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• VS2010 Launch Presentations

  Last week I was in Vegas to present at the DevConnections / VS2010 Launch event.  The show was well-attended and everybody I spoke to agreed it was educational and enjoyable.  My three talks were all on Wednesday, 14 April 2010, including one at 8am for which I was impressed to see a large turnout in attendance.   Pragmatic ASP.NET Tips, Tricks, and Tools My first session was on tips, tricks, and tools for ASP.NET developers.  This is a talk Ive given in past years, but which I refine every time.  I usually like to have a full session to devote to tools, and a separate talk just for Tips and Tricks, but for this show I was only given the one 75-minute slot, so I had to cut some materials to make things fit.  The talk went well, all the demos work, and the attendees seemed to enjoy it, and I like giving it, so hopefully I can continue to present on this topic in future DevConnections shows. Download the ASP.NET Tips, Tricks, and Tools slides and demos.   Whats New in ASP.NET MVC 2 My second talk of the day followed immediately after the Tips and Tricks talk, and was a brand new talk for me.  I have to throw out a thank-you to Phil for letting me see his MIX slide deck before he gave his talk, as that was a big help.  The official whats new document online is also worth checking out if youre interested in this subject.  Download the Whats New in ASP.NET MVC 2 slides and demos.   SOLIDify Your ASP.NET MVC 2 Application Just because youre using a ASP.NET MVC doesnt mean your code cant still end up being a big ball of mud.  This session describes a number of principles of software design that can help ensure applications remain loosely-coupled and malleable even as they age and increase in features and complexity.  This was my last talk of the day and did have one minor demo failure involving a database constraint.  Ive given this talk many times before, and in this case I had to fit it into a 60-minute timeslot, so Im not sure I had quite enough time to drive home all of the concepts to everyone in the audience.  That said, I did hear a number of positive comments on how the talk went, so thats encouraging. Download the SOLIDify Your ASP.NET MVC 2 Application slides and demos.   In my sessions, I promised to have these posted by the end of the weekend theyre going up at 10pm Sunday night (my time) 2 hours to spare!  Enjoy! Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Google I/O 2012 - Introducing the Google Drive SDK

  Google I/O 2012 - Introducing the Google Drive SDK In this talk, we will introduce a number of major new features and platforms to the Google Drive SDK. We will discuss what we feel is a revolution in the way developers write collaborative applications. We will also announce a new API to make managing files in Google Drive even easier for developers, replacing some legacy APIs in the process. For all I/O 2012 sessions, go to developers.google.com From: GoogleDevelopers Views: 2447 16 ratings Time: 46:28 More in Science & Technology

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• New Features In Photoshop CS4

  Adobe Photoshop is the most popular image editing software in the world. It';s used by a number of professionals in the photo, magazine, and film industries, among others. When a new update comes, man... [Author: Mandi Pralle - Computers and Internet - March 29, 2010]

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• Get Info From Database, or Build Inferred Info?

  - by Zaemz

  Does it make more sense to store and retrieve properties or information directly related to an item in a database, or, say in such a case that a product's ID could describe information about it, should the information be gathered from that? Example: Item SKU -- 4HBU12 4 - is the number of motors H - the voltage B - the color, blue U - the model 12 - the length Should I store those individual attributes as well as the SKU, or should I store only the SKU and build the attributes from it?

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• Google Analytics - comparing metrics for different cities approach

  - by crmpicco

  I receive traffic from a number of different cities across the world, these being: Washington, Bratislava and Belfast. In Google Analytics, I would like to be able to compare a variety of metrics (side by side), however i'm not sure how to go about this in the best way. Am I looking at creating 3 advanced segments, 3 profiles or should I be doing it in one custom report? Or is this even possible in Google Analytics version 5?

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• glGetActiveAttrib on Android NDK

  - by user408952

  In my code-base I need to link the vertex declarations from a mesh to the attributes of a shader. To do this I retrieve all the attribute names after linking the shader. I use the following code (with some added debug info since it's not really working): int shaders[] = { m_ps, m_vs }; if(linkProgram(shaders, 2)) { ASSERT(glIsProgram(m_program) == GL_TRUE, "program is invalid"); int attrCount = 0; GL_CHECKED(glGetProgramiv(m_program, GL_ACTIVE_ATTRIBUTES, &attrCount)); int maxAttrLength = 0; GL_CHECKED(glGetProgramiv(m_program, GL_ACTIVE_ATTRIBUTE_MAX_LENGTH, &maxAttrLength)); LOG_INFO("shader", "got %d attributes for '%s' (%d) (maxlen: %d)", attrCount, name, m_program, maxAttrLength); m_attrs.reserve(attrCount); GLsizei attrLength = -1; GLint attrSize = -1; GLenum attrType = 0; char tmp[256]; for(int i = 0; i < attrCount; i++) { tmp[0] = 0; GL_CHECKED(glGetActiveAttrib(m_program, GLuint(i), sizeof(tmp), &attrLength, &attrSize, &attrType, tmp)); LOG_INFO("shader", "%d: %d %d '%s'", i, attrLength, attrSize, tmp); m_attrs.append(String(tmp, attrLength)); } } GL_CHECKED is a macro that calls the function and calls glGetError() to see if something went wrong. This code works perfectly on Windows 7 using ANGLE and gives this this output: info:shader: got 2 attributes for 'static/simplecolor.glsl' (3) (maxlen: 11) info:shader: 0: 7 1 'a_Color' info:shader: 1: 10 1 'a_Position' But on my Nexus 7 (1st gen) I get the following (the errors are the output from the GL_CHECKED macro): I/testgame:shader(30865): got 2 attributes for 'static/simplecolor.glsl' (3) (maxlen: 11) E/testgame:gl(30865): 'glGetActiveAttrib(m_program, GLuint(i), sizeof(tmp), &attrLength, &attrSize, &attrType, tmp)' failed: INVALID_VALUE [jni/src/../../../../src/Game/Asset/ShaderAsset.cpp:50] I/testgame:shader(30865): 0: -1 -1 '' E/testgame:gl(30865): 'glGetActiveAttrib(m_program, GLuint(i), sizeof(tmp), &attrLength, &attrSize, &attrType, tmp)' failed: INVALID_VALUE [jni/src/../../../../src/Game/Asset/ShaderAsset.cpp:50] I/testgame:shader(30865): 1: -1 -1 '' I.e. the call to glGetActiveAttrib gives me an INVALID_VALUE. The opengl docs says this about the possible errors: GL_INVALID_VALUE is generated if program is not a value generated by OpenGL. This is not the case, I added an ASSERT to make sure glIsProgram(m_program) == GL_TRUE, and it doesn't trigger. GL_INVALID_OPERATION is generated if program is not a program object. Different error. GL_INVALID_VALUE is generated if index is greater than or equal to the number of active attribute variables in program. i is 0 and 1, and the number of active attribute variables are 2, so this isn't the case. GL_INVALID_VALUE is generated if bufSize is less than 0. Well, it's not zero, it's 256. Does anyone have an idea what's causing this? Am I just lucky that it works in ANGLE, or is the nvidia tegra driver wrong?

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• Simple Web Marketing, Search Engine Optimization Strategies For an Online Small Business

  There are a number of simple web marketing, search engine optimization strategies you should keep in mind when you are dealing with an online small business. Regardless of whether you are an offline small business entrepreneur with a company website or, exclusively, an online small-business entrepreneur, these are the simple web marketing, search engine optimization guidelines you ought to keep in mind.

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• Oracle Policy Automation YouTube Videos

  - by Wes Curtis

  The Oracle PSRM integration with Oracle Policy Automation provides a great option for implementing business rules as Microsoft Word and Excel documents. The following YouTube site includes a large number of videos on various OPA topics including feature introductions, tutorials and overview presentations. Be sure to check these out if you would like to learn more about OPA and it's capabilities. http://www.youtube.com/user/OraclePAVideos

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• SEO Mistakes

  Search engines are an important part of advertising, and because it is so important, a number of false rumors, prejudices and obsolete secrecy are placed on them. Perhaps the most common is the good times text invisible art.

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• OEL5.5 released

  - by wim.coekaerts

  OEL 5.5 got pushed to ULN last night. we are creating the 5.5 base channel right now - for those that want the convenience of register to a specific update channel only. This is something we have done since the beginning (on ULN). The ISO images will appear on e-delivery in a number of days and for those customers that need urgent ISO access they can file a support SR.

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• External hard drive not recognized

  - by sr71

  Installed Ubuntu 10.10 on a hard drive by itself (no windows). All updates are up to date. Everything`works fine except when I plug in a 320 gig Toshiba external hard drive....it is not recognized. When I plug in an 8 gig flash drive it is recognized no problem. What do I mean by "not recognized"? I mean: how do you know it was not recognized. You can check the command "cat /proc/partitions" in a terminal with and without the hdd attached. If you see some difference, it's ok. If the difference is something like "sda1" (sd+letter+number) then you have partition on it, maybe it can't be handled in Ubuntu (no filesystem on it or so). If there is only "sda" in the difference for example (sd+letter, but no number after it) then the drive itself is detected, just no partition is created on it. Also you can check out the messages of the kernel, with the "dmesg" command in the terminal. If there is no disk/partition/anything in /proc/partitions, there can be an USB level problem, you can issue command "lsusb" as it was suggested before my answer. It's really matter of what do you mean about "not recognized". @Marco Ceppi @Oli @Pitto By "not recognized" I meant that when I plug in a 8 gig flash drive an icon immediately appears on the desktop imdicating that there is a flash drive plugged in and I can click on it and view the files on the flash drive. It also shows up on the "Nautilus" default file manager. When I plug in the 320 gig Toshiba external hard drive, I get no indication on the desktop or the file manager (thus "not recogized"). When I run the command cat/proc/partitions/ I get an error message Could not open location 'file:///home/bob/cat/proc/partitions' with or without the external hard drive installed. With the dmeg command I get about 10 pages of info with no mention of disk/partition/anything in /proc/partitions. When I run lsusb command I get the following: bob@bob-desktop:~$ lsusb Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 003: ID 04b3:3003 IBM Corp. Rapid Access III Keyboard Bus 003 Device 002: ID 04b3:3004 IBM Corp. Media Access Pro Keyboard Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

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• Free eBooks - SQL Server and other Microsoft Technologies

  - by Greg Low

  Great to see the advice from Gail Erickson about the release of a number of SQL Server related eBooks on the new Microsoft eBook Gallery site. It's good to see this sort of content moving over to eBook formats.The e-books that are currently available include: SQL Server 2012 Transact-SQL DML Reference Master Data Services Capacity Guidelines Microsoft SQL Server AlwaysOn Solutions Guide for High Availability and Disaster Recovery QuickStart: Learn DAX Basics in 30 Minutes Microsoft SQL Server Analysis Services Multidimensional Performance and Operations Guide You'll find details of them here: http://social.technet.microsoft.com/wiki/contents/articles/11608.e-book-gallery-for-microsoft-technologies.aspx

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• Set and Verify the Retention Value for Change Data Capture

  - by AllenMWhite

  Last summer I set up Change Data Capture for a client to track changes to their application database to apply those changes to their data warehouse. The client had some issues a short while back and felt they needed to increase the retention period from the default 3 days to 5 days. I ran this query to make that change: sp_cdc_change_job @job_type='cleanup', @retention=7200 The value 7200 represents the number of minutes in a period of 5 days. All was well, but they recently asked how they can verify...(read more)

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• Built-In SQL Server Agent Performance Reports in SQL Server 2005

  SQL Server 2005 includes a number of built-in reports to assist you in troubleshooting and measuring performance. In this tip I will cover the Built in SQL Server Performance Reports related to SQL Server Agent within SQL Server 2005.

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• Drawing lots of tiles with OpenGL, the modern way

  - by Nic

  I'm working on a small tile/sprite-based PC game with a team of people, and we're running into performance issues. The last time I used OpenGL was around 2004, so I've been teaching myself how to use the core profile, and I'm finding myself a little confused. I need to draw in the neighborhood of 250-750 48x48 tiles to the screen every frame, as well as maybe around 50 sprites. The tiles only change when a new level is loaded, and the sprites are changing all the time. Some of the tiles are made up of four 24x24 pieces, and most (but not all) of the sprites are the same size as the tiles. A lot of the tiles and sprites use alpha blending. Right now I'm doing all of this in immediate mode, which I know is a bad idea. All the same, when one of our team members tries to run it, he gets very bad frame rates (~20-30 fps), and it's much worse when there are more tiles, especially when a lot of those tiles are the kind that are cut into pieces. This all makes me think that the problem is the number of draw calls being made. I've thought of a few possible solutions to this, but I wanted to run them by some people who know what they're talking about so I don't waste my time on something stupid: TILES: When a level is loaded, draw all the tiles once into a frame buffer attached to a big honking texture, and just draw a big rectangle with that texture on it every frame. Put all the tiles into a static vertex buffer when the level is loaded, and draw them that way. I don't know if there's a way to draw objects with different textures with a single call to glDrawElements, or if this is even something I'd want to do. Maybe just put all the tiles into a big giant texture and use funny texture coordinates in the VBO? SPRITES: Draw each sprite with a separate call to glDrawElements. Use a dynamic VBO somehow. Same texture question as number 2 above. Point sprites? This is probably silly. Are any of these ideas sensible? Is there a good implementation somewhere I could look over?

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• Using jQuery to customize the styles in table cells

  - by Chris Hammond

  Originally posted on ChrisHammond.com I was trying to do some work with the Form and List module in DotNetNuke today and I needed to apply some custom styles to the LIST view of a module, without going in and creating a full XSL template for the module to use, I wanted to style the default table based grid view. In order to customize this view though I needed to do some custom jQuery that runs after the table is loaded, the jQuery then goes through and looks for columns, and based on the number of...(read more)

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• New free DotNetNuke 7.0 Skin

  - by Chris Hammond

  With the pending release of DotNetNuke 7, scheduled for this week, I updated my free DotNetNuke (DNN) skin , MultiFunction v1.3 . This latest release requires DotNetNuke 7, it shouldn’t install on an earlier version of DNN. This release updates a number of the CSS classes for DNN 7 specific styles and objects. Overall the design of the skin doesn’t really change much, just cleans up CSS mainly for this release. I also updated to the 3.0 version of the Orangebox jQuery plugin, you can find the code...(read more)

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• Weeding out real agile from buzzword agile in an interview

  - by indyK1ng

  I've been interviewing for co-ops (paid internships) lately and a large number of the companies I've been interviewing with have been saying they use Scrum or some other agile methodology (scrum being the most popular). I know that there are real agile shops and there are places which say they use an agile methodology but are really doing something else and using agile as a buzzword. My question is, what are some questions I can ask in an interview which would separate these shops out?

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• Correct way to handle path-finding collision matrix

  - by Xander Lamkins

  Here is an example of me utilizing path finding. The red grid represents the grid utilized by my A* library to locate a distance. This picture is only an example, currently it is all calculated on the 1x1 pixel level (pretty darn laggy). I want to make it so that the farther I click, the less accurate it will be (split the map into larger grid pieces). Edit: as mentioned by Eric, this is not a required game mechanic. I am perfectly fine with any method that allows me to make this accurate while still fast. This isn't the really the topic of this question though. The problem I have is, my current library uses a two dimensional grid of integers. The higher the number in a cell, the more resistance for that grid tile. Currently I'm setting all unwalkable spots to Integer Max. Here is an example of what I want: I'm just not sure how I should set up the arrays of integers of the grid. Every time an element is added/removed to/from the game, it's collision details are updated in the table. Here is a picture of what the map looks like on my collision layer: I probably shouldn't be creating new arrays every time I have to do a path find because my game needs to support tons of PF at the same time. Should I have multiple arrays that are all updated when the dynamic elements are updated (a building is built/a building is destroyed). The problem I see with this is that it will probably make the creation and destruction of buildings a little more laggy than I would want because it would be setting the collision grid for each built in accuracy level. I would also have to add more/remove some arrays if I ever in the future changed the map size. Should I generate the new array based on an accuracy value every time I need to PF? The problem I see with this is that it will probably make any form of PF just as laggy because it will have to search through a MapWidth x MapHeight number of cells to shrink it all down. Or is there a better way? I'm certainly not the best at optimizing really anything. I've just started dealing with XNA so I'm not used to having optimization code really doing much of an affect until now... :( If you need code examples, please ask. I'll add it as an edit. EDIT: While this doesn't directly relate to the question, I figure the more information I provide, the better. To keep your units from moving as accurately to the players desired position, I've decided that once the unit PFs over to the less accurate grid piece, it will then PF on a more accurate level to the exact position requested.

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• Playing with F#

  - by mroberts

  Project Euler is a awesome site.   When working with a new language it can be tricky to find problems that need solving, that are more complex than "Hello World" and simpler than a full blown application. Project Euler gives use just that, cool and thought provoking problems that usually don't take days to solve.  I've solved a number of questions with C# and some with Java.  BTW, I used Java because it had BigInteger support before .Net. A couple weeks ago, back when winter had a firm grip on Columbus, OH, I began playing (researching) with F#.  I began with Problem #1 from Project Euler.  I started by looking at my solution in C#. Here is my solution in C#. 1: using System; 2: using System.Collections.Generic; 3:   4: namespace Problem001 5: { 6: class Program 7: { 8: static void Main(string[] args) 9: { 10: List<int> values = new List<int>(); 11:   12: for (int i = 1; i < 1000; i++) 13: { 14: if (i % 3 == 0 || i % 5 == 0) 15: values.Add(i); 16: } 17: int total = 0; 18:   19: values.ForEach(v => total += v); 20:   21: Console.WriteLine(total); 22: Console.ReadKey(); 23: } 24: } 25: }   Now, after much tweaking and learning, here is my solution in F#.   1: open System 2:   3: let calc n = 4: [1..n] 5: |> List.map (fun x -> if (x % 3 = 0 || x % 5 = 0) then x else 0) 6: |> List.sum 7:   8: let main() = 9: calc 999 10: |> printfn "result = %d" 11: Console.ReadKey(true) |> ignore 12:   13: main() Just this little example highlights some cool things about F#. Type inference. F# infers the type of a value.  In the C# code above we declare a number of variables, the list, and a couple ints.  F# does not require this, it infers the calc (a function) accepts a int and returns a int. Great built in functionality for Lists.  List.map for example. BTW, I don’t think I’m spilling the beans by giving away the code for Problem 1.  It by far is the easiest question, IMHO, solved by 92,000+ people. Next I’ll look into writing a class library with F#.

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• Reduce weight in healthy way - Day 2

  - by krnites

  My second day of reducing weight and it seems most of the blog are correct in saying that you can reduce weight if your calorie consumption is less than what you burn. In one day I have lost 1 lbs without doing anything. My current weight is 177.4 lbs. Yesterday I ate small portion of dinner that I used to eat that also around 7 PM. Normally I eat my dinner around 10 PM and withing 2 hour of eating I go for sleep, but yesterday I ate around 7 PM and went for sleep only after 12.On my second day I have eaten noodles and 3 eggs in breakfast and sesame chicken ( I love it) and fried rice in lunch, I still have not gone for running but had plan to go for running and then swimming. I hope it will at least burn the calories that I had taken. On some site it was written that a normal men body needs around 2000 Calorie a day. So if I am eating less than 2000 calorie ( noodles + 3 eggs = 400+200, rice + sesame chicken = 1300, total = 1900) and burning around 300 calorie, my total calorie intake will be 1600 which is less than what my body needs. So most probably by tomorrow I should come under 176 lb bracket.Apart from counting the calorie that I am taking in everyday and approx number of calorie that I am burning everyday, I had also starting tracking my physical activities on my mobile. I have got a beautiful Samsung Focus S Windows 7.5 mobile. And after browsing through the market I have downloaded couple of health Apps.1. 6 Week training - this has set of exercise and lets you choose the number of sets you want to do for all exercise. Its focus on your core muscles.2. Fast food Calories - This apps has all the fast food chain listed and give the calorie count of each of the food item available on there menu. Like for Burger King's French Fries Large (Salted) contains 500 Calorie.3. Gym Pocket Guide - Contains instructions for different kind of exercise and tells a right way of doing them.4.  RunSat - kind of GPS based application. Its mark the distance you have run, shows the path you have taken on a map, total calorie burnt, laps completed. I love this apps.5. Stop Watch I also have noticed that If I am running in GYM and have television in front of me where a movie or serial is going on which I like,  I normally didn't notice the time. Most of the time running on treadmill is very boring, but if some music video is playing or some kind of sitcom is going, I can run for  a hour or half.So on day 2 I have lost 1 lbs and had learnt that calorie intake should be less then calorie burnt for a given day.

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• Spatial data from shapefiles (for T-SQL Tuesday #006)

  - by Rob Farley

  I’m giving a presentation on May 12th at the Adelaide .Net User Group, around the topic of spatial data, and in particular, the visualization of said data. Given that it’s about one the larger types, this post should also count towards Michael Coles’ T-SQL Tuesday on BLOB data . I wrote recently about my experience with exploded data , but what I didn’t go on to talk about was how using a shapefile like this would translate into a scenario with a much larger number of shapes, such as all the postcode...(read more)

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• Grep through subdirectories

  - by Kathryn

  Add a string to a text file from terminal I've been looking at this thread. The solution (number 2, with ls | grep) works perfectly for files called .txt in the current directory. How about if I wanted to search through a directory and the subdirectories therein? For example, I have to search through a directory that has many subdirectories, and they have many subdirectories etc. I'm new to Linux sorry, so I'm not sure if this is the right place

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• Computer Networks UNISA - Chap 10 &ndash; In Depth TCP/IP Networking

  - by MarkPearl

  After reading this section you should be able to Understand methods of network design unique to TCP/IP networks, including subnetting, CIDR, and address translation Explain the differences between public and private TCP/IP networks Describe protocols used between mail clients and mail servers, including SMTP, POP3, and IMAP4 Employ multiple TCP/IP utilities for network discovery and troubleshooting Designing TCP/IP-Based Networks The following sections explain how network and host information in an IPv4 address can be manipulated to subdivide networks into smaller segments. Subnetting Subnetting separates a network into multiple logically defined segments, or subnets. Networks are commonly subnetted according to geographic locations, departmental boundaries, or technology types. A network administrator might separate traffic to accomplish the following… Enhance security Improve performance Simplify troubleshooting The challenges of Classful Addressing in IPv4 (No subnetting) The simplest type of IPv4 is known as classful addressing (which was the Class A, Class B & Class C network addresses). Classful addressing has the following limitations. Restriction in the number of usable IPv4 addresses (class C would be limited to 254 addresses) Difficult to separate traffic from various parts of a network Because of the above reasons, subnetting was introduced. IPv4 Subnet Masks Subnetting depends on the use of subnet masks to identify how a network is subdivided. A subnet mask indicates where network information is located in an IPv4 address. The 1 in a subnet mask indicates that corresponding bits in the IPv4 address contain network information (likewise 0 indicates the opposite) Each network class is associated with a default subnet mask… Class A = 255.0.0.0 Class B = 255.255.0.0 Class C = 255.255.255.0 An example of calculating  the network ID for a particular device with a subnet mask is shown below.. IP Address = 199.34.89.127 Subnet Mask = 255.255.255.0 Resultant Network ID = 199.34.89.0 IPv4 Subnetting Techniques Subnetting breaks the rules of classful IPv4 addressing. Read page 490 for a detailed explanation Calculating IPv4 Subnets Read page 491 – 494 for an explanation Important… Subnetting only applies to the devices internal to your network. Everything external looks at the class of the IP address instead of the subnet network ID. This way, traffic directed to your network externally still knows where to go, and once it has entered your internal network it can then be prioritized and segmented. CIDR (classless Interdomain Routing) CIDR is also known as classless routing or supernetting. In CIDR conventional network class distinctions do not exist, a subnet boundary can move to the left, therefore generating more usable IP addresses on your network. A subnet created by moving the subnet boundary to the left is known as a supernet. With CIDR also came new shorthand for denoting the position of subnet boundaries known as CIDR notation or slash notation. CIDR notation takes the form of the network ID followed by a forward slash (/) followed by the number of bits that are used for the extended network prefix. To take advantage of classless routing, your networks routers must be able to interpret IP addresses that don;t adhere to conventional network class parameters. Routers that rely on older routing protocols (i.e. RIP) are not capable of interpreting classless IP addresses. Internet Gateways Gateways are a combination of software and hardware that enable two different network segments to exchange data. A gateway facilitates communication between different networks or subnets. Because on device cannot send data directly to a device on another subnet, a gateway must intercede and hand off the information. Every device on a TCP/IP based network has a default gateway (a gateway that first interprets its outbound requests to other subnets, and then interprets its inbound requests from other subnets). The internet contains a vast number of routers and gateways. If each gateway had to track addressing information for every other gateway on the Internet, it would be overtaxed. Instead, each handles only a relatively small amount of addressing information, which it uses to forward data to another gateway that knows more about the data’s destination. The gateways that make up the internet backbone are called core gateways. Address Translation An organizations default gateway can also be used to “hide” the organizations internal IP addresses and keep them from being recognized on a public network. A public network is one that any user may access with little or no restrictions. On private networks, hiding IP addresses allows network managers more flexibility in assigning addresses. Clients behind a gateway may use any IP addressing scheme, regardless of whether it is recognized as legitimate by the Internet authorities but as soon as those devices need to go on the internet, they must have legitimate IP addresses to exchange data. When a clients transmission reaches the default gateway, the gateway opens the IP datagram and replaces the client’s private IP address with an Internet recognized IP address. This process is known as NAT (Network Address Translation). TCP/IP Mail Services All Internet mail services rely on the same principles of mail delivery, storage, and pickup, though they may use different types of software to accomplish these functions. Email servers and clients communicate through special TCP/IP application layer protocols. These protocols, all of which operate on a variety of operating systems are discussed below… SMTP (Simple Mail transfer Protocol) The protocol responsible for moving messages from one mail server to another over TCP/IP based networks. SMTP belongs to the application layer of the ODI model and relies on TCP as its transport protocol. Operates from port 25 on the SMTP server Simple sub-protocol, incapable of doing anything more than transporting mail or holding it in a queue MIME (Multipurpose Internet Mail Extensions) The standard message format specified by SMTP allows for lines that contain no more than 1000 ascii characters meaning if you relied solely on SMTP you would have very short messages and nothing like pictures included in an email. MIME us a standard for encoding and interpreting binary files, images, video, and non-ascii character sets within an email message. MIME identifies each element of a mail message according to content type. MIME does not replace SMTP but works in conjunction with it. Most modern email clients and servers support MIME POP (Post Office Protocol) POP is an application layer protocol used to retrieve messages from a mail server POP3 relies on TCP and operates over port 110 With POP3 mail is delivered and stored on a mail server until it is downloaded by a user Disadvantage of POP3 is that it typically does not allow users to save their messages on the server because of this IMAP is sometimes used IMAP (Internet Message Access Protocol) IMAP is a retrieval protocol that was developed as a more sophisticated alternative to POP3 The single biggest advantage IMAP4 has over POP3 is that users can store messages on the mail server, rather than having to continually download them Users can retrieve all or only a portion of any mail message Users can review their messages and delete them while the messages remain on the server Users can create sophisticated methods of organizing messages on the server Users can share a mailbox in a central location Disadvantages of IMAP are typically related to the fact that it requires more storage space on the server. Additional TCP/IP Utilities Nearly all TCP/IP utilities can be accessed from the command prompt on any type of server or client running TCP/IP. The syntaxt may differ depending on the OS of the client. Below is a list of additional TCP/IP utilities – research their use on your own! Ipconfig (Windows) & Ifconfig (Linux) Netstat Nbtstat Hostname, Host & Nslookup Dig (Linux) Whois (Linux) Traceroute (Tracert) Mtr (my traceroute) Route

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• Function Folding in #PowerQuery

  - by Darren Gosbell

  Originally posted on: http://geekswithblogs.net/darrengosbell/archive/2014/05/16/function-folding-in-powerquery.aspxLooking at a typical Power Query query you will noticed that it's made up of a number of small steps. As an example take a look at the query I did in my previous post about joining a fact table to a slowly changing dimension. It was roughly built up of the following steps: Get all records from the fact table Get all records from the dimension table do an outer join between these two tables on the business key (resulting in an increase in the row count as there are multiple records in the dimension table for each business key) Filter out the excess rows introduced in step 3 remove extra columns that are not required in the final result set. If Power Query was to execute a query like this literally, following the same steps in the same order it would not be overly efficient. Particularly if your two source tables were quite large. However Power Query has a feature called function folding where it can take a number of these small steps and push them down to the data source. The degree of function folding that can be performed depends on the data source, As you might expect, relational data sources like SQL Server, Oracle and Teradata support folding, but so do some of the other sources like OData, Exchange and Active Directory. To explore how this works I took the data from my previous post and loaded it into a SQL database. Then I converted my Power Query expression to source it's data from that database. Below is the resulting Power Query which I edited by hand so that the whole thing can be shown in a single expression: let     SqlSource = Sql.Database("localhost", "PowerQueryTest"),     BU = SqlSource{[Schema="dbo",Item="BU"]}[Data],     Fact = SqlSource{[Schema="dbo",Item="fact"]}[Data],     Source = Table.NestedJoin(Fact,{"BU_Code"},BU,{"BU_Code"},"NewColumn"),     LeftJoin = Table.ExpandTableColumn(Source, "NewColumn"                                   , {"BU_Key", "StartDate", "EndDate"}                                   , {"BU_Key", "StartDate", "EndDate"}),     BetweenFilter = Table.SelectRows(LeftJoin, each (([Date] >= [StartDate]) and ([Date] <= [EndDate])) ),     RemovedColumns = Table.RemoveColumns(BetweenFilter,{"StartDate", "EndDate"}) in     RemovedColumns If the above query was run step by step in a literal fashion you would expect it to run two queries against the SQL database doing "SELECT * …" from both tables. However a profiler trace shows just the following single SQL query: select [_].[BU_Code],     [_].[Date],     [_].[Amount],     [_].[BU_Key] from (     select [$Outer].[BU_Code],         [$Outer].[Date],         [$Outer].[Amount],         [$Inner].[BU_Key],         [$Inner].[StartDate],         [$Inner].[EndDate]     from [dbo].[fact] as [$Outer]     left outer join     (         select [_].[BU_Key] as [BU_Key],             [_].[BU_Code] as [BU_Code2],             [_].[BU_Name] as [BU_Name],             [_].[StartDate] as [StartDate],             [_].[EndDate] as [EndDate]         from [dbo].[BU] as [_]     ) as [$Inner] on ([$Outer].[BU_Code] = [$Inner].[BU_Code2] or [$Outer].[BU_Code] is null and [$Inner].[BU_Code2] is null) ) as [_] where [_].[Date] >= [_].[StartDate] and [_].[Date] <= [_].[EndDate] The resulting query is a little strange, you can probably tell that it was generated programmatically. But if you look closely you'll notice that every single part of the Power Query formula has been pushed down to SQL Server. Power Query itself ends up just constructing the query and passing the results back to Excel, it does not do any of the data transformation steps itself. So now you can feel a bit more comfortable showing Power Query to your less technical Colleagues knowing that the tool will do it's best fold all the  small steps in Power Query down the most efficient query that it can against the source systems.

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