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  • Using Microsoft Excel as a Source and a Target in Oracle Data Integrator

    - by julien.testut
    The posts in this series assume that you have some level of familiarity with ODI. The concepts of Models, Datastores, Logical Schema, Knowledge Modules and Interfaces are used here assuming that you understand them in the context of ODI. If you need more details on these elements, please refer to the ODI Tutorial for a quick introduction, or to the complete ODI documentation for more details. Recently we saw how to create a create a connection to Microsoft Excel let's now take a look at how we can use Microsoft Excel as a source or a target in ODI interfaces. Create a Model in Designer First we need to create a new Model and a datastore for our Microsoft Excel spreadsheet. In Designer open up the Models view and insert a new Model. Give a name to your model, I used EXCEL_SRC_CITY.

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  • LXDE keybind "Raise" window not working

    - by Campa
    I am using LXDE* over Ubuntu Oneiric on a DELL Studio-XPS 64-bit machine and I can't get the keybind for raising windows to work. In my ~/.config/openbox/lxde-rc.xml I put: <!-- Iconify window: it works. --> <keybind key="A-Down"> <action name="Iconify"/> </keybind> <!-- Raise window: does nothing. --> <keybind key="A-Up"> <action name="Focus"/> <action name="Raise"/> </keybind> then I openbox --reconfigure, but no rasing windows keybindings. I could use the NextWindow action, but... not really the same. References: http://openbox.org/wiki/Help:Bindings http://openbox.org/wiki/Help:Actions *Nested question: how to know the version of installed LXDE?

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  • Connect to MySQL on remote server from inside python script (DB API)

    - by Atul Kakrana
    Very recently I have started to write python scripts that need to connect few databases on mySQL server. The problem is that when I work from office my script works fine but running a script from my home while on office VPN generates connection error. I also noticed the mySQL client Squirrel also cannot connect from my home but works fine on Office computer. I think both are giving problem for the same reason. Do I need to create a ssh tunnel and forward the port? If yes how do I do it? mySQL is installed on server I have ssh access. Please help me on this AK

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  • Error installing RVM

    - by Dbugger
    I am following this guide, but this is the output I receive. What am the problem? dbugger@mercury:~$ \curl -sSL https://get.rvm.io | bash -s stable --rails Downloading https://github.com/wayneeseguin/rvm/archive/stable.tar.gz Upgrading the RVM installation in /home/dbugger/.rvm/ RVM PATH line found in /home/dbugger/.profile /home/dbugger/.bashrc /home/dbugger/.zshrc. RVM sourcing line found in /home/dbugger/.bash_profile /home/dbugger/.zlogin. Upgrade of RVM in /home/dbugger/.rvm/ is complete. # Enrique, # # Thank you for using RVM! # We sincerely hope that RVM helps to make your life easier and more enjoyable!!! # # ~Wayne, Michal & team. In case of problems: http://rvm.io/help and https://twitter.com/rvm_io Upgrade Notes: * No new notes to display. rvm 1.25.27 (stable) by Wayne E. Seguin <[email protected]>, Michal Papis <[email protected]> [https://rvm.io/] Searching for binary rubies, this might take some time. No binary rubies available for: ubuntu/14.04/x86_64/ruby-2.1.2. Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies. Checking requirements for ubuntu. Installing requirements for ubuntu. Updating system.......... Installing required packages: gawk, libreadline6-dev, libssl-dev, libyaml-dev, libsqlite3-dev, sqlite3.... Error running 'requirements_debian_libs_install gawk libreadline6-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3', showing last 15 lines of /home/dbugger/.rvm/log/1401804140_ruby-2.1.2/package_install_gawk_libreadline6-dev_libssl-dev_libyaml-dev_libsqlite3-dev_sqlite3.log ++ /scripts/functions/utility : __rvm_try_sudo() 405 > sudo -p '%p password required for '\''apt-get --no-install-recommends --yes install gawk libreadline6-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3'\'': ' apt-get --no-install-recommends --yes install gawk libreadline6-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3 Reading package lists... Building dependency tree... Reading state information... Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: libssl-dev : Depends: libssl1.0.0 (= 1.0.1f-1ubuntu2) but 1.0.1f-1ubuntu2.1 is to be installed E: Unable to correct problems, you have held broken packages. ++ /scripts/functions/utility : __rvm_try_sudo() 405 > return 100 ++ /scripts/functions/requirements/ubuntu : requirements_debian_libs_install() 36 > return 100 Requirements installation failed with status: 100.

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  • What tools are available to generate end user documentation?

    - by Rowland Shaw
    End user documentation on how to use applications is an important part of the user experience of applications, irrespective of whether they are winforms, wpf or even asp applications. In a startup or internal development team situation, where there isn't a dedicated documentation department, it can take a lot of resources to maintain screen shots and associated user documentation, such as on-line help or even printable manuals. What tools are available to assist in creating screenshots of all the "screens" within an application (be they winforms, wpf or aspx) to help automate the capture of screen shots, and associating with the relevant documentation? In addiiton, are there any that allow automation of annotations of a particular control (so use cases like: Draw a red box around the Username control with a callout to say "This is where you'd enter your user name, in the form '[email protected]'")?

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  • Making file in user's homedir accessible from web/webserver

    - by evident
    Hi everybody, I have a txt-file one of my user's homedir which is regularly updated there by a script. I now want to be able to access (read) this file from the web. /home/user/folder/file.txt So what I tried now is to log in as root, go into my webservers httpdocs folder /var/www/path/to/domain/httpdocs and there I tried to create a symbolic link with ln -s /home/user/foler/file.txt /var/www/path/to/domain/httpdocs/file.txt But this didn't work... I already tried changing the chmod of the symlink (which changes the ones from the original file of course) and also a chown to the user from webserver, but no matter what I tried I cannot open the file from the web or from a php-script (which is what I want to do) Can anybody help me and tell me what I need to do? What rights do I need to give? Or is there another way of achieving this?

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  • Developing a new complex travel website

    - by Kay
    We need to develop a completely new website for customers to choose a travel product with a contract. It needs to interface to our inventory to take the conference facility, hotel rooms etc. out of inventory once a contract has been signed (e-signature) and deposit paid. If you were starting from scratch, would you in-house or contract? If in-house, what development tools should I evaluate primarily - sharepoint, ASP.net? We are a small IT shop but we could hire 1-2 developers for this. We need to get something up in 12-18 months.

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  • Mail Scanning System

    - by Mr D
    In the same way gmail can generate ads based on email content, I am looking for a way to develop a system which can: Allow users to connect their email address to our site It then would continously monitor all incomming emails From the incomming emails there would be a critera(e.g. a certain address or subject) if any of the emails matched the critea it would would be saved to a database Then once a new email had been found the users would receive an email notification will tells them to log back into the site to see it. My questions are: Would this be possible? What would be a good language to use(generally I like php, python and java) Are there any frameworks which would help do this? How would I connect the users email account to allow access to their emails(do I need a mail server?) Any advice? Thank you! If you need more information please let me know.

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  • How to use TFS as a query tracking system?

    - by deostroll
    We already use tfs for managing defects in code etc, etc. We additionally need a way to "understand the domain & requirements of the products". Normally, without tfs we exchange emails with the consultants and have the questions/queries answered. If it is a feature implementation we sometimes "find" conflicts in the implementation itself. And when that happens the userstory is modified and the enhancement/bug as per that is raised in TFS. Sometimes it is critical we come back to decisions we made or questions we wanted answers to. Hence we need to be able to track how that "requirement idea" or that "query in concern" evolved. Hence how is it that we can use TFS to track all of this? Do we raise an "issue" item for this? Or do we raise a "bug" item? The main things we'd ideally look in a query tracking system are as follows: Area: Can be a module, submodule, domain. Sometimes this may be "General" - to address domain related stuff, or, event more granular to address modules, sub-modules. Take the case for the latter, if we were tracking this in excel sheets, we'd just write module1,submodule2; i.e. in a comma separated fashion. The things I would like here is to be able search for all queries relating to submodule2 sometime in the future. Responses: This is a record of conversations between the consultant and any other stakeholder. For a simple case, it would just be paragraphs. Each para would start with a name and date enclosed in brackets and the response following that...each para would be like a thread - much like a forum thread Action taken: We'd want to know how the query was closed, what was the input given, what were the changes that took place because of that, etc etc. These are fields I think I would need in such a system apart from some obvious ones like status, address to, resovled by, etc. I am open for any other fields which are sort of important. To summarise my question: how can we manage "queries" in the system? Where should we ideally store data pertaining to those three fields I have mentioned above (for e.g. is it wise to store responses in the history tag assuming we are opening a bug for the query)?

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  • Building Queries Systematically

    - by Jeremy Smyth
    The SQL language is a bit like a toolkit for data. It consists of lots of little fiddly bits of syntax that, taken together, allow you to build complex edifices and return powerful results. For the uninitiated, the many tools can be quite confusing, and it's sometimes difficult to decide how to go about the process of building non-trivial queries, that is, queries that are more than a simple SELECT a, b FROM c; A System for Building Queries When you're building queries, you could use a system like the following:  Decide which fields contain the values you want to use in our output, and how you wish to alias those fields Values you want to see in your output Values you want to use in calculations . For example, to calculate margin on a product, you could calculate price - cost and give it the alias margin. Values you want to filter with. For example, you might only want to see products that weigh more than 2Kg or that are blue. The weight or colour columns could contain that information. Values you want to order by. For example you might want the most expensive products first, and the least last. You could use the price column in descending order to achieve that. Assuming the fields you've picked in point 1 are in multiple tables, find the connections between those tables Look for relationships between tables and identify the columns that implement those relationships. For example, The Orders table could have a CustomerID field referencing the same column in the Customers table. Sometimes the problem doesn't use relationships but rests on a different field; sometimes the query is looking for a coincidence of fact rather than a foreign key constraint. For example you might have sales representatives who live in the same state as a customer; this information is normally not used in relationships, but if your query is for organizing events where sales representatives meet customers, it's useful in that query. In such a case you would record the names of columns at either end of such a connection. Sometimes relationships require a bridge, a junction table that wasn't identified in point 1 above but is needed to connect tables you need; these are used in "many-to-many relationships". In these cases you need to record the columns in each table that connect to similar columns in other tables. Construct a join or series of joins using the fields and tables identified in point 2 above. This becomes your FROM clause. Filter using some of the fields in point 1 above. This becomes your WHERE clause. Construct an ORDER BY clause using values from point 1 above that are relevant to the desired order of the output rows. Project the result using the remainder of the fields in point 1 above. This becomes your SELECT clause. A Worked Example   Let's say you want to query the world database to find a list of countries (with their capitals) and the change in GNP, using the difference between the GNP and GNPOld columns, and that you only want to see results for countries with a population greater than 100,000,000. Using the system described above, we could do the following:  The Country.Name and City.Name columns contain the name of the country and city respectively.  The change in GNP comes from the calculation GNP - GNPOld. Both those columns are in the Country table. This calculation is also used to order the output, in descending order To see only countries with a population greater than 100,000,000, you need the Population field of the Country table. There is also a Population field in the City table, so you'll need to specify the table name to disambiguate. You can also represent a number like 100 million as 100e6 instead of 100000000 to make it easier to read. Because the fields come from the Country and City tables, you'll need to join them. There are two relationships between these tables: Each city is hosted within a country, and the city's CountryCode column identifies that country. Also, each country has a capital city, whose ID is contained within the country's Capital column. This latter relationship is the one to use, so the relevant columns and the condition that uses them is represented by the following FROM clause:  FROM Country JOIN City ON Country.Capital = City.ID The statement should only return countries with a population greater than 100,000,000. Country.Population is the relevant column, so the WHERE clause becomes:  WHERE Country.Population > 100e6  To sort the result set in reverse order of difference in GNP, you could use either the calculation, or the position in the output (it's the third column): ORDER BY GNP - GNPOld or ORDER BY 3 Finally, project the columns you wish to see by constructing the SELECT clause: SELECT Country.Name AS Country, City.Name AS Capital,        GNP - GNPOld AS `Difference in GNP`  The whole statement ends up looking like this:  mysql> SELECT Country.Name AS Country, City.Name AS Capital, -> GNP - GNPOld AS `Difference in GNP` -> FROM Country JOIN City ON Country.Capital = City.ID -> WHERE Country.Population > 100e6 -> ORDER BY 3 DESC; +--------------------+------------+-------------------+ | Country            | Capital    | Difference in GNP | +--------------------+------------+-------------------+ | United States | Washington | 399800.00 | | China | Peking | 64549.00 | | India | New Delhi | 16542.00 | | Nigeria | Abuja | 7084.00 | | Pakistan | Islamabad | 2740.00 | | Bangladesh | Dhaka | 886.00 | | Brazil | Brasília | -27369.00 | | Indonesia | Jakarta | -130020.00 | | Russian Federation | Moscow | -166381.00 | | Japan | Tokyo | -405596.00 | +--------------------+------------+-------------------+ 10 rows in set (0.00 sec) Queries with Aggregates and GROUP BY While this system might work well for many queries, it doesn't cater for situations where you have complex summaries and aggregation. For aggregation, you'd start with choosing which columns to view in the output, but this time you'd construct them as aggregate expressions. For example, you could look at the average population, or the count of distinct regions.You could also perform more complex aggregations, such as the average of GNP per head of population calculated as AVG(GNP/Population). Having chosen the values to appear in the output, you must choose how to aggregate those values. A useful way to think about this is that every aggregate query is of the form X, Y per Z. The SELECT clause contains the expressions for X and Y, as already described, and Z becomes your GROUP BY clause. Ordinarily you would also include Z in the query so you see how you are grouping, so the output becomes Z, X, Y per Z.  As an example, consider the following, which shows a count of  countries and the average population per continent:  mysql> SELECT Continent, COUNT(Name), AVG(Population)     -> FROM Country     -> GROUP BY Continent; +---------------+-------------+-----------------+ | Continent     | COUNT(Name) | AVG(Population) | +---------------+-------------+-----------------+ | Asia          |          51 |   72647562.7451 | | Europe        |          46 |   15871186.9565 | | North America |          37 |   13053864.8649 | | Africa        |          58 |   13525431.0345 | | Oceania       |          28 |    1085755.3571 | | Antarctica    |           5 |          0.0000 | | South America |          14 |   24698571.4286 | +---------------+-------------+-----------------+ 7 rows in set (0.00 sec) In this case, X is the number of countries, Y is the average population, and Z is the continent. Of course, you could have more fields in the SELECT clause, and  more fields in the GROUP BY clause as you require. You would also normally alias columns to make the output more suited to your requirements. More Complex Queries  Queries can get considerably more interesting than this. You could also add joins and other expressions to your aggregate query, as in the earlier part of this post. You could have more complex conditions in the WHERE clause. Similarly, you could use queries such as these in subqueries of yet more complex super-queries. Each technique becomes another tool in your toolbox, until before you know it you're writing queries across 15 tables that take two pages to write out. But that's for another day...

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  • All tweak settings not saving after last 2 updates?

    - by mawburn
    I am running Ubuntu GNOME 14.04. After the last 2 updates, all settings in the Tweak menu are no saving. It will also not switch to the Gnome Dark theme at all. This includes all Startup Application changes as well as any changes to Extension settings. I'm not sure if I need to include any sort of log records or anything like that, so if you need any more information please ask. I've noticed the default fonts seem to be different. I don't remember that being part of the theme settings. It's almost like I'm running in Safe Mode.

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  • Why UFW has to be (re)started at boot time if it's only iptables rule manager?

    - by Tomasz Zielinski
    README from source package says: When installing ufw from source, you will also need to integrate it into your boot process for the firewall to start when you restart your system. Depending on your needs, this can be as simple as adding the following to a startup script (eg rc.local for systems that use it): # /lib/ufw/ufw-init start For systems that use SysV initscripts, an example script is provided in doc/initscript.example. See doc/upstart.example for an Upstart example. Consult your distribution's documentation for the proper way to modify your boot process. On my system I have this: # /etc/ufw/ufw.conf # # Set to yes to start on boot. If setting this remotely, be sure to add a rule # to allow your remote connection before starting ufw. Eg: 'ufw allow 22/tcp' ENABLED=yes So, why does simple iptables rule manager need to be started at boot time? Is there any secret to that, or it merely checks if all rules are in place ?

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  • Can an expert examine my .NET MVC 4 application? [on hold]

    - by Till Death Developer
    Problem Definition: I need an expert to examine my application not for errors but have a look at how my implementation goes and tell me whether am doing a good job or am just creating a huge mess, and please me with suggestion on how i should improve my work? Points of Concern: Neat Solution(Can find the thing you are looking for easily). Low Redundancy. Efficiency (Load time, Speed, etc...) Data Access Implementation. Authentication System Implementation. Data Services Implementation. Note: Application is just a playground for testing new implementation approaches so it may seem meaningless because it is, however not the subject any way i just need to know if am doing things in a good way(Nothing is the right way but there is good and bad). Solution Link: http://www.mediafire.com/?8s70y44w16n1uyx

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  • Building an MVC application using QuickBooks

    - by dataintegration
    RSSBus ADO.NET Providers can be used from many tools and IDEs. In this article we show how to connect to QuickBooks from an MVC3 project using the RSSBus ADO.NET Provider for QuickBooks. Although this example uses the QuickBooks Data Provider, the same process can be used with any of our ADO.NET Providers. Creating the Model Step 1: Download and install the QuickBooks Data Provider from RSSBus. Step 2: Create a new MVC3 project in Visual Studio. Add a data model to the Models folder using the ADO.NET Entity Data Model wizard. Step 3: Create a new RSSBus QuickBooks Data Source by clicking "New Connection", specify the connection string options, and click Next. Step 4: Select all the tables and views you need, and click Finish to create the data model. Step 5: Right click on the entity diagram and select 'Add Code Generation Item'. Choose the 'ADO.NET DbContext Generator'. Creating the Controller and the Views Step 6: Add a new controller to the Controllers folder. Give it a meaningful name, such as ReceivePaymentsController. Also, make sure the template selected is 'Controller with empty read/write actions'. Before adding new methods to the Controller, create views for your model. We will add the List, Create, and Delete views. Step 7: Right click on the Views folder and go to Add -> View. Here create a new view for each: List, Create, and Delete templates. Make sure to also associate your Model with the new views. Step 10: Now that the views are ready, go back and edit the RecievePayment controller. Update your code to handle the Index, Create, and Delete methods. Sample Project We are including a sample project that shows how to use the QuickBooks Data Provider in an MVC3 application. You may download the C# project here or download the VB.NET project here. You will also need to install the QuickBooks ADO.NET Data Provider to run the demo. You can download a free trial here. To use this demo, you will also need to modify the connection string in the 'web.config'.

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  • How to manage a growing team?

    - by Andra
    I'm the admin assistant of the CTO and our organization has recently experienced a lot of growth. Within six months, we have merged with another organization and our Dev team has grown from 8 to 16, with another 8 people in QA. What we're dealing with now is a highly technical individual, with little patience, managing a much larger team than he's accustomed to, 40% of which is junior as well as an increase in the number of projects. Needless to say, my boss is being pulled in too many directions at once. How can I help him manage his workload and his team so that the team feels they're getting enough help and support and remain effective? Also, where can I find additional resources on managing a growing team?

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  • How does one handle sensitive data when using Github and Heroku?

    - by Jonas
    I am not yet accustomed with the way Git works (And wonder if someone besides Linus is ;)). If you use Heroku to host you application, you need to have your code checked in a Git repo. If you work on an open-source project, you are more likely going to share this repo on Github or other Git hosts. Some things should not be checked in the public repo; database passwords, API keys, certificates, etc... But these things still need to be part of the Git repo since you use it to push your code to Heroku. How to work with this use case? Note: I know that Heroku or PHPFog can use server variables to circumvent this problem. My question is more about how to "hide" parts of the code.

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  • New vs Clone Git in Eclipse with EGit

    - by Matty F
    I'm not sure I have either my new repo or clone repo workflow, or both, setup correctly. When I create a new project I create a repo on github, can't clone from it as it's empty so I create a new project which goes into my workspace and then the git init runs on the workspace copy. So I end up with everything in workspace\project-name. However, when I clone from github first I need to clone the repo and this goes into my default git directory (C:\git) as git\cloned-project-name, I then need to import this Git repo as a project into my workspace and I end up with workspace\cloned-project-name effectively duplicating the project folder in the git area. I've tried to clone to workspace\cloned-project-name but then it asks to import the git project and if I try to use workspace\cloned-project-name again, it errs. What am I doing wrong? Thanks, Matt.

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  • What are some client-side sitemap generators?

    - by BHare
    Most of the sitemap generators I've found all scan my internal files and base it on that. However using apache and htaccess I have many aliases for things for example: /brand/model/photos/ is empty directory wise, but on the web it relocates it to a zenphoto gallery using htaccess. http://www.xml-sitemaps.com/ does What I need, but I'd like to have more control over it and I need it to be dynamic and run weekly or daily. Allow for specific change frequencies based on the file/directory. I also want to be able to make a "pretty" sitemap html file. Counting the photo gallery I have around 300 links, without the photo gallery more like 100. I have MySQL, PHP 5.3 installed.

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  • Visual Studio 2010: Custom Start Page

    - by Steve Clements
    As Visual Studio 2010 IDE has been mostly written in WPF, extending the start page has become pretty darn easy and I for one find this quite interesting as I always open with the start page and the more customisation I can have the better! There are a few things you will need to install first to get going Visual Studio 2010 SDK Start page project template, which you can either get from the New Project dialog, in the online gallery section in VS or download from here   I was going to write a blog post on how to create a custom start page, but decided that msdn have done such a good job I was pretty much wasting my time, so take a look here, it has in detail everything you need to know to get it done! :) Technorati Tags: Visual Studio 2010,Custom Start Pages

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  • Ubuntu won't run

    - by Cody
    So I just installed it last night, the latest version. I did a fresh install. When I woke this morning I turn on the computer and login. It goes to a black screen with two thick with/multicolored lines towards the bottom and freezes. I then must shut down the tower. I have only been able to run the 'Ubuntu 2D' option. I am new to this all and need some help. Also when I am using terminal it wants me to enter my password, but it says its incorrect. Is there anyway so I don't need to enter my password when I use it and also when I install or remove something? Many thanks would be helpful. What is Ubuntu 2D?

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  • Good architecture for user information on separate databases?

    - by James P. Wright
    I need to write an API to connect to an existing SQL database. The API will be written in ASP.Net MVC3. The slight problem is that with existing users of the system, they may have a username on multiple databases. Each company using the product gets a brand new instance of the database, but over the years (the system has been running for 10 years) there are quite a few users (hundreds) who have multiple usernames across multiple "companies" (things got fragmented obviously and sometimes a single Company has 5 "projects" that each have their own database). Long story short, I need to be able to have a single unified user login that will allow existing users to access their information across all their projects. The only thing I can think is storing a bunch of connection strings, but that feels like a really bad idea. I'll have a new Database that will hold the "unified user" information...can anyone suggest a solid system architecture that can handle a setup like this?

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  • How to Change the Window Border Size in Windows 8

    - by Chris Hoffman
    The window borders on Windows 8’s desktop are fairly thick by default, but they don’t have to be – you can customize the side of the window borders with an easy-to-use application or a quick registry tweak. You can shrink the window borders and make them fairly thin, just as they were on previous versions of Windows. Or you can increase the window border size and make them extremely thick, if you prefer.. HTG Explains: Does Your Android Phone Need an Antivirus? How To Use USB Drives With the Nexus 7 and Other Android Devices Why Does 64-Bit Windows Need a Separate “Program Files (x86)” Folder?

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  • Data management in unexpected places

    - by Ashok_Ora
    Normal 0 false false false EN-US X-NONE X-NONE Data management in unexpected places When you think of network switches, routers, firewall appliances, etc., it may not be obvious that at the heart of these kinds of solutions is an engine that can manage huge amounts of data at very high throughput with low latencies and high availability. Consider a network router that is processing tens (or hundreds) of thousands of network packets per second. So what really happens inside a router? Packets are streaming in at the rate of tens of thousands per second. Each packet has multiple attributes, for example, a destination, associated SLAs etc. For each packet, the router has to determine the address of the next “hop” to the destination; it has to determine how to prioritize this packet. If it’s a high priority packet, then it has to be sent on its way before lower priority packets. As a consequence of prioritizing high priority packets, lower priority data packets may need to be temporarily stored (held back), but addressed fairly. If there are security or privacy requirements associated with the data packet, those have to be enforced. You probably need to keep track of statistics related to the packets processed (someone’s sure to ask). You have to do all this (and more) while preserving high availability i.e. if one of the processors in the router goes down, you have to have a way to continue processing without interruption (the customer won’t be happy with a “choppy” VoIP conversation, right?). And all this has to be achieved without ANY intervention from a human operator – the router is most likely to be in a remote location – it must JUST CONTINUE TO WORK CORRECTLY, even when bad things happen. How is this implemented? As soon as a packet arrives, it is interpreted by the receiving software. The software decodes the packet headers in order to determine the destination, kind of packet (e.g. voice vs. data), SLAs associated with the “owner” of the packet etc. It looks up the internal database of “rules” of how to process this packet and handles the packet accordingly. The software might choose to hold on to the packet safely for some period of time, if it’s a low priority packet. Ah – this sounds very much like a database problem. For each packet, you have to minimally · Look up the most efficient next “hop” towards the destination. The “most efficient” next hop can change, depending on latency, availability etc. · Look up the SLA and determine the priority of this packet (e.g. voice calls get priority over data ftp) · Look up security information associated with this data packet. It may be necessary to retrieve the context for this network packet since a network packet is a small “slice” of a session. The context for the “header” packet needs to be stored in the router, in order to make this work. · If the priority of the packet is low, then “store” the packet temporarily in the router until it is time to forward the packet to the next hop. · Update various statistics about the packet. In most cases, you have to do all this in the context of a single transaction. For example, you want to look up the forwarding address and perform the “send” in a single transaction so that the forwarding address doesn’t change while you’re sending the packet. So, how do you do all this? Berkeley DB is a proven, reliable, high performance, highly available embeddable database, designed for exactly these kinds of usage scenarios. Berkeley DB is a robust, reliable, proven solution that is currently being used in these scenarios. First and foremost, Berkeley DB (or BDB for short) is very very fast. It can process tens or hundreds of thousands of transactions per second. It can be used as a pure in-memory database, or as a disk-persistent database. BDB provides high availability – if one board in the router fails, the system can automatically failover to another board – no manual intervention required. BDB is self-administering – there’s no need for manual intervention in order to maintain a BDB application. No need to send a technician to a remote site in the middle of nowhere on a freezing winter day to perform maintenance operations. BDB is used in over 200 million deployments worldwide for the past two decades for mission-critical applications such as the one described here. You have a choice of spending valuable resources to implement similar functionality, or, you could simply embed BDB in your application and off you go! I know what I’d do – choose BDB, so I can focus on my business problem. What will you do? /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

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  • Ranking - Part II

    - by PointsToShare
    © 2011 By: Dov Trietsch. All rights reserved   Ranking Part II In my introduction to ranking I also introduced the Ranking Game. This is actually a much more sophisticated program than the one we need to simply rate an item, but it introduced you to the sophisticated results that you may achieve by a bit of code and accompanying CSS. In this installment, I am going to handle simple rating with 5 stars. The extra sophistication will come in the form of creating new elements in run time. Why do I need this? I like to be able to extend the SharePoint New and Update forms and put the starts in them simply by using the code shown here. We do not even need to go into SPD. We may achieve this simply by adding a content editor web part; more about this in the next installment. I have created a new page – Rank the Author – in which you may praise me in 5 different ways, but not immediately. The ranking mechanism – the 5 stars – has to be created first. To achieve that, click the “Add Element” button on the screen and then proceed in giving me the appropriate number of stars. Now view the source and see how this extra 5 start element was added. Also see how the ranking is achieved. This, obviously, is not any different in principle than what we did in the Ranking game. We create some sophisticated HTML, Add some style and create the element by: var divString = "<div id="rateMe" title="Rate Me...">    <a onclick="rateIt(this)" id="_1" title="ehh..." onmouseover="rating(this)" onmouseout="off(this)"></a>    <a onclick="rateIt(this)" id="_2" title="So So" onmouseover="rating(this)" onmouseout="off(this)"></a>    <a onclick="rateIt(this)" id="_3" title="Passable" onmouseover="rating(this)" onmouseout="off(this)"></a>    <a onclick="rateIt(this)" id="_4" title="Not too Bad" onmouseover="rating(this)" onmouseout="off(this)"></a>    <a onclick="rateIt(this)" id="_5" title="Not Bad" onmouseover="rating(this)" onmouseout="off(this)"></a></div>";m = document.createElement("p");m.innerHTML = divString;m.className = "blah";function AddElement(){    y = document.getElementById("Rest");    y.parentNode.insertBefore(m, y);} When you look into the full code, you’ll notice that I have added an empty <div id=”Rest”> into the form. A div element, like p, creates a line break, but the main purpose here was to mark the place above which I wanted to add the stars. Now you may hover over the stars, see how they behave and click on one of them to see that the program can react to your selection. That’s all folks!

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