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  • What Precalculus knowledge is required before learning Discrete Math Computer Science topics?

    - by Ein Doofus
    Below I've listed the chapters from a Precalculus book as well as the author recommended Computer Science chapters from a Discrete Mathematics book. Although these chapters are from two specific books on these subjects I believe the topics are generally the same between any Precalc or Discrete Math book. What Precalculus topics should one know before starting these Discrete Math Computer Science topics?: Discrete Mathematics CS Chapters 1.1 Propositional Logic 1.2 Propositional Equivalences 1.3 Predicates and Quantifiers 1.4 Nested Quantifiers 1.5 Rules of Inference 1.6 Introduction to Proofs 1.7 Proof Methods and Strategy 2.1 Sets 2.2 Set Operations 2.3 Functions 2.4 Sequences and Summations 3.1 Algorithms 3.2 The Growths of Functions 3.3 Complexity of Algorithms 3.4 The Integers and Division 3.5 Primes and Greatest Common Divisors 3.6 Integers and Algorithms 3.8 Matrices 4.1 Mathematical Induction 4.2 Strong Induction and Well-Ordering 4.3 Recursive Definitions and Structural Induction 4.4 Recursive Algorithms 4.5 Program Correctness 5.1 The Basics of Counting 5.2 The Pigeonhole Principle 5.3 Permutations and Combinations 5.6 Generating Permutations and Combinations 6.1 An Introduction to Discrete Probability 6.4 Expected Value and Variance 7.1 Recurrence Relations 7.3 Divide-and-Conquer Algorithms and Recurrence Relations 7.5 Inclusion-Exclusion 8.1 Relations and Their Properties 8.2 n-ary Relations and Their Applications 8.3 Representing Relations 8.5 Equivalence Relations 9.1 Graphs and Graph Models 9.2 Graph Terminology and Special Types of Graphs 9.3 Representing Graphs and Graph Isomorphism 9.4 Connectivity 9.5 Euler and Hamilton Ptahs 10.1 Introduction to Trees 10.2 Application of Trees 10.3 Tree Traversal 11.1 Boolean Functions 11.2 Representing Boolean Functions 11.3 Logic Gates 11.4 Minimization of Circuits 12.1 Language and Grammars 12.2 Finite-State Machines with Output 12.3 Finite-State Machines with No Output 12.4 Language Recognition 12.5 Turing Machines Precalculus Chapters R.1 The Real-Number System R.2 Integer Exponents, Scientific Notation, and Order of Operations R.3 Addition, Subtraction, and Multiplication of Polynomials R.4 Factoring R.5 Rational Expressions R.6 Radical Notation and Rational Exponents R.7 The Basics of Equation Solving 1.1 Functions, Graphs, Graphers 1.2 Linear Functions, Slope, and Applications 1.3 Modeling: Data Analysis, Curve Fitting, and Linear Regression 1.4 More on Functions 1.5 Symmetry and Transformations 1.6 Variation and Applications 1.7 Distance, Midpoints, and Circles 2.1 Zeros of Linear Functions and Models 2.2 The Complex Numbers 2.3 Zeros of Quadratic Functions and Models 2.4 Analyzing Graphs of Quadratic Functions 2.5 Modeling: Data Analysis, Curve Fitting, and Quadratic Regression 2.6 Zeros and More Equation Solving 2.7 Solving Inequalities 3.1 Polynomial Functions and Modeling 3.2 Polynomial Division; The Remainder and Factor Theorems 3.3 Theorems about Zeros of Polynomial Functions 3.4 Rational Functions 3.5 Polynomial and Rational Inequalities 4.1 Composite and Inverse Functions 4.2 Exponential Functions and Graphs 4.3 Logarithmic Functions and Graphs 4.4 Properties of Logarithmic Functions 4.5 Solving Exponential and Logarithmic Equations 4.6 Applications and Models: Growth and Decay 5.1 Systems of Equations in Two Variables 5.2 System of Equations in Three Variables 5.3 Matrices and Systems of Equations 5.4 Matrix Operations 5.5 Inverses of Matrices 5.6 System of Inequalities and Linear Programming 5.7 Partial Fractions 6.1 The Parabola 6.2 The Circle and Ellipse 6.3 The Hyperbola 6.4 Nonlinear Systems of Equations

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  • 5 ways to stop code thrashing&hellip;

    - by MarkPearl
    A few days ago I was programming on a personal project and hit a roadblock. I was applying the MVVM pattern and for some reason my view model was not updating the view when the state changed??? I had applied this pattern many times before and had never had this problem. It just didn’t make sense. So what did I do… I did what anyone would have done in my situation and looked to pass the blame to someone or something else. I tried to blame one of the inherited base classes, but it looked fine, then to Visual Studio, but it seemed to be fine and eventually to any random segment of code I came across. My elementary problem had now mushroomed into one that had lost any logical basis and I was in thrashing mode! So what to do when you begin to thrash? 1) Do a general code cleanup – Now there is a difference between cleaning code and changing code . When you thrash you change code and you want to avoid this. What you really want to do is things like rename variables to have better meaning and go over your comments. 2) Do a proof of concept – if cleaning code doesn’t help. The  you want to isolate the problem and identify the key concepts. When you isolate code you ideally want it to be in a totally separate project with as little complexity as possible. Make the building blocks and try and replicate the functionality that you are getting in your current application. 3) Phone a friend – I have found speaking to someone else about the problem generally helps me solve any thrashing issues I am having. Usually they don’t even have to say anything to solve the problem, just you talking them through the problem helps you get clarity of mind. 4) Let the dust settle – Sometimes time is the best solution. I have had a few problems that no matter who I discussed them with and no matter how much code cleaning I had done I just couldn’t seem to fix it. My brain just seemed to be going in circles. A good nights rest has always helped and often just the break away from the problem has helped me find a solution. 5) Stack overflow it – So similar to phone a friend. I am really surprised to see what a melting pot stack overflow has been and what a help it has been in solving technology specific problems. Just be considerate to those using the site and explain clearly exactly what problem you are having and the technologies you are using or else you will probably not get any useful help…

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  • Paranoid management, contractor checking work [closed]

    - by user833345
    Just wanted to get some opinions and experiences on an issue I'm having at work. First, a little background. I've been working at a company for some time (past any probation periods) and rewriting a horrendous system. No tests, incomplete and broken functionality everywhere, enough copypasta to feed a small village, redundant code, more unused SQL tables than used ones and terrible performance. I've never seen such bad code, pretty much all of it is worthy of being posted on TheDailyWTF. The company has been operating for a number of years and have had a string of bad developers working on this system. I made a call on rewriting instead of refactoring since I judged it to be less work overall and decided that the result will address the requirements more appropriately, since the central requirement is to have a future-proof system for the next decade with plenty of room to scale up. Refactoring would have entailed untangling a huge ball of yarn and at the same time integrating it with a proper foundation or building a foundation from scratch. I've introduced the latest spiffy framework, unit & functional testing, CI, a bug tracker and agile workflow to the environment. I've fixed most of the performance issues of the old system (there were no indexes on any of the tables, for example). I've created an automated deployment process for the old system. The CTO has been maintaining the old system while I have been building the new one and he has been advising management that everything is being done as per best practices. However, management is hiring a contractor to come in and verify my work. In my experience, this is unprecedented. I can understand their reasoning to an extent, since they've had bad luck in the past, but can't help but feel somewhat offended at the fact that they distrust two senior developers who have been working with them for some time enough that a third party is being brought in. And it's not just me who is under watch - people's emails are constantly checked, someone had a remote desktop application installed on their computer of which I was asked to check the usage logs to try to determine if they were stealing sensitive data and there are CCTV cameras in one of the rooms. It's the first time I've decided to disable my Skype history at work. Am I right to feel indignant here? Has anyone else ever encountered such a situation? If so, how did it work out in the end? Was it worth sticking around? Should I just find another job?

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  • eSTEP Newsletter for October 2013 now available

    - by uwes
    Dear Partners,We would like to let you know that the October'13 issue of our Newsletter is now available.The issue contains information on the following topics: Oracle Open World Summary Oracle Cloud: Oracle Engineered Systems Oracle Database and Middleware Oracle Applications and Software as a Service Oracle Industries Oracle Partners and the "Internet of Things" JavaOne News MySQL News Corporate News Create Your HR Strategic Vision at Oracle HCM World Oracle Database Protection Redefined A Preview: Oracle Database Backup Logging Recovery Appliance Oracle closed Tekelec acquisition Congratulations to ORACLE TEAM USA! Tech sectionARC M6 Oracle's SPARC M6 Oracle SuperCluster M6-32 - Oracle’s Most Scalable Engineered System Oracle Multitenant on SPARC Servers and Oracle Solaris Oracle Database 12c Enterprise Edition: Plug into the Cloud Oracle In-Memory Database Cache Oracle Virtual Compute Appliance New Benchmark-Results published (Sept. 2013) Video Interview: Elasticity, the Biggest Challenge Facing Data Centers Today Tech blog Announcing New Sun Storage 2500-M2 Drives SPARC Product Line Update ZFS RAID Calculator v6 What ships with ODA X3-2? Tech Article: Oracle Multitenant on SPARC Servers and Oracle Solaris New release of Sun Rack II capacity calculator available Announcing: Oracle Solaris Cluster Product Bulletin, September 2013 Learning & events Planned TechCasts Quarterly Partner Update Live Webcast: Simplify and Accelerate Oracle Database deployment with Oracle VM Templates Join us for OTN's Virtual Developer Day - Harnessing the Power of Oracle WebLogic and Oracle Coherence.Learn from OOW 2013 what is going on in Virtualization How to Implementing Early Arriving Facts in ODI, Part I and Part II: Proof of Concept Overview Multi-Factor Authentication in Oracle WebLogic Using multi-factor authentication to protect web applications deployed on Oracle WebLogic. If Virtualization Is Free, It Can't Be Any Good—Right? Looking beyond System/HW SOA and User Interfaces Overcoming the challenges to developing user interfaces in a service oriented References Vodafone Romania Improves Business Agility and Customer Satisfaction, with 10x Faster Business Intelligence Delivery and 12x Faster Processing Emirates Integrated Telecommunications Captures 47% Market Share in a Competitive Market, Thanks to 24/7 Availability Home Credit and Finance Bank Accelerates Getting New Banking Products to Market Extra A Conversation with Java Champion Johan VosYou can find the Newsletter on our portal under eSTEP News ---> Latest Newsletter. You will need to provide your email address and the pin below to get access. Link to the portal is shown below.URL: http://launch.oracle.com/PIN: eSTEP_2011Previous published Newsletters can be found under the Archived Newsletters section and more useful information under the Events, Download and Links tab. Feel free to explore and any feedback is appreciated to help us improve the service and information we deliver.Thanks and best regards,Partner HW Enablement EMEA

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  • Goodbye, Spreadsheets and Hello Modern ERP

    - by Christine Randle
    By: Steve Cox, Vice President, Oracle Accelerate for Midsize Companies     Signs of the resurging economy continue to sprout, with green shoots rising across different sectors and industries. With the economy on the rebound, businesses are increasing their investment in technology to keep up with growth and evolving demands; as proof, Gartner recently increased its worldwide IT spending forecast for 2012 to $3.6 trillion, anticipating a 3 percent increase from 2011 spending.   One of the segments most reliant on technology to catapult growth is midsize companies – established businesses leveraging every competitive efficiency and advantage to compete with much larger enterprises. We find that to compete against the big guys, they need to create an internal technology infrastructure to fuel that growth. Goodbye, spreadsheets and hello modern ERP.   While many businesses postponed upgrading or replacing financial and HR management systems during the recession, now some have started dusting off RFPs and revisiting technology options. Years ago, midsize organizations used spreadsheet-based systems and processes to manage employees, customers, partners, products and revenue. We’ve found that as companies scale up, they are apt to avoid heavily customizing their existing systems, and instead are more prone to standardize on a modern, enterprise-class ERP system.   Modern ERP platforms enable growing companies to immediately address the most pressing challenges – accounting, talent management, customer retention, et. al. Midsize companies implement these systems and processes to help them earn more, go public or expand globally.   And today, choice is a primary factor when selecting an ERP solution. Businesses have more deployment options now than ever before, depending on their unique structures and needs. Whether the preference is on demand, cloud, hosted or on premise, a modular, scalable deployment is available to meet the need.   With modern ERP systems, business that once struggled to do more with fewer resources have access to the same quality tools as larger competitors. By adopting top tier ERP systems tailored to individual business needs, midsize companies can support business operations while creating an enterprise system that seamlessly scales up to fuel future growth. Meaning that the ERP decision that your company makes today, will have legs to serve your business for years to come.

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  • How do you automate a SharePoint 2010 deployment?

    - by Enrique Lima
    In the last couple of months SharePoint traffic (consulting, training and speaking) has picked up.  And with that also the requests for deployments.  There are good, great, bad and really bad things around this. But that is for another topic.  However part of the good and great has been the fact of organizations wanting to do a proof of concept deployment (even when WSS or MOSS has been deployed). We can go through a session (Microsoft has the SDPS concept, SharePoint Deployment Planning Services) of discovering what the customer wants to achieve from their investment in the platform and then also proceed to model the solution that would fit their needs.  But it should not stop there.  The next step should be a POC (as many have requested) to test out. Now, on to the meat of this post.  How do I deploy?  While it is a good process to watch and see all of it take place, not many have the time to sit through that.  Even more so, when that has been part of the description of deploying the platform in the sessions mentioned above. I will, though, break it into a deployment for development purposes and a deployment of a farm. Two tools (or scripts) for those two different types of deployment. First, let me address the development environment.  Around the last week in October, Chris Johnson (SharePoint Product Team) announced a SharePoint Easy Setup for Developers.  The kit itself will assist you in installing SharePoint Server (in standalone mode), the tools that go around Visual Studio, Expression Studio and the Office 2010 tools. Here is the link to Chris’ post: http://blogs.msdn.com/b/cjohnson/archive/2010/10/28/announcing-sharepoint-easy-setup-for-developers.aspx The other scenario is the use of a script in assisting you through the deployment of a farm. Now, this is not to override planning.  It should highlight the need for planning even more.  How?  Having your service accounts planned, the structure of the sites and the scale of your deployment.  Enter AutoSPInstaller.  This is a CodePlex project, and the intent behind this is not only to automate the installation but to give some meaning and get some sense out of what goes on during a SharePoint deployment. How?  Take for example the creation of the databases, when we do the initial OOB deployment by using the wizard, more times than not, we leave the names as they are.  How is that a “bad thing”?  Let’s make it a better practice to rename those Databases, and have them take on a name that is not “GUID-ized”. Having a better naming convention will not hurt, on the other hand will allow for consistency. Here is the link to AutoSPInstaller’s site on CodePlex: http://autospinstaller.codeplex.com/

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  • Seven Accounting Changes for 2010

    - by Theresa Hickman
    I read a very interesting article called Seven Accounting Changes That Will Affect Your 2010 Annual Report from SmartPros that nicely summarized how 2010 annual financial statements will be impacted.  Here’s a Reader’s Digest version of the changes: 1.  Changes to revenue recognition if you sell bundled products with multiple deliverables: Old Rule: You needed to objectively establish the “fair value” of each bundled item. So if you sold a dishwasher plus installation and could not establish the fair value of the installation, you might have to delay recognizing revenue of the dishwasher days or weeks later until it was installed. New Rule (ASU 2009-13): “Objective” proof of each service or good is no longer required; you can simply estimate the selling price of the installation and warranty. So the dishwasher vendor can recognize the dishwasher revenue immediately at the point of sale without waiting a few weeks for the installation. Then they can recognize the estimated value of the installation after it is complete. 2.  Changes to revenue recognition for devices with embedded software: Old Rule: Hardware devices with embedded software, such as the iPhone, had to follow stringent software revrec rules. This forced Apple to recognize iPhone revenues over two years, the period of time that software updates were provided. New Rule (ASU 2009-14): Software revrec rules no longer apply to these devices with embedded software; these devices can now follow ASU 2009-13. This allows vendors, such as Apple, to recognize revenue sooner. 3.  Fair value disclosures: Companies (both public and private) now need to spend extra time gathering, summarizing, and disclosing information about items measured at fair value, such as significant transfers in and out of Level 1(quoted market price), Level 2 (valuation based on observable markets), and Level 3 (valuations based on internal information). 4.  Consolidation of variable interest entities (a.k.a special purpose entities): Consolidation rules for variable interest entities now require a qualitative, not quantitative, analysis to determine the primary beneficiary. Instead of simply looking at the percentage of voting interests, the primary beneficiary could have less than the majority interests as long as it has the power to direct the activities and absorb any losses.  5.  XBRL: Starting in June 2011, all U.S. public companies are required to file financial statements to the SEC using XBRL. Note: Oracle supports XBRL reporting. 6.  Non-GAAP financial disclosures: Companies that report non-GAAP measures of performance, such as EBITDA in SEC filings, have more flexibility.  The new interpretations can be found here: http://www.sec.gov/divisions/corpfin/guidance/nongaapinterp.htm.  7.  Loss contingencies disclosures: Companies should expect additional scrutiny of their loss disclosures, such as those from litigation losses, in their annual financial statements. The SEC wants more disclosures about loss contingencies sooner instead of after the cases are settled.

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  • "ODM" - One of the Support team's most valued acronyms

    - by graham.mckendry(at)oracle.com
    If you submit technical service requests (SRs) through the My Oracle Support portal, you may often see the term "ODM" used in updates from our Support team. ODM is an acronym for "Oracle Diagnostic Methodology", which defines a standard problem solving approach that all of Oracle Support uses for every technical SR. ODM provides a number of benefits to the SRs - both for the Support organization and for the customer - including a consistent approach, higher quality, justified solutions, and ultimately faster resolution. Screenshot: Example of an ODM "Issue Clarification" activity in a service request The Oracle Diagnostic Methodology applies to both categories of technical SRs: Consultative (question-answer topics) and Problem-Solution. There are a few KM Notes that describe the steps of ODM, however to keep things simple (and since those KM Notes appear to be a bit outdated), I'll summarize the ODM stages here as follows: Consultative ODM - Three mandatory stages: ODM Question: Clarification of the customer's exact question. ODM Answer: Thorough answer to the customer's question. ODM Knowledge Content: Reference to new or existing knowledge base content, or explanation why the particular SR does not necessarily require knowledge content. Problem-Solution ODM - Eight mandatory stages: ODM Issue Clarification: Clarification of the reported issue, including the symptoms, the steps to reproduce, and an outline of the business impact ODM Issue Verification: Confirmation of the issue being verified based on proof provided by the customer, such as screenshots, log files, or reproducing the issue during an Oracle Web Conference. ODM Cause Determination: Succinct outline of the root cause of the issue. ODM Cause Justification: Explanation as to why the root cause applies to this particular situation. ODM Proposed Solution(s): Succinct outline of the potential solution(s) to resolve the issue. ODM Proposed Solution(s) Justification: Explanation of why the proposed solution(s) will in fact resolve the issue. ODM Solution Action Plan: Detailed numbered instructions on how to execute the proposed solutions. ODM Knowledge Content: Reference to new or existing knowledge base content, or explanation why the particular SR does not necessarily require knowledge content. During these stages, you may see other optional ODM-related activities such as "ODM Data Collection", "ODM Action Plan", "ODM Research", and "ODM Test Case". Again, these structured tags help ensure a uniform methodology across your SRs. With this knowledge you should be able to develop better predictability of what's coming next in your SRs, as well as what you can do to help expedite the resolution process.

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  • eSTEP Newsletter for October 2013 Now Available

    - by Cinzia Mascanzoni
    The October'13 issue of our Newsletter is now available. The issue contains information on the following topics: Oracle Open World Summary Oracle Cloud: Oracle Engineered Systems Oracle Database and Middleware Oracle Applications and Software as a Service Oracle Industries Oracle Partners and the "Internet of Things" JavaOne News MySQL News Corporate News Create Your HR Strategic Vision at Oracle HCM World Oracle Database Protection Redefined A Preview: Oracle Database Backup Logging Recovery Appliance Oracle closed Tekelec acquisition Congratulations to ORACLE TEAM USA! Tech sectionARC M6 Oracle's SPARC M6 Oracle SuperCluster M6-32 - Oracle’s Most Scalable Engineered System Oracle Multitenant on SPARC Servers and Oracle Solaris Oracle Database 12c Enterprise Edition: Plug into the Cloud Oracle In-Memory Database Cache Oracle Virtual Compute Appliance New Benchmark-Results published (Sept. 2013) Video Interview: Elasticity, the Biggest Challenge Facing Data Centers Today Tech blog Announcing New Sun Storage 2500-M2 Drives SPARC Product Line Update ZFS RAID Calculator v6 What ships with ODA X3-2? Tech Article: Oracle Multitenant on SPARC Servers and Oracle Solaris New release of Sun Rack II capacity calculator available Announcing: Oracle Solaris Cluster Product Bulletin, September 2013 Learning & events Planned TechCasts Quarterly Partner Update Live Webcast: Simplify and Accelerate Oracle Database deployment with Oracle VM Templates Join us for OTN's Virtual Developer Day - Harnessing the Power of Oracle WebLogic and Oracle Coherence. Learn from OOW 2013 what is going on in Virtualization How to Implementing Early Arriving Facts in ODI, Part I and Part II: Proof of Concept Overview Multi-Factor Authentication in Oracle WebLogic Using multi-factor authentication to protect web applications deployed on Oracle WebLogic. If Virtualization Is Free, It Can't Be Any Good—Right? Looking beyond System/HW SOA and User Interfaces Overcoming the challenges to developing user interfaces in a service oriented References Vodafone Romania Improves Business Agility and Customer Satisfaction, with 10x Faster Business Intelligence Delivery and 12x Faster Processing Emirates Integrated Telecommunications Captures 47% Market Share in a Competitive Market, Thanks to 24/7 Availability Home Credit and Finance Bank Accelerates Getting New Banking Products to Market Extra A Conversation with Java Champion Johan Vos You can find the Newsletter on our portal under eSTEP News ---> Latest Newsletter. You will need to provide your email address and the pin below to get access. Link to the portal is shown below. URL: http://launch.oracle.com/ PIN: eSTEP_2011 Previous published Newsletters can be found under the Archived Newsletters section and more useful information under the Events, Download and Links tab.

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  • In Technology, Ignorance is NOT Bliss

    - by Tanu Sood
    Author: Debra Lilley, ACE Director, UK Proof I’m not technical -  I’ve just finished a Latin America tour with OTN and a funny thing happened that I want to share with you; because it is quite a good analogy for how many of us use technology today and you know how I love analogies. In Costa Rica we had a really long journey up through the mountains to where our conference was to be. The road was windy and narrow and once it got dark there was no scenery to see, boredom set in. At one stage I looked at my watch to see the time, but in the dark I couldn’t make it out, so I thought I would be clever and use the torch in my smartphone! Even though as soon as I switched on the phone it showed the time, I ignored it and used the torch to read my watch. That’s us when we pay maintenance on software, ask for enhancements, and either chose not to upgrade or as I have seen so many times, upgrade but don’t use the new features. I know there are always other factors not least the upgrade costs themselves but in the later releases of all the Oracle family of applications Oracle have done a lot to make the interoperability of them with Oracle Fusion Middleware more successful and in many cases for the first time. My heritage is Oracle E Business Suite (EBS) and the availability of Oracle Weblogic for EBS is fantastic for an Oracle powered organisation that can move away from supporting multiple flavours of application server. The same release made available  - the no downtime patching that Oracle Database 11g introduced with Edition Based Redefinition. I am not saying you must use these features but you must be aware of what each release of your application brings and make a business based decision as to whether it is for you or not. I like to have a simple spreadsheet of features with no-value, nice-to-have, must-have ratings, but make the spreadsheet cumulative so that when you do upgrade you have all the features listed you previously didn’t take up. That way you can avoid the ‘using your phone to read your watch’ scenario. About the Author: Debra Lilley, Fusion Champion, UKOUG Board Member, Fusion User Experience Advocate and ACE Director. Lilley has 18 years experience with Oracle Applications, with E Business Suite since 9.4.1, moving to Business Intelligence Team Lead and Oracle Alliance Director. She has spoken at over 100 conferences worldwide and posts at debrasoraclethoughts  

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  • Understanding the levels of computing

    - by RParadox
    Sorry, for my confused question. I'm looking for some pointers. Up to now I have been working mostly with Java and Python on the application layer and I have only a vague understanding of operating systems and hardware. I want to understand much more about the lower levels of computing, but it gets really overwhelming somehow. At university I took a class about microprogramming, i.e. how processors get hard-wired to implement the ASM codes. Up to now I always thought I wouldn't get more done if learned more about the "low level". One question I have is: how is it even possible that hardware gets hidden almost completely from the developer? Is it accurate to say that the operating system is a software layer for the hardware? One small example: in programming I have never come across the need to understand what L2 or L3 Cache is. For the typical business application environment one almost never needs to understand assembler and the lower levels of computing, because nowadays there is a technology stack for almost anything. I guess the whole point of these lower levels is to provide an interface to higher levels. On the other hand I wonder how much influence the lower levels can have, for example this whole graphics computing thing. So, on the other hand, there is this theoretical computer science branch, which works on abstract computing models. However, I also rarely encountered situations, where I found it helpful thinking in the categories of complexity models, proof verification, etc. I sort of know, that there is a complexity class called NP, and that they are kind of impossible to solve for a big number of N. What I'm missing is a reference for a framework to think about these things. It seems to me, that there all kinds of different camps, who rarely interact. The last few weeks I have been reading about security issues. Here somehow, much of the different layers come together. Attacks and exploits almost always occur on the lower level, so in this case it is necessary to learn about the details of the OSI layers, the inner workings of an OS, etc.

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  • What is the standard term for my role?

    - by sigil
    I'm doing work that involves writing code and managing developers in a "special projects" division of a large company. I'd like to define my role better and figure out if there's an industry standard term for what I do, so that it will be easier for me to research best practices and work on a career path What I do all day: A macro that connects an Excel sheet to an Access database is acting funny; I get called in to figure out what's happening and debug it. Someone needs data extracted from a bunch of files on Sharepoint. I figure out a client-side solution because I'm not authorized to do anything server-side and getting IT to do anything would take several months and need a business case. A manager wants a new data entry tool for their team. I interview the manager and team members to work out the functional requirements, then design/develop/test the application. Someone needs a VBA script to crunch some data for their presentation that's due in two hours. I drop everything I'm doing to hack out a quick script and run the analysis, without much in the way of testing. A developer has been hired to build a database for one of the teams, since I'm working on too many different things and don't have time to take this project on in the timeframe required. I direct his work and push him to meet certain deadlines, interview stakeholders to get more info that will help him figure out how to build the necessary forms, and modify the functional requirements of the database to fit in the timeframe. Someone wants to load a set of data into a GIS system and set up an ongoing refresh and reporting of this data set. I facilitate the conversation between the GIS developers and the owners of this data set, and design a demo application as proof of concept. It's kind of an "all-purpose programming and IT management" position, but it's not officially IT because the company has an actual IT department with a rigorously defined system of submitting requests, developing code, and managing projects. What I do, I guess, is more of a handyman job, where stuff falls to me because I'm the geekiest one in the room. Is there a standard term in the software world for what I do?

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  • Hyper-V Server 2012 with Zambezi AMD FX-Series - Hardware assisted virtualization not present

    - by Vazgen
    I'm trying to set up VDI across Windows Server 2012 VMs running on Hyper-V 2012. The wizard's compatibility check for the Virtualization Host server failed with "Hardware-assisted virtualization is not present on the server". I'm running an FX-8120 CPU and have the ASUS M5A97 motherboard. I know I'm supposed to enable No-Execute (Hyper-V Hardware Considerations) but I cannot find that or any other synonyms of it in my motherboards UEFI BIOS (NX, XD, EVP, XN... nothing). I found this: PAE/NX/SSE2 Support Requirement Guide for Windows 8 which in short says "Windows 8 and Windows Server 2012 requires that systems must have processors that support NX, and NX must be turned on for important security safeguards to function effectively and avoid potential security vulnerabilities." this leads me to believe NX is on by default if I was able to get this far and install Hyper-V 2012 and Windows Server 2012.. Also I tried to disable AVX in cmd with "bcdedit /set xsavedisable 1". Did not resolve My processor is Zambezi FX-8120 and also supports RVI/SLAT/other synonym: processor: Newegg Processor FX-8120 support proof: AMD Processors with Rapid Virtualization Indexing Required to Run Hyper-V in Windows 8 What's going on here? I bought this CPU specifically after I had the same problems with an older AMD Athelon II and made sure to buy one with AMD-V and RVI. Thank you

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  • CopSSH SFTP -- limit users access to their home directory only

    - by bradvido
    Let me preface this by saying I've read and followed these instructions at the FAQ many times: http://www.itefix.no/i2/node/37 It does not do what the title claims... It allows every user access to every other user's home directory, as well as access to all subfolders below the copssh installation path. I'm only using this for SFTP access and I need my users to be sandboxed into only their home directory. If you know a fool-proof way to lock users down so they can see only their home directory and its subfolders, stop reading now and reply with the solution. The details: Here is exactly what i tried as I followed the FAQ. My copSSH installation directory is: C:\Program Files\CopSSH net localgroup sftp_users /ADD **Create a user group to hold all my SFTP users cacls c:\ /c /e /t /d sftp_users **For that group, deny access at the top level and all levels below cacls "C:\Program Files\CopSSH" /c /e /t /r sftp_users **Allow my user group access to the copSSH installation directory and its subdirectories For each sftp user, I create a new windows user account, then I: net localgroup sftp_users sftp_user_1 /add **Add my user to the group I've created Open the activate user wizard for CopSSH, choosing the user, "/bin/sftponly" and Remove copssh home directory if it exists **Remains checked Create keys for public key authentication **Remains checked Create link to user's real home directory **Remains checked This works, however, every user has access to every other user's home directory as well as the CopSSH root directory.... So I tried denying access for all users to the user home directory: cacls "C:\Program Files\CopSSH\home" /c /e /t /d sftp_users **Deny access for users to the user home directory Then I tried adding permissions on a user-by-user basis for each users home\username folder. However,these permission were not allowed by windows because of the above deny rule i created at the home directory was being inherited and over-riding my allow rule. The next step for me would be to remove the deny rule at the home directory and for each user folder, add a deny rule for every user it doesn't belong to, and add an allow rule for the one user it does belong to. However, as my user list gets long, this will become very cumbersome. Thanks for the help!

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  • Confusion about Kerberos, delegation and SPNs.

    - by Vilx-
    I already posted this question on SO, but the nature of it is between programming and server configuration, so I'll re-post it here as well. I'm trying to write a proof-of-concept application that performs Kerberos delegation. I've written all the code, and it seems to working (I'm authenticating fine), but the resulting security context doesn't have the ISC_REQ_DELEGATE flag set. So I'm thinking that maybe one of the endpoints (client or server) is forbidden to delegate. However I'm not authenticating against an SPN. Just one domain user against another domain user. As the SPN for InitializeSecurityContext() I'm passing "[email protected]" (which is the user account under which the server application is running). As I understand, domain users have delegation enabled by default. Anyway, I asked the admin to check, and the "account is sensitive and cannot be delegated" checkbox is off. I know that if my server was running as a NETWORK SERVICE and I used an SPN to connect to it, then I'd need the computer account in AD to have the "Trust computer for delegation" checkbox checked (off by default), but... this is not the case, right? Or is it? Also - when the checkbox in the computer account is set, do the changes take place immediately, or must I reboot the server PC or wait for a while?

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  • Nginx dynamic upstream configuration / routing

    - by Dan Sosedoff
    I was experimenting with dynamic upstream configuration for nginx and cant find any good solution to implement upstream configuration from third-party source like redis or mysql. The idea behind it is to have a single file configuration in primary server and proxy requests to various app servers based on environment conditions. Think of dynamic deployments where you have X servers that are running Y workers on different ports. For instance, i create a new app and deploy. App manager selects a server and then rolls out a worker (Ruby/PHP/Python) and then reports the ip:port to the central database with status "up". At this time when i go to the given url nginx should proxy all requests to the specified ip:port upstream. The whole thing is pretty similar to what heroku does, except this proof-of-concept is not supposed to be production ready, mostly for internal needs. The easiest solution i found was using resolver with ruby-based DNS server. It works, nginx gets the IP address correctly, but the only problem is that you cant define port number for that IP. Second solution (which i havent tried yet) is to roll something else as a proxy server, maybe written in Erlang. In this case we need to use something to serve static content. Any ideas how to implement this in more flexible and stable way? P.S. Some research options: http://openresty.org/#DynamicRoutingBasedOnRedis https://github.com/nodejitsu/node-http-proxy

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  • Network corruption - corrupt downloads, corrupt streams, etc.

    - by rfrankel
    I've been having some problems with my home LAN. Downloaded executables won't run, my remote desktop sessions keep getting interrupted due to encryption errors, flash video streams show visible corruption (both Hulu and YouTube), and I've had a couple downloads for which the md5 hashes don't match. The problem has even occurred with a couple images embedded in webpages, though that's rare enough (presumably because images are relatively smaller files). I've had this problem across two Windows machines and a Mac, so it's neither machine-specific nor at the app or OS level. Comcast claims it's nothing to do with them, and my Linksys/Cisco RV016 router is out of warranty, so I have no access to official support. When I log into my router, it shows no error packets or dropped packets received. I plugged a laptop directly into the router and was able to download a 5.5 MB file and verify its MD5 hash, which is not proof that the problem is downstream of the router, but makes it seem quite likely, since I failed to download the same file several times from two desktops (one Mac, one Windows). Could this be a wiring problem? If so, is there any way clever/elegant to determine which wiring is faulty with just software? If I can avoid tracing all the wires throughout my entire house it would make my life quite a bit easier.

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  • Server high memory usage at same time every day

    - by Sam Parmenter
    Right, we moved one of our main sites onto a new AWS box with plenty of grunt as it would allow us more control that we had before and future proof ourselves. About a month ago we started running into issues with high memory usage at the same time every day. In the morning an export is run to export data to a file which is the FTPed to a local machine for processing. The issues were co-inciding with the rough time of the export but when we didn't run the export one day, the server still ran into the same issues. The export has been run at other times in the day since to monitor memory usage to see if it spikes. The conclusion is that the export is fine and barely touches the sides memory wise. No noticeable change in memory usage. When the issue happens, its effect is to kill mysql and require us to restart the process. We think it might be a mysql memory issue, but might just be that mysql is just the first to feel it. Looking at the logs there is no particular query run before the memory usage hits 90%. When it strikes at about 9:20am, the memory usage spikes from a near constant 25% to 98% and very quickly kills mysql to save itself. It usually takes about 3-4 minutes to die. There are no cron jobs running at that time of the day and we haven't noticed a spike in traffic over the period of the issues. Any help would be massively appreciated! thanks.

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  • XAMPP CURL not working!

    - by MiffTheFox
    Nope, it's not. Windows Vista Home Premium x32: Relevant section of php.ini: ; Windows Extensions ; Note that ODBC support is built in, so no dll is needed for it. ; Note that many DLL files are located in the extensions/ (PHP 4) ext/ (PHP 5) ; extension folders as well as the separate PECL DLL download (PHP 5). ; Be sure to appropriately set the extension_dir directive. ;extension=php_apc.dll ;extension=php_apd.dll ;extension=php_bcompiler.dll ;extension=php_bitset.dll ;extension=php_blenc.dll ;extension=php_bz2.dll ;extension=php_bz2_filter.dll ;extension=php_classkit.dll ;extension=php_cpdf.dll ;extension=php_crack.dll extension=php_curl.dll ;extension=php_cvsclient.dll ;extension=php_db.dll ;extension=php_dba.dll ;extension=php_dbase.dll ;extension=php_dbx.dll Proof it's not working: c:\users\miff>curl http://localhost/xampp/phpinfo.php | grep curl % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 62592 0 62592 0 0 1971k 0 --:--:-- --:--:-- --:--:-- 3319k <tr><td class="e">HTTP_USER_AGENT </td><td class="v">curl/7.16.3 (i686-pc-cygwin) libcurl/7.16.3 OpenSSL/0.9.8k zlib/1.2.3 libssh2/0.15-CVS </td></tr> <tr><td class="e">User-Agent </td><td class="v">curl/7.16.3 (i686-pc-cygwin) libcurl/7.16.3 OpenSSL/0.9.8k zlib/1.2.3 libssh2/0.15-CVS </td></tr> <tr><td class="e">_SERVER["HTTP_USER_AGENT"]</td><td class="v">curl/7.16.3 (i686-pc-cygwin) libcurl/7.16.3 OpenSSL/0.9.8k zlib/1.2.3 libssh2/0.15-CVS</td></tr> c:\users\miff>

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  • CopSSH SFTP -- limit users access to their home directory only

    - by bradvido
    Let me preface this by saying I've read and followed these instructions at the FAQ many times: http://www.itefix.no/i2/node/37 It does not do what the title claims... It allows every user access to every other user's home directory, as well as access to all subfolders below the copssh installation path. I'm only using this for SFTP access and I need my users to be sandboxed into only their home directory. If you know a fool-proof way to lock users down so they can see only their home directory and its subfolders, stop reading now and reply with the solution. The details: Here is exactly what i tried as I followed the FAQ. My copSSH installation directory is: C:\Program Files\CopSSH net localgroup sftp_users /ADD **Create a user group to hold all my SFTP users cacls c:\ /c /e /t /d sftp_users **For that group, deny access at the top level and all levels below cacls "C:\Program Files\CopSSH" /c /e /t /r sftp_users **Allow my user group access to the copSSH installation directory and its subdirectories For each sftp user, I create a new windows user account, then I: net localgroup sftp_users sftp_user_1 /add **Add my user to the group I've created Open the activate user wizard for CopSSH, choosing the user, "/bin/sftponly" and Remove copssh home directory if it exists **Remains checked Create keys for public key authentication **Remains checked Create link to user's real home directory **Remains checked This works, however, every user has access to every other user's home directory as well as the CopSSH root directory.... So I tried denying access for all users to the user home directory: cacls "C:\Program Files\CopSSH\home" /c /e /t /d sftp_users **Deny access for users to the user home directory Then I tried adding permissions on a user-by-user basis for each users home\username folder. However,these permission were not allowed by windows because of the above deny rule i created at the home directory was being inherited and over-riding my allow rule. The next step for me would be to remove the deny rule at the home directory and for each user folder, add a deny rule for every user it doesn't belong to, and add an allow rule for the one user it does belong to. However, as my user list gets long, this will become very cumbersome. Thanks for the help!

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  • Does Windows 8 RTM Support VB6 (SP6) Runtime files? If so, which ones?

    - by user51047
    Basically, I'm trying to find out which of the following files come packaged with the Windows 8 RTM (that is, the final version). Just to be clear, we're not wanting to know if any of the runtime files (listed below) are or were included with any of the previous versions (Beta, CTP, RS etc) or releases of Windows 8 - we are just interested in this compatibility question as far as Windows 8 RTM (Final Version) is concerned. In addition, if possible, we would also like to know which of the below files (if any) come shipped and registered with the Windows 8 RT (on ARM) version. As far as the ARM version is concerned, you're welcome to base your answer on the latest version of Windows 8 RT (on ARM) that is available at the date and time your answer is posted. (This will also serve to future-proof this question as additional releases or versions of Windows 8 and Windows 8 RT on ARM come out). Here are the list of files (which are basically the VB6 SP6 runtime files): File name Version Size Asycfilt.dll 2.40.4275.1 144 KB (147,728 bytes) Comcat.dll 4.71.1460.1 21.7 KB (22,288 bytes) Msvbvm60.dll 6.0.97.82 1.32 MB (1,386,496 bytes) Oleaut32.dll 2.40.4275.1 584 KB (598,288 bytes) Olepro32.dll 5.0.4275.1 160 KB (164,112 bytes) Stdole2.tlb 2.40.4275.1 17.5 KB (17,920 bytes) Of course, the most important file in there is MSVBVM60.DLL, so if you cannot provide details for all files relating to both Windows Releases, then basing the answer on as many of the files possible would also be useful. Thank you for reading and for your anticipated assistance in putting this question/answer on record.

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  • Hiding a Website from Search Engine Bots and Viewers by Disabling Default VirtualHost

    - by Basel Shishani
    When staging a website on a remote VPS, we would like it to be accessible to team members only, and we would also like to keep the search engine bots off until the site is finalized. Access control by host whether in Iptables or Apache is not desirable, as accessing hosts can vary. After some reading in Apache config and other SF postings, I settled on the following design that relies on restricting access to only through specific domain names: Default virtual host would be disabled in Apache config as follows - relying on Apache behavior to use first virtual host for site default: <VirtualHost *:80> # Anything matching this should be silently ignored. </VirtualHost> <VirtualHost *:80> ServerName secretsiteone.com DocumentRoot /var/www/secretsiteone.com </VirtualHost> <VirtualHost *:80> ServerName secretsitetwo.com ... </VirtualHost> Then each team member can add the domain names in their local /etc/hosts: xx.xx.xx.xx secrethostone.com My question is: is the above technique good enough to achieve the above said goals esp restricting SE bots, or is it possible that bots would work around that. Note: I understand that mod_rewrite rules con be used to achieve a similar effect as discussed here: How to disable default VirtualHost in apache2?, so the same question would apply to that technique too. Also please note: the content is not highly secretive - the idea is not to devise something that is hack proof, so we are not concerned about traffic interception or the like. The idea is to keep competitors and casual surfers from viewing the content before it's released, and to prevent SE bots from indexing it.

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  • EXCEL generate a character in one column of a row, only if other columns in the same row are not bl

    - by Simon
    My speadsheet keeps track of when patients leave a specific floor of the hospital. There are columns in which where each patient goes is documented (1 column for "home", another column for "rehab facility", another for "other floor", etc.). Only when the patient leaves the hospital altogether does it count as a discharge, in which case the “discharge” column needs to have something in it. What formula can I use to generate, say, an "x" in the "discharge" column if certain "where they went" columns in the same row contain something, but not if there is nothing in any of them? Currently, to accomplish this I am using =IF(OR(M30,N30,O30,P30,Q30,R30,S30),"x") in row 3 of the "discharge" column (rows 1 and 2 are headings), and I have used "fill down" in all subsequent rows. To suppress the "FALSE" this formula yields when the condition is not true, I have applied conditonal formatting to the entire column that if the value=FALSE then the font is white (same colour as background). Is there a more efficient, elegant and idiot-proof way of doing this? The conditional formatting of text colour could potentially confuse everyone but the person who built the spreadsheet (me).

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  • Keyboards for kiosk/outdoor/abusive environments?

    - by Justin Scott
    We have a bunch of kiosks deployed into let's just say... abusive environments. The enclosures we had built are touch as nails, and the HP thin client computers are working great. The keyboards that were purchased for the project have been nothing but problems. They're a generic brand direct from a Chinese manufacturer. They're stainless steel with keys mounted from the inside and a trackball, but they've been deployed for only a month and nearly 20% of them are already out of service due to keys sticking, keys not working, trackball problems, water damage, and a variety of other issues. Are there any kiosk keyboards that can take a beating without breaking so easily? Ideally they should be tamper-proof (keys can't be removed), waterproof, lettering should be engraved into the keys, trackball, option for a single mouse button would be nice, and some protection to keep debris out of the keys so they don't stick (sticky cleaners, food debris, etc.). Does such a beast exist? Everything we've looked at is susceptible to easy damage. We need the M1 Abrams Tank of keyboards. Any suggestions?

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  • Tracking Security Vulnerability remediation

    - by Zypher
    I've been looking into this for a little while, but havn't really found anything suitable. What I am looking for is a system to track security vulnerability remdiation status. Something like "bugzilla for IT" What I am looking for is something pretty simple that allows the following: batch entry of new vulnerabilities that need to be remediated Per user assignment AD/LDAP Authentiation Simple interface to track progress - research, change control status, remediated, etc. Historical search ability Ability to divide by division Ability to store proof of resolution for the Security Team to access Dependency tracking Linux based is best (that's my group :) ) Free is good, but cost doesn't matter so much if the system is worth it The systems doesn't have to have all of these features, but if it did that would be great. yes we could use our helpdesk software, but that has a bunch of pitfalls such as triggering SLA alerts and penalties as well as not easily searchable outside of a group. Most of what I have found are bug tracking systems that are geared towards developers, and are honstely way overkill for what I am looking for. Server Faults input is greatly appreciated as always!

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