media sites uses Big Data solutions along with Relational Database. Many are using relational databases to deliver the results to end user on the run time and many still uses a relational database as their major backbone. Here are a few examples: Facebook uses MySQL to display the timeline. (Reference Link) Twitter uses MySQL. (Reference Link) Tumblr uses Sharded MySQL (Reference Link) Wikipedia uses MySQL for data storage. (Reference Link) There are many for prominent organizations which are running large scale applications uses relational database along with various Big Data frameworks to satisfy their various business needs. Summary I believe that RDBMS is like a vanilla ice cream. Everybody loves it and everybody has it. NoSQL and other solutions are like chocolate ice cream or custom ice cream – there is a huge base which loves them and wants them but not every ice cream maker can make it just right  for everyone’s taste. No matter how fancy an ice cream store is there is always plain vanilla ice cream available there. Just like the same, there are always cases and situations in the Big Data’s story where traditional relational database is the part of the whole story. In the real world scenarios there will be always the case when there will be need of the relational database concepts and its ideology. It is extremely important to accept relational database as one of the key components of the Big Data instead of treating it as a substandard technology. Ray of Hope – NewSQL In this module we discussed that there are places where we need ACID compliance from our Big Data application and NoSQL will not support that out of box. There is a new termed coined for the application/tool which supports most of the properties of the traditional RDBMS and supports Big Data infrastructure – NewSQL. Tomorrow In tomorrow’s blog post we will discuss about NewSQL. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • ODI 12c's Mapping Designer - Combining Flow Based and Expression Based Mapping

    - by Madhu Nair
    post by David Allan ODI is renowned for its declarative designer and minimal expression based paradigm. The new ODI 12c release has extended this even further to provide an extended declarative mapping designer. The ODI 12c mapper is a fusion of ODI's new declarative designer with the familiar flow based designer while retaining ODI’s key differentiators of: Minimal expression based definition, The ability to incrementally design an interface and to extract/load data from any combination of sources, and most importantly Backed by ODI’s extensible knowledge module framework. The declarative nature of the product has been extended to include an extensible library of common components that can be used to easily build simple to complex data integration solutions. Big usability improvements through consistent interactions of components and concepts all constructed around the familiar knowledge module framework provide the utmost flexibility. Here is a little taster: So what is a mapping? A mapping comprises of a logical design and at least one physical design, it may have many. A mapping can have many targets, of any technology and can be arbitrarily complex. You can build reusable mappings and use them in other mappings or other reusable mappings. In the example below all of the information from an Oracle bonus table and a bonus file are joined with an Oracle employees table before being written to a target. Some things that are cool include the one-click expression cross referencing so you can easily see what's used where within the design. The logical design in a mapping describes what you want to accomplish  (see the animated GIF here illustrating how the above mapping was designed) . The physical design lets you configure how it is to be accomplished. So you could have one logical design that is realized as an initial load in one physical design and as an incremental load in another. In the physical design below we can customize how the mapping is accomplished by picking Knowledge Modules, in ODI 12c you can pick multiple nodes (on logical or physical) and see common properties. This is useful as we can quickly compare property values across objects - below we can see knowledge modules settings on the access points between execution units side by side, in the example one table is retrieved via database links and the other is an external table. In the logical design I had selected an append mode for the integration type, so by default the IKM on the target will choose the most suitable/default IKM - which in this case is an in-built Oracle Insert IKM (see image below). This supports insert and select hints for the Oracle database (the ANSI SQL Insert IKM does not support these), so by default you will get direct path inserts with Oracle on this statement. In ODI 12c, the mapper is just that, a mapper. Design your mapping, write to multiple targets, the targets can be in the same data server, in different data servers or in totally different technologies - it does not matter. ODI 12c will derive and generate a plan that you can use or customize with knowledge modules. Some of the use cases which are greatly simplified include multiple heterogeneous targets, multi target inserts for Oracle and writing of XML. Let's switch it up now and look at a slightly different example to illustrate expression reuse. In ODI you can define reusable expressions using user functions. These can be reused across mappings and the implementations specialized per technology. So you can have common expressions across Oracle, SQL Server, Hive etc. shielding the design from the physical aspects of the generated language. Another way to reuse is within a mapping itself. In ODI 12c expressions can be defined and reused within a mapping. Rather than replicating the expression text in larger expressions you can decompose into smaller snippets, below you can see UNIT_TAX AMOUNT has been defined and is used in two downstream target columns - its used in the TOTAL_TAX_AMOUNT plus its used in the UNIT_TAX_AMOUNT (a recording of the calculation).  You can see the columns that the expressions depend on (upstream) and the columns the expression is used in (downstream) highlighted within the mapper. Also multi selecting attributes is a convenient way to see what's being used where, below I have selected the TOTAL_TAX_AMOUNT in the target datastore and the UNIT_TAX_AMOUNT in UNIT_CALC. You can now see many expressions at once now and understand much more at the once time without needlessly clicking around and memorizing information. Our mantra during development was to keep it simple and make the tool more powerful and do even more for the user. The development team was a fusion of many teams from Oracle Warehouse Builder, Sunopsis and BEA Aqualogic, debating and perfecting the mapper in ODI 12c. This was quite a project from supporting the capabilities of ODI in 11g to building the flow based mapping tool to support the future. I hope this was a useful insight, there is so much more to come on this topic, this is just a preview of much more that you will see of the mapper in ODI 12c.

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  • The right way to start out in game development/design [closed]

    - by Marco Sacristão
    Greetings everyone I'm a 19 year old student looking for some help in the field of game development. This question may or may not seem a bit overused, but the fact is that game development has been my life long dream, and after several hours of search I've realized that I've been going in circles for the past three or four months whilst doing such research on how to really get down and dirty with game development, therefor I decided to ask you guys if you could help me out at all. Let me start off with some information about me and things i've already learned about GameDev which might help you out on helping me out (wordplay!): I'm not an expert programmer, but I do have knowledge on how to program in several languages including C and Java (Currently learning Java in my degree in Computer Engineering), but my methodology might not be most correct in terms of syntax (hence my difficulty in starting out, i'm afraid that the starting point might not be the most correct, and it would deploy a wrongful development methodology that would be to corrected later on, in terms of game development or other projects). I have yet to work in a project as large as a game, never in my learning curve of programming I've done a project to the scale of a video game, only very small software (PHP Front-ends and Back-ends, with some basic JQuery and CSS knowledge). I'm not the biggest mathematician or physicist, but I already know that is not a problem, because there are several game engines already available for use and integration with home-made projects (Box2D, etc). I've also learned about some libraries that could be included in said projects, to ease out some process in game development, like SDL for example. I do not know how sprites, states, particles or any specific game-related techniques work. With that being said, you can see that I have some ideas on game development, but I have absolutely no clue on how to design and produce a game, or even how game-like mechanics work. It does not have to be a complex game just to start out, I'd rather learn the basic of game design (Like 2D drawing, tiling, object collision) and test that out in a language that I feel comfortable in which could be later on migrated to other platforms, as long that what I've learned is the correct way to do things, and not just something that I've learned from some guy on Youtube by replicating that code on the video. I'm sorry if my question is not in the best format possible, but I've got so many questions on my mind that are still un-answered that I don't know were to start! Thank you for reading.

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  • Craftsmanship Tour: Day 3 &amp; 4 8th Light

    - by Liam McLennan
    Thursday morning the Illinois public transport system came through for me again. I took the Metra train north from Union Station (which was seething with inbound commuters) to Prairie Crossing (Libertyville). At Prairie Crossing I met Paul and Justin from 8th Light and then Justin drove us to the office. The 8th Light office is in an small business park, in a semi-rural area, surrounded by ponds. Upstairs there are two spacious, open areas for developers. At one end of the floor is Doug Bradbury’s walk-and-code station; a treadmill with a desk and computer so that a developer can get exercise at work. At the other end of the floor is a hammock. This irregular office furniture is indicative of the 8th Light philosophy, to pursue excellence without being limited by conventional wisdom. 8th Light have a wall covered in posters, each illustrating one person’s software craftsmanship journey. The posters are a fascinating visualisation of the similarities and differences between each of our progressions. The first thing I did Thursday morning was to create my own poster and add it to the wall. Over two days at 8th Light I did some pairing with the 8th Lighters and we shared thoughts on software development. I am not accustomed to such a progressive and enlightened environment and I found the experience inspirational. At 8th Light TDD, clean code, pairing and kaizen are deeply ingrained in the culture. Friday, during lunch, 8th Light hosted a ‘lunch and learn’ event. Paul Pagel lead us through a coding exercise using micro-pomodori. We worked in pairs, focusing on the pedagogy of pair programming and TDD. After lunch I recorded this interview with Paul Pagel and Justin Martin. We discussed 8th light, craftsmanship, apprenticeships and the limelight framework. Interview with Paul Pagel and Justin Martin My time at Didit, Obtiva and 8th Light has convinced me that I need to give up some of my independence and go back to working in a team. Craftsmen advance their skills by learning from each other, and I can’t do that working at home by myself. The challenge is finding the right team, and becoming a part of it.

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  • SQLAuthority News – A Real Story of Book Getting ‘Out of Stock’ to A 25% Discount Story Available

    - by pinaldave
    As many of my readers may know, I have recently written a few books.  Right now I’d like to talk about SQL Server Interview Questions and Answers (http://bit.ly/sqlinterviewbook ), my newest release. What inspired me to write this book was similar to my motivations for my previous titles – I wanted to help people understand SQL Server concepts and ace interview questions so that they could get a great job they love, as much as I love my own job. If you are new to SQL Server, don’t think I left you out of my book writing efforts. If you are new to the subject or have not had to deal with SQL Server in a long time, this book is perfect for someone who wants or needs a last minute refresher. If you are facing an upcoming interview and want to impress your future bosses, this book is perfect for getting you up to speed in a short time. However, if you are already an expert, you will still find a lot to learn and many pointers and suggestions that go deep into the subject. As I said before, I wrote this book in order to help my community, and I certainly hoped that this book would become popular. However, we decided to print a very limited number of copies to begin with. We did not think that it would sell out since much of the information is available for free online. We could not have been more wrong! We incorrectly estimated what people wanted. We did not realize that there is still a need and an interest for structured learning. So, with great reservations, we printed quite a large number of copies – and it still ran out in 36 hours! We got call from the online store with a request for more copies within 12 hours. But we had printed only as many as we had sent them. There were no extra copies. We finally talked to the printer to get more copies. However, due to festivals and holidays the copies could not be shipped to the online retailer for two days. We knew for sure that they were going to be out of the book for 48 hours. 48 hours – this was very difficult as the book was very highly anticipated. Many people wanted to buy this book quickly, and receive it soon in order to meet a deadline or to study for an upcoming test of their knowledge. But now this book was out of stock on the retail store. The way the online store works is that if the Indian-priced book is not there they list the US version of the book so that buyers will not be disappointed. The problem was that the US price of the book is three times more than the Indian price – which means one has to pay three times as much to buy this book instead of the previous very low price. We received a lot of communication on this subject, here are some examples: We are now businessmen and only focusing on money Why has the price tripled in 36 hours Why we are not honest with the price If the prices will ever come down And some of the letters we cannot post here! Well, finally after 48 hours the Indian stock was finally available online. Thanks to our printer who worked day and night to get all the copies printed. He divided the complete stock in two parts. The first part they sent immediately to online retailer  and the second part they kept with them to sell. Finally, the online retailer got them online promptly as well, and the price returned to normal. Our book once again got in business and became the eighth most popular new release in 36 hours. We appreciate your love and support. Without all of your interest and love we would have never come this far and the book would not be so successful. After thinking about all your support and how patient you were with our online troubles, the online retailer has decided to give an extra 25% discount for a limited time only. I think the 48 hours when the book was out of stock were very horrible and stressful and I’d like to apologize to my loyal readers for the mishap. I hope that the 25% off is enough to sooth any remaining hurt feelings, and that everyone will continue to learn and discover things in the book. Once again thank you so much and I truly hope that you all enjoy reading the book as much as I enjoyed writing it. My book SQL Server Interview Questions and Answers is available now. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Pinal Dave, PostADay, SQL, SQL Authority, SQL Interview Questions and Answers, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Book Review, SQLAuthority News, T SQL, Technology

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  • Friday Fun: Factory Balls – Christmas Edition

    - by Asian Angel
    Your weekend is almost here, but until the work day is over we have another fun holiday game for you. This week your job is to correctly decorate/paint the ornaments that go on the Christmas tree. Simple you say? Maybe, but maybe not! Factory Balls – Christmas Edition The object of the game is to correctly decorate/paint each Christmas ornament exactly as shown in the “sample image” provided for each level. What starts off as simple will quickly have you working to figure out the correct combination or sequence to complete each ornament. Are you ready? The first level serves as a tutorial to help you become comfortable with how to decorate/paint the ornaments. To move an ornament to a paint bucket or cover part of it with one of the helper items simply drag the ornament towards that area. The ornament will automatically move back to its’ starting position when the action is complete. First, a nice coat of red paint followed by covering the middle area with a horizontal belt. Once the belt is on move the ornament to the bucket of yellow paint. Next, you will need to remove the belt, so move the ornament back to the belt’s original position. One ornament finished! As soon as you complete decorating/painting an ornament, you move on to the next level and will be shown the next “sample Image” in the upper right corner. Starting with a coat of orange paint sounds good… Pop the little serrated edge cap on top… Add some blue paint… Almost have it… Place the large serrated edge cap on top… Another dip in the orange paint… And the second ornament is finished. Level three looks a little bit tougher…just work out your pattern of helper items & colors and you will definitely get it! Have fun decorating/painting those ornaments! Note: Starting with level four you will need to start using a combination of two helper items combined at times to properly complete the ornaments. Play Factory Balls – Christmas Edition Latest Features How-To Geek ETC The Complete List of iPad Tips, Tricks, and Tutorials The 50 Best Registry Hacks that Make Windows Better The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor Exploring the Jungle Ruins Wallpaper Protect Your Privacy When Browsing with Chrome and Iron Browser Free Shipping Day is Friday, December 17, 2010 – National Free Shipping Day Find an Applicable Quote for Any Programming Situation Winter Theme for Windows 7 from Microsoft Score Free In-Flight Wi-Fi Courtesy of Google Chrome

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  • Formal Languages, Inductive Proofs &amp; Regular Expressions

    - by MarkPearl
    So I am slogging away at my UNISA stuff. I have just finished doing the initial once non stop read through the first 11 chapters of my COS 201 Textbook - “Introduction to Computer Theory 2nd Edition” by Daniel Cohen. It has been an interesting couple of days, with familiar concepts coming up as well as some new territory. In this posting I am going to cover the first couple of chapters of the book. Let start with Formal Languages… What exactly is a formal language? Pretty much a no duh question for me but still a good one to ask – a formal language is a language that is defined in a precise mathematical way. Does that mean that the English language is a formal language? I would say no – and my main motivation for this is that one can have an English sentence that is correct grammatically that is also ambiguous. For example the ambiguous sentence: "I once shot an elephant in my pyjamas.” For this and possibly many other reasons that I am unaware of, English is termed a “Natural Language”. So why the importance of formal languages in computer science? Again a no duh question in my mind… If we want computers to be effective and useful tools then we need them to be able to evaluate a series of commands in some form of language that when interpreted by the device no confusion will exist as to what we were requesting. Imagine the mayhem that would exist if a computer misinterpreted a command to print a document and instead decided to delete it. So what is a Formal Language made up of… For my study purposes a language is made up of a finite alphabet. For a formal language to exist there needs to be a specification on the language that will describe whether a string of characters has membership in the language or not. There are two basic ways to do this: By a “machine” that will recognize strings of the language (e.g. Finite Automata). By a rule that describes how strings of a language can be formed (e.g. Regular Expressions). When we use the phrase “string of characters”, we can also be referring to a “word”. What is an Inductive Proof? So I am not to far into my textbook and of course it starts referring to proofs and different types. I have had to go through several different approaches of proofs in the past, but I can never remember their formal names , so when I saw “inductive proof” I thought to myself – what the heck is that? Google to the rescue… An inductive proof is like a normal proof but it employs a neat trick which allows you to prove a statement about an arbitrary number n by first proving it is true when n is 1 and then assuming it is true for n=k and showing it is true for n=k+1. The idea is that if you want to show that someone can climb to the nth floor of a fire escape, you need only show that you can climb the ladder up to the fire escape (n=1) and then show that you know how to climb the stairs from any level of the fire escape (n=k) to the next level (n=k+1). Does this sound like a form of recursion? No surprise then that in the same chapter they deal with recursive definitions. An example of a recursive definition for the language EVEN would the 3 rules below: 2 is in EVEN If x is in EVEN then so is x+2 The only elements in the set EVEN are those that be produced by the rules above. Nothing to exciting… So if a definition for a language is done recursively, then it makes sense that the language can be proved using induction. Regular Expressions So I am wondering to myself what use is this all – in fact – I find this the biggest challenge to any university material is that it is quite hard to find the immediate practical applications of some theory in real life stuff. How great was my joy when I suddenly saw the word regular expression being introduced. I had been introduced to regular expressions on Stack Overflow where I was trying to recognize if some text measurement put in by a user was in a valid form or not. For instance, the imperial system of measurement where you have feet and inches can be represented in so many different ways. I had eventually turned to regular expressions as an easy way to check if my parser could correctly parse the text or not and convert it to a normalize measurement. So some rules about languages and regular expressions… Any finite language can be represented by at least one if not more regular expressions A regular expressions is almost a rule syntax for expressing how regular languages can be formed regular expressions are cool For a regular expression to be valid for a language it must be able to generate all the words in the language and no other words. This is important. It doesn’t help me if my regular expression parses 100% of my measurement texts but also lets one or two invalid texts to pass as well. Okay, so this posting jumps around a bit – but introduces some very basic fundamentals for the subject which will be built on in later postings… Time to go and do some practical examples now…

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  • Share OneNote 2010 Notebooks with OneNote 2007

    - by Matthew Guay
    OneNote is the new star of the Office Suite, and is included in every edition of Office 2010.  OneNote’s file format has been changed in the 2010 version, so here’s how you can still share your notebooks with those using OneNote 2007. Convert your OneNote Notebooks to 2007 Format If you open a notebook from OneNote 2010 in OneNote 2007, you may see this warning informing you that the notebook was created in a newer version of OneNote and cannot be opened. To make your 2010 notebooks compatible with OneNote 2007, you need to convert them inside OneNote 2010.  In OneNote 2010, open the File menu; this should open to the Info tab by default.  Select the Settings button beside the notebook you want to use in OneNote 2007, and select Properties. In the properties dialog, click “Convert to 2007”. You may see a warning that some formatting, content, and history that is incompatible with OneNote 2007 will be removed.  Click Ok to continue. OneNote will automatically convert everything in this notebook to 2007 format.  If your notebook is very large, this may take a few minutes. Once the conversion is completed, you can re-open the properties dialog to see the change.  The format is listed as OneNote 2007 format, and you have the option to convert to 2010.  Your 2007 formatted notebook is still fully usable in OneNote 2010, but you may not be able to use some of the newer features in it. Now that your notebook is in 2007 format, you can share it with OneNote 2007 users.  Here’s our notebook, the OneNote 2010 guide, open in OneNote 2007 after the conversion. Conclusion OneNote can be a great collaboration tool, and with this simple trick you can collaborate with those using older versions of OneNote.  Additionally, if you are currently running Office 2010 beta but plan to switch back to Office 2007 when the beta expires, then make sure to do this to any new notebooks you’ve created so you can still use them. Similar Articles Productive Geek Tips OCR anything with OneNote 2007 and 2010How To Upload Office 2010 Documents to Web Apps Technical PreviewShare Your Calendar in Outlook 2003 / Exchange EnvironmentSee Where a Package is Installed on UbuntuClear All Browsing History in Safari TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites Restore Hidden Updates in Windows 7 & Vista Iceland an Insurance Job?

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  • Java Spotlight Episode 139: Mark Heckler and José Pereda on JES based Energy Monitoring @MkHeck @JPeredaDnr

    - by Roger Brinkley
    Interview with Mark Heckler and José Pereda on using JavaSE Embedded with the Java Embedded Suite on a RaspberryPI along with a JavaFX client to monitor an energy production system and their JavaOne Tutorial- Java Embedded EXTREME MASHUPS: Building self-powering sensor nets for the IoT Right-click or Control-click to download this MP3 file. You can also subscribe to the Java Spotlight Podcast Feed to get the latest podcast automatically. If you use iTunes you can open iTunes and subscribe with this link: Java Spotlight Podcast in iTunes. Show Notes News Java Virtual Developer Day Session Videos Available JavaFX Maven Plugin 2.0 Released JavaFX Scene Builder 1.1 build b28 FXForm 2 release 0.2.2 OpenJDK8/Zero cross compile build for Foundation model HSAIL-based GPU offload: the Quest for Java Performance Begins Progress on Moving to Gradle Java EE 7 Launch Keynote Replay Java EE 7 Technical Breakouts Replay Java EE 7 support in NetBeans 7.3.1 Java EE 7 support in Eclipse 4.3 Java Magazine - May/June Events Jul 16-19, Uberconf, Denver, USA Jul 22-24, JavaOne Shanghai, China Jul 29-31, JVM Language Summit, Santa Clara Sep 11-12, JavaZone, Oslo, Norway Sep 19-20, Strange Loop, St. Louis Sep 22-26 JavaOne San Francisco 2013, USA Feature Interview Mark Heckler is an Oracle Corporation Java/Middleware/Core Tech Engineer with development experience in numerous environments. He has worked for and with key players in the manufacturing, emerging markets, retail, medical, telecom, and financial industries to develop and deliver critical capabilities on time and on budget. Currently, he works primarily with large government customers using Java throughout the stack and across the enterprise. He also participates in open-source development at every opportunity, being a JFXtras project committer and developer of DialogFX, MonologFX, and various other projects. When Mark isn't working with Java, he enjoys writing about his experiences at the Java Jungle website (https://blogs.oracle.com/javajungle/) and on Twitter (@MkHeck). José Pereda is a Structural Engineer working in the School of Engineers in the University of Valladolid in Spain for more than 15 years, and his passion is related to applying programming to solve real problems. Being involved with Java since 1999, José shares his time between JavaFX and the Embedded world, developing commercial applications and open source projects (https://github.com/jperedadnr), and blogging (http://jperedadnr.blogspot.com.es/) or tweeting (@JPeredaDnr) of both. What’s Cool AquaFX 0.1 - Mac OS X skin for JavaFX by Claudine Zillmann DromblerFX adds a docking framework Part 2 of Gerrit’s taming the Nashorn for writing JavaFX apps in Javascript Tool from mihosoft called JSelect for quickly switching JDKs Apache Maven Javadoc Plugin 2.9.1 Released Proposal: Java Concurrency Stress tests (jcstress) Slide-free Code-driven session at SV JUG JavaOne approvals/rejects gone out

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  • Quickly Preview Songs in Windows Media Center 12 in Windows 7

    - by DigitalGeekery
    Do you ever wish you could quickly preview a song without having to play it? Today we look at a quick and easy way to do that in Windows Media Player 12. Open Windows Media Player in Library Mode and select your Music library. Hover your cursor over the Title of the song and a Preview pop-up window will appear after a few seconds.    Click on the Preview in the pop-up window and the song will begin to play. As the preview begins to play, you will see the Skip link and a song timer. Click on Skip to jump ahead 15 seconds in the song. When you are finished previewing the song, simply move your mouse away from the preview window to stop playback. Automatically Preview Songs You can adjust settings in Windows Media Player to automatically preview songs when you hover your cursor over the title. Select Tools  from the menu and click Options. On the Options window, select the Library tab and click on Automatically preview songs on title hover. Click OK.   Now when you simply hover your cursor over the song title the preview window will appear and playback will begin automatically. This feature works just as well in Details view as it does in Expanded Tile view. Would you like to stream your music to other computers on your network? Check out our article on how to stream media to other Windows 7 computers. Similar Articles Productive Geek Tips Using Netflix Watchnow in Windows Vista Media Center (Gmedia)Add Color Coding to Windows 7 Media Center Program GuideSchedule Updates for Windows Media CenterIntegrate Hulu Desktop and Windows Media Center in Windows 7Integrate Boxee with Media Center in Windows 7 TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites

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