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  • Essbase 11.1.2 - AgtSvrConnections Essbase Configuration Setting

    - by Ann Donahue
    AgtSvrConnections is a documented Essbase configuration setting used in conjunction with the AgentThreads and ServerThreads settings. Basically, when a user logs into Essbase, the AgentThreads connects to the ESSBASE process then the AgtSvrConnections will connect the ESSBASE process to the ESSSVR application process which then the ServerThreads are used for end user activities. In Essbase 11.1.2, the default value of the AgtSvrConnections setting was changed to 5. In previous Essbase releases, the AgtSvrConnections setting default value is 1. It is recommended that tuning the AgtSvrConnections settings be done incrementally by 1 or 2 maximum and based on the number of concurrent Set Active/Clear Active calls. In the Essbase DBA Guide and Technical Reference, the maximum setting recommended is to not exceed what is set for AgentThreads, however, we have found that most customers do not need to exceed a setting of 10. In general, it is ok to set AgtSvrConnections close to the AgentThreads setting, however, there have been customers that needed an AgentThread setting greater than 10 and we have found that the AgtSvrConnections setting higher than 5-10 could have a negative impact on Essbase due to too many TCP ports used unnecessarily. As with all Essbase.cfg settings, it is best to set values to what is needed based on process load and not arbitrarily set to high values. In order to monitor and tune the AgtSvrConnections setting, monitor the application log for logins and Set Active/Clear Active messages. If there are a lot of logins and Set Active/Clear Active messages happening in a short period of time making it appear that the login is taking longer, incrementally increase the AgtSvrConnections setting by 1 or 2, which can then help with login speed. The login performance tolerance is different from one customer environment to another since there are other factors that can impact this performance i.e. network latency. What is happening in Essbase when a user logs in: ESSBASE issues a Set Active to the ESSSVR process. Each application has its own ESSSVR process. Set Active then calls MultipleAsyncLogout and waits on the pipe connection. MultipleAsyncLogout goes back to ESSBASE. ESSBASE then needs to send the logout back to the ESSSVR process. When the AgtSvrConnections setting needs to be increased from the default of 5, it is because Essbase cannot find a connection since the previous connections are used by ESSBASE-ESSSVR. In this example, we may want to increase AgtSvrConnections from 5 to 7 to improve the login performance. Again, it is best to set Essbase settings to what is needed based on process load and not arbitrarily set to high values. In general, stress or performance testing environments using automated tools may need higher than normal settings. This is because automated processes run at high speeds for logging in and logging out. Typically, in a real life production environment, the settings are much closer to default values.

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  • Strange things appear on running the program

    - by FILIaS
    Hey! I'm fixing a program but I'm facing a problem and I cant really realize what's the wrong on the code. I would appreciate any help. I didnt post all the code...but i think with this part you can get an idea of it. With the following function enter() I wanna add user commands' datas to a list. eg. user give the command: "enter james bond 007 gun" 'james' is supposed to be the name, 'bond' the surname, 007 the amount and the rest is the description. I use strtok in order to 'cut' the command,then i put each name on a temp array. Then i call InsertSort in order to put the datas on a linked list but in alphabetical order depending on the surname that users give. I wanna keep the list on order and put each time the elements on the right position. /* struct for all the datas that user enters on file*/ typedef struct catalog { char short_name[50]; char surname[50]; signed int amount; char description[1000]; struct catalog *next; }catalog,*catalogPointer; catalogPointer current; catalogPointer head = NULL; void enter(void)//user command: enter <name> <surname> <amount> <description> { int n,j=2,k=0; char temp[1500]; char command[1500]; while (command[j]!=' ' && command[j]!='\0') { temp[k]=command[j]; j++; k++; } temp[k]='\0'; char *curToken = strtok(temp," "); printf("temp is:%s \n",temp); char short_name[50],surname[50],description[1000]; signed int amount; //short_name=(char *)malloc(sizeof (char *)); //surname=(char *)malloc(sizeof (char *)); //description=(char *)malloc(sizeof (char *)); //amount=(int *)malloc(sizeof (int *)); printf("\nWhat you entered for saving:\n"); for (n = 0; curToken !='\0'; ++n) { if (curToken) { strncpy(short_name, curToken, sizeof (char *)); / } printf("Short Name: %s \n",short_name); curToken = strtok(NULL," "); if (curToken) strncpy(surname, curToken, sizeof (char *)); / printf("SurName: %s \n",surname); curToken = strtok(NULL," "); if (curToken) { char *chk; amount = (int) strtol(curToken, &chk, 10); if (!isspace(*chk) && *chk != 0) fprintf(stderr,"Warning: expected integer value for amount, received %s instead\n",curToken); } printf("Amount: %d \n",amount); curToken = strtok(NULL,"\0"); if (curToken) { strncpy(description, curToken, sizeof (char *)); } printf("Description: %s \n",description); break; } if (findEntryExists(head, surname) != NULL) printf("\nAn entry for <%s %s> is already in the catalog!\nNew entry not entered.\n",short_name,surname); else { printf("\nTry to entry <%s %s %d %s> in the catalog list!\n",short_name,surname,amount,description); InsertSort(&head,short_name, surname, amount, description); printf("\n**Entry done!**\n"); } // Maintain the list in alphabetical order by surname. } /********Uses special case code for the head end********/ void SortedInsert(catalog** headRef, catalogPointer newNode,char short_name[],char surname[],signed int amount,char description[]) { strcpy(newNode->short_name, short_name); strcpy(newNode->surname, surname); newNode->amount=amount; strcpy(newNode->description, description); // Special case for the head end if (*headRef == NULL||(*headRef)->surname >= newNode->surname) { newNode->next = *headRef; *headRef = newNode; } else { // Locate the node before the point of insertion catalogPointer current = *headRef; catalogPointer temp=current->next; while ( temp!=NULL ) { if(strcmp(temp->surname,newNode->surname)<0 ) current = temp; } newNode->next = temp; temp = newNode; } } // Given a list, change it to be in sorted order (using SortedInsert()). void InsertSort(catalog** headRef,char short_name[],char surname[],signed int amount,char description[]) { catalogPointer result = NULL; // build the answer here catalogPointer current = *headRef; // iterate over the original list catalogPointer next; while (current!=NULL) { next = current->next; // tricky - note the next pointer before we change it SortedInsert(&result,current,short_name,surname,amount,description); current = next; } *headRef = result; } Running the program I get these strange things (garbage?)... Choose your selection: enter james bond 007 gun Your command is: enter james bond 007 gun temp is:james What you entered for saving: Short Name: james SurName: Amount: 0 Description: 0T?? Try to entry james 0 0T?? in the catalog list! Entry done! Also I'm facing a problem on how to use the 'malloc' on this program. Thanks in advance. . .

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  • I need unusual ordering mysql results

    - by Patrick
    Im trying to order results ASCENDING from the current date this is what im using now; SELECT * FROM friends JOIN bdays ON bdays.user = friends.friendname WHERE username = $userid ORDER BY DATE_FORMAT(date, '%m %d') any ideas? example ordering by date now, sorts the birthdays starting at january what i need, is instead of starting the list at january, is starting it from the current date. So, instead of; January February March April May June July August September November December It will order them like this; April (current month/day) May June July August September November December January February March April (all the way up to yesterday)

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  • What could be the Java successor Oracle wants to invest in?

    - by deamon
    I've read that Oracle wants to invest into another language than Java: "On the other hand, Oracle has been particularly supportive of alternative JVM languages. Adam Messinger ( http://www.linkedin.com/in/adammessinger ) was pretty blunt at the JVM Languages Summit this year about Java the language reaching it's logical end and how Oracle is looking for a 'higher level' language to 'put significant investment into.'" But what language could be the one Oracle wants to invest in? Is there another candidate than Scala?

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  • How to make linq master detail query for 0..n relationship?

    - by JK
    Given a classic DB structure of Orders has zero or more OrderLines and OrderLine has exactly one Product, how do I write a linq query to express this? The output would be OrderNumber - OrderLine - Product Name Order-1 null null // (this order has no lines) Order-2 1 Red widget I tried this query but is not getting the orders with no lines var model = (from po in Orders from line in po.OrderLines select new { OrderNumber = po.Id, OrderLine = line.LineNumber, ProductName = line.Product.ProductDescription, } ) I think that the 2nd from is limiting the query to only those that have OrderLines, but I dont know another way to express it. LINQ is very non-obvious if you ask me!

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  • .Net SvcUtil: attributes must be optional

    - by Michel van Engelen
    Hi, I'm trying to generate C# code classes with SvcUtil.exe instead of Xsd.exe. The latter is giving me some problems. Command line: SvcUtil.exe myschema.xsd /dconly /ser:XmlSerializer Several SvcUtil problems are described and solved here: http://blog.shutupandcode.net/?p=761 One problem I can't solve is this one: Error: Type 'DatafieldDescription' in namespace '' cannot be imported. Attributes must be optional and from namespace 'http://schemas.microsoft.com/2003/10/Seri alization/'. Either change the schema so that the types can map to data contract types or use ImportXmlType or use a different serializer. ' I changed <xs:attribute name="Order" use="required"> to <xs:attribute name="Order" use="optional"> and <xs:attribute name="Order"> But the error remains. Is it possible to use attributes, or do I have to delete them all (in that case, this excercition is over)?

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  • How to use Linq to group DateTime by month and days calculation

    - by Daoming Yang
    Hi all, I have two questions: First one: I have a order list and want to group them by the created month for the reports. Each order's created datetime will be like "2010-03-13 11:17:16.000" How can I make them only group by date like "2010-03"? Note: the DateCreated is the DateTime tpye The following code is not correct. var items = orderList.GroupBy(t => t.DateCreated.Month) .Select(g => new Order() { DateCreated = g.Key }) .OrderByDescending(x => x.OrderID).ToList(); Second one: Output the full months between two dates in C# If an user choose 2010-04-08 and 2010-06-04, I want to output the 2010-04-01 and 2010-06-30. I can always get the first day and last day of the months, but I want to find out some other options Many thanks. Many thanks.

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  • RiverTrail - JavaScript GPPGU Data Parallelism

    - by JoshReuben
    Where is WebCL ? The Khronos WebCL working group is working on a JavaScript binding to the OpenCL standard so that HTML 5 compliant browsers can host GPGPU web apps – e.g. for image processing or physics for WebGL games - http://www.khronos.org/webcl/ . While Nokia & Samsung have some protype WebCL APIs, Intel has one-upped them with a higher level of abstraction: RiverTrail. Intro to RiverTrail Intel Labs JavaScript RiverTrail provides GPU accelerated SIMD data-parallelism in web applications via a familiar JavaScript programming paradigm. It extends JavaScript with simple deterministic data-parallel constructs that are translated at runtime into a low-level hardware abstraction layer. With its high-level JS API, programmers do not have to learn a new language or explicitly manage threads, orchestrate shared data synchronization or scheduling. It has been proposed as a draft specification to ECMA a (known as ECMA strawman). RiverTrail runs in all popular browsers (except I.E. of course). To get started, download a prebuilt version https://github.com/downloads/RiverTrail/RiverTrail/rivertrail-0.17.xpi , install Intel's OpenCL SDK http://www.intel.com/go/opencl and try out the interactive River Trail shell http://rivertrail.github.com/interactive For a video overview, see  http://www.youtube.com/watch?v=jueg6zB5XaM . ParallelArray the ParallelArray type is the central component of this API & is a JS object that contains ordered collections of scalars – i.e. multidimensional uniform arrays. A shape property describes the dimensionality and size– e.g. a 2D RGBA image will have shape [height, width, 4]. ParallelArrays are immutable & fluent – they are manipulated by invoking methods on them which produce new ParallelArray objects. ParallelArray supports several constructors over arrays, functions & even the canvas. // Create an empty Parallel Array var pa = new ParallelArray(); // pa0 = <>   // Create a ParallelArray out of a nested JS array. // Note that the inner arrays are also ParallelArrays var pa = new ParallelArray([ [0,1], [2,3], [4,5] ]); // pa1 = <<0,1>, <2,3>, <4.5>>   // Create a two-dimensional ParallelArray with shape [3, 2] using the comprehension constructor var pa = new ParallelArray([3, 2], function(iv){return iv[0] * iv[1];}); // pa7 = <<0,0>, <0,1>, <0,2>>   // Create a ParallelArray from canvas.  This creates a PA with shape [w, h, 4], var pa = new ParallelArray(canvas); // pa8 = CanvasPixelArray   ParallelArray exposes fluent API functions that take an elemental JS function for data manipulation: map, combine, scan, filter, and scatter that return a new ParallelArray. Other functions are scalar - reduce  returns a scalar value & get returns the value located at a given index. The onus is on the developer to ensure that the elemental function does not defeat data parallelization optimization (avoid global var manipulation, recursion). For reduce & scan, order is not guaranteed - the onus is on the dev to provide an elemental function that is commutative and associative so that scan will be deterministic – E.g. Sum is associative, but Avg is not. map Applies a provided elemental function to each element of the source array and stores the result in the corresponding position in the result array. The map method is shape preserving & index free - can not inspect neighboring values. // Adding one to each element. var source = new ParallelArray([1,2,3,4,5]); var plusOne = source.map(function inc(v) {     return v+1; }); //<2,3,4,5,6> combine Combine is similar to map, except an index is provided. This allows elemental functions to access elements from the source array relative to the one at the current index position. While the map method operates on the outermost dimension only, combine, can choose how deep to traverse - it provides a depth argument to specify the number of dimensions it iterates over. The elemental function of combine accesses the source array & the current index within it - element is computed by calling the get method of the source ParallelArray object with index i as argument. It requires more code but is more expressive. var source = new ParallelArray([1,2,3,4,5]); var plusOne = source.combine(function inc(i) { return this.get(i)+1; }); reduce reduces the elements from an array to a single scalar result – e.g. Sum. // Calculate the sum of the elements var source = new ParallelArray([1,2,3,4,5]); var sum = source.reduce(function plus(a,b) { return a+b; }); scan Like reduce, but stores the intermediate results – return a ParallelArray whose ith elements is the results of using the elemental function to reduce the elements between 0 and I in the original ParallelArray. // do a partial sum var source = new ParallelArray([1,2,3,4,5]); var psum = source.scan(function plus(a,b) { return a+b; }); //<1, 3, 6, 10, 15> scatter a reordering function - specify for a certain source index where it should be stored in the result array. An optional conflict function can prevent an exception if two source values are assigned the same position of the result: var source = new ParallelArray([1,2,3,4,5]); var reorder = source.scatter([4,0,3,1,2]); // <2, 4, 5, 3, 1> // if there is a conflict use the max. use 33 as a default value. var reorder = source.scatter([4,0,3,4,2], 33, function max(a, b) {return a>b?a:b; }); //<2, 33, 5, 3, 4> filter // filter out values that are not even var source = new ParallelArray([1,2,3,4,5]); var even = source.filter(function even(iv) { return (this.get(iv) % 2) == 0; }); // <2,4> Flatten used to collapse the outer dimensions of an array into a single dimension. pa = new ParallelArray([ [1,2], [3,4] ]); // <<1,2>,<3,4>> pa.flatten(); // <1,2,3,4> Partition used to restore the original shape of the array. var pa = new ParallelArray([1,2,3,4]); // <1,2,3,4> pa.partition(2); // <<1,2>,<3,4>> Get return value found at the indices or undefined if no such value exists. var pa = new ParallelArray([0,1,2,3,4], [10,11,12,13,14], [20,21,22,23,24]) pa.get([1,1]); // 11 pa.get([1]); // <10,11,12,13,14>

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  • Linq Grouping by 2 keys as a one

    - by Evgeny
    Hello! I write a simple OLAP viewer for my web-site. Here are the classes (abstract example): Employee { ID; Name; Roles[]; //What Employee can do } Order { Price; Employee Manager; Employee Executive; //Maybe wrong english. The person which perform order } Employee can be Manager and Executive in the order at the same time. This means that Employee role is not fixed. I have to group orders by employees and finally get IGrouping with Employee key. So .GroupBy(el=new {el.Manager,el.Executive}) is not allowed. I considered some tricks with IEqualityComparable, but found no solution. If somrbody will help I'll be vary glad, thank you.

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  • Off-Page SEO Tactics - General

    Off-page or off the page means just that - things that we can do to help our website rank more highly in the search engines that are not carried out on the site itself. There is really only one way we can use off-page techniques to rank our site higher and that is to encourage backlinks. How do we do that though?

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  • The History of Digital Storage [Infographic]

    - by Jason Fitzpatrick
    From punch cards to hard drives to cloud based storage, how we stash our data away has changed quite a bit in the last century. Courtesy of Mashable, we have an infographic detailing the evolution of storage and comparing storage size, speed, and prices over the decades. Hit up the link below for a higher resolution image. The History of Digital Storage [Mashable] How To Create a Customized Windows 7 Installation Disc With Integrated Updates How to Get Pro Features in Windows Home Versions with Third Party Tools HTG Explains: Is ReadyBoost Worth Using?

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  • Programmatically get screenshot of page

    - by Ender
    I'm writing a specialized crawler and parser for internal use and I require the ability to take a screenshot of a web page in order to check what colours are being used throughout. The program will take in around ten web addresses and will save them as a bitmap image, from there I plan to use LockBits in order to create a list of the five most used colours within the image. To my knowledge it's the easiest way to get the colours used within a web page but if there is an easier way to do it please chime in with your suggestions. Anyway, I was going to use this program until I saw the price tag. I'm also fairly new to C#, having only used it for a few months. Can anyone provide me with a solution to my problem of taking a screenshot of a web page in order to extract the colour scheme?

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  • Will Outsourcing Your SEO Increase Your MLM Leads?

    Search engine optimization or SEO is absolutely booming in the MLM home business industry right now. Configuring your MLM website to look attractive to search engines will raise your page rank, put you higher in search results, and increase your organic traffic, and thus MLM lead generation.

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  • Is testability alone justification for dependency injection?

    - by fearofawhackplanet
    The advantages of DI, as far as I am aware, are: Reduced Dependencies More Reusable Code More Testable Code More Readable Code Say I have a repository, OrderRepository, which acts as a repository for an Order object generated through a Linq to Sql dbml. I can't make my orders repository generic as it performs mapping between the Linq Order entity and my own Order POCO domain class. Since the OrderRepository by necessity is dependent on a specific Linq to Sql DataContext, parameter passing of the DataContext can't really be said to make the code reuseable or reduce dependencies in any meaningful way. It also makes the code harder to read, as to instantiate the repository I now need to write new OrdersRepository(new MyLinqDataContext()) which additionally is contrary to the main purpose of the repository, that being to abstract/hide the existence of the DataContext from consuming code. So in general I think this would be a pretty horrible design, but it would give the benefit of facilitating unit testing. Is this enough justification? Or is there a third way? I'd be very interested in hearing opinions.

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  • SEO - Definition & Purpose

    It stands for Search Engine Optimization. It is a process by which the website is ranked higher and promoted on a large scale and that leads to more business for the owner. In order to understand what this process is, you need to understand some details pertaining to search engines and websites. Now almost every company and trader has built their websites to promote their business since they can make a global approach through the internet.

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  • Sql Paging/Sorting - Efficent method with dynamic sort?

    - by dmose
    I'm trying to implement this style of paging: http://www.4guysfromrolla.com/webtech/042606-1.shtml CREATE PROCEDURE [dbo].[usp_PageResults_NAI] ( @startRowIndex int, @maximumRows int ) AS DECLARE @first_id int, @startRow int -- A check can be added to make sure @startRowIndex isn't > count(1) -- from employees before doing any actual work unless it is guaranteed -- the caller won't do that -- Get the first employeeID for our page of records SET ROWCOUNT @startRowIndex SELECT @first_id = employeeID FROM employees ORDER BY employeeid -- Now, set the row count to MaximumRows and get -- all records >= @first_id SET ROWCOUNT @maximumRows SELECT e.*, d.name as DepartmentName FROM employees e INNER JOIN Departments D ON e.DepartmentID = d.DepartmentID WHERE employeeid >= @first_id ORDER BY e.EmployeeID SET ROWCOUNT 0 GO This method works great, however, is it possible to use this method and have dynamic field sorting? If we change this to SELECT e.*, d.name as DepartmentName FROM employees e INNER JOIN Departments D ON e.DepartmentID = d.DepartmentID WHERE employeeid >= @first_id ORDER BY e.FirstName DESC It breaks the sorting... Is there any way to combine this method of paging with the ability to sort on different fields?

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  • complex mysql query problem

    - by Scarface
    Hey guys I have a query that selects data and organizes but not in the correct order. What I want to do is select all the comments for a user in that week and sort it by each topic, then sort the cluster by the latest timestamp of each comment in their respective cluster. My current query selects the right data, but in seemingly random order. Does anyone have any ideas? select * from ( SELECT topic.topic_title, topic.topic_id FROM comments JOIN topic ON topic.topic_id=comments.topic_id WHERE comments.user='$user' AND comments.timestamp>$week order by comments.timestamp desc) derived_table group by topic_id

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  • CodeIgniter based e-shop, shipping and gift address design problem

    - by alexander
    While building an ecommerce platform I have run into design problems. I'm working with the built-in CodeIgniter's cart class. It stores all the cart information in session. Let say that cart has already been filled with products and user clicks checkout. When should I store order in database? Just after that click or after several steps of gathering information and stoing it in session? How to deal with additional features like different shipping methods? Should I add it to the basket first and get additional (gift address) to session? I dont want to store it in database because of the relation between gift address and order is needed and since I dont know what's the ID of the order. I'm puzzled :) Additionally I think its crucial to keep cart aware of shipping methods and additional bought services (by selecting gift address there is an extra fee) because the cart content is just like an reciept? In brief, what is the best practice to process checkout?

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  • Intel Server Strategy Shift with Sandy Bridge EN & EP

    - by jchang
    The arrival of the Sandy Bridge EN and EP processors, expected in early 2012, will mark the completion of a significant shift in Intel server strategy. For the longest time 1995-2009, the strategy had been to focus on producing a premium processor designed for 4-way systems that might also be used in 8-way systems and higher. The objective for 2-way systems was use the desktop processor that later had a separate brand and different package & socket to leverage the low cost structure in driving...(read more)

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  • Jquery each loop with json array

    - by Ben
    I'm trying to use Jquery's each loop to go through this Json and add it to a div named #contentHere. The Json is as follows: { "justIn": [ { "textId": "123", "text": "Hello", "textType": "Greeting" }, { "textId": "514", "text":"What's up?", "textType": "Question" }, { "textId": "122", "text":"Come over here", "textType": "Order" } ], "recent": [ { "textId": "1255", "text": "Hello", "textType": "Greeting" }, { "textId": "6564", "text":"What's up?", "textType": "Question" }, { "textId": "0192", "text":"Come over here", "textType": "Order" } ], "old": [ { "textId": "5213", "text": "Hello", "textType": "Greeting" }, { "textId": "9758", "text":"What's up?", "textType": "Question" }, { "textId": "7655", "text":"Come over here", "textType": "Order" } ] } I'm getting this Json through use of this code: $.get("data.php", function(data){ }) Any solutions?

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  • SEO-ing Your Website

    What is SEO? The abbreviation SEO stands for Search Engine Optimization. It is the process of improving the volume of traffic to a web site via search engines through relevant keywords. The more traffic a website gets, the higher his ranking will be in search engine results. This is essentially SEO promotion and it is used by many webmasters today.

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  • Recent uploaded slides for the Upgrade Talks last week

    - by Mike Dietrich
    Welcome 2011 :-) And here you'll find the newest talks Carol, Roy and Brian delivered last week in several cities (please find the also in the DOWNLOAD SLIDES section on the right side of this blog): Upgrade Methods and Upgrade Planning: Click here to Download and use the keyword: roy2011 +500 Slides Upgrade Workshop Presentation: Click here to Download and use the keyword (Schlüsselwort): upgrade112 Hope you had a nice weekend and wonderful weather, too, as we had yesterday south of Munich. Click pic for a higher resolution: Starnberg Lake - View towards the Alps

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  • Why Is Vertical Resolution Monitor Resolution so Often a Multiple of 360?

    - by Jason Fitzpatrick
    Stare at a list of monitor resolutions long enough and you might notice a pattern: many of the vertical resolutions, especially those of gaming or multimedia displays, are multiples of 360 (720, 1080, 1440, etc.) But why exactly is this the case? Is it arbitrary or is there something more at work? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Trojandestroy recently noticed something about his display interface and needs answers: YouTube recently added 1440p functionality, and for the first time I realized that all (most?) vertical resolutions are multiples of 360. Is this just because the smallest common resolution is 480×360, and it’s convenient to use multiples? (Not doubting that multiples are convenient.) And/or was that the first viewable/conveniently sized resolution, so hardware (TVs, monitors, etc) grew with 360 in mind? Taking it further, why not have a square resolution? Or something else unusual? (Assuming it’s usual enough that it’s viewable). Is it merely a pleasing-the-eye situation? So why have the display be a multiple of 360? The Answer SuperUser contributor User26129 offers us not just an answer as to why the numerical pattern exists but a history of screen design in the process: Alright, there are a couple of questions and a lot of factors here. Resolutions are a really interesting field of psychooptics meeting marketing. First of all, why are the vertical resolutions on youtube multiples of 360. This is of course just arbitrary, there is no real reason this is the case. The reason is that resolution here is not the limiting factor for Youtube videos – bandwidth is. Youtube has to re-encode every video that is uploaded a couple of times, and tries to use as little re-encoding formats/bitrates/resolutions as possible to cover all the different use cases. For low-res mobile devices they have 360×240, for higher res mobile there’s 480p, and for the computer crowd there is 360p for 2xISDN/multiuser landlines, 720p for DSL and 1080p for higher speed internet. For a while there were some other codecs than h.264, but these are slowly being phased out with h.264 having essentially ‘won’ the format war and all computers being outfitted with hardware codecs for this. Now, there is some interesting psychooptics going on as well. As I said: resolution isn’t everything. 720p with really strong compression can and will look worse than 240p at a very high bitrate. But on the other side of the spectrum: throwing more bits at a certain resolution doesn’t magically make it better beyond some point. There is an optimum here, which of course depends on both resolution and codec. In general: the optimal bitrate is actually proportional to the resolution. So the next question is: what kind of resolution steps make sense? Apparently, people need about a 2x increase in resolution to really see (and prefer) a marked difference. Anything less than that and many people will simply not bother with the higher bitrates, they’d rather use their bandwidth for other stuff. This has been researched quite a long time ago and is the big reason why we went from 720×576 (415kpix) to 1280×720 (922kpix), and then again from 1280×720 to 1920×1080 (2MP). Stuff in between is not a viable optimization target. And again, 1440P is about 3.7MP, another ~2x increase over HD. You will see a difference there. 4K is the next step after that. Next up is that magical number of 360 vertical pixels. Actually, the magic number is 120 or 128. All resolutions are some kind of multiple of 120 pixels nowadays, back in the day they used to be multiples of 128. This is something that just grew out of LCD panel industry. LCD panels use what are called line drivers, little chips that sit on the sides of your LCD screen that control how bright each subpixel is. Because historically, for reasons I don’t really know for sure, probably memory constraints, these multiple-of-128 or multiple-of-120 resolutions already existed, the industry standard line drivers became drivers with 360 line outputs (1 per subpixel). If you would tear down your 1920×1080 screen, I would be putting money on there being 16 line drivers on the top/bottom and 9 on one of the sides. Oh hey, that’s 16:9. Guess how obvious that resolution choice was back when 16:9 was ‘invented’. Then there’s the issue of aspect ratio. This is really a completely different field of psychology, but it boils down to: historically, people have believed and measured that we have a sort of wide-screen view of the world. Naturally, people believed that the most natural representation of data on a screen would be in a wide-screen view, and this is where the great anamorphic revolution of the ’60s came from when films were shot in ever wider aspect ratios. Since then, this kind of knowledge has been refined and mostly debunked. Yes, we do have a wide-angle view, but the area where we can actually see sharply – the center of our vision – is fairly round. Slightly elliptical and squashed, but not really more than about 4:3 or 3:2. So for detailed viewing, for instance for reading text on a screen, you can utilize most of your detail vision by employing an almost-square screen, a bit like the screens up to the mid-2000s. However, again this is not how marketing took it. Computers in ye olden days were used mostly for productivity and detailed work, but as they commoditized and as the computer as media consumption device evolved, people didn’t necessarily use their computer for work most of the time. They used it to watch media content: movies, television series and photos. And for that kind of viewing, you get the most ‘immersion factor’ if the screen fills as much of your vision (including your peripheral vision) as possible. Which means widescreen. But there’s more marketing still. When detail work was still an important factor, people cared about resolution. As many pixels as possible on the screen. SGI was selling almost-4K CRTs! The most optimal way to get the maximum amount of pixels out of a glass substrate is to cut it as square as possible. 1:1 or 4:3 screens have the most pixels per diagonal inch. But with displays becoming more consumery, inch-size became more important, not amount of pixels. And this is a completely different optimization target. To get the most diagonal inches out of a substrate, you want to make the screen as wide as possible. First we got 16:10, then 16:9 and there have been moderately successful panel manufacturers making 22:9 and 2:1 screens (like Philips). Even though pixel density and absolute resolution went down for a couple of years, inch-sizes went up and that’s what sold. Why buy a 19″ 1280×1024 when you can buy a 21″ 1366×768? Eh… I think that about covers all the major aspects here. There’s more of course; bandwidth limits of HDMI, DVI, DP and of course VGA played a role, and if you go back to the pre-2000s, graphics memory, in-computer bandwdith and simply the limits of commercially available RAMDACs played an important role. But for today’s considerations, this is about all you need to know. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • Getting a sorted distinct list from mySQL

    - by Stomped
    Goal I'l like to get a list of unique FID's ordered by the the one which has most recently been changed. In this sample table it should return FIDs in the order of 150, 194, 122 Example Data ID FID changeDate ---------------------------------------------- 1 194 2010-04-01 2 122 2010-04-02 3 194 2010-04-03 4 150 2010-04-04 My Attempt I thought distinct and order by would do the trick. I initially tried: SELECT distinct `FID` FROM `tblHistory` WHERE 1 ORDER BY changeDate desc # Returns 150, 122, 194 using GROUP BY has the same result. I'm just barely a SQL amateur, and I'm a bit hung up. What seems to be happening is the aggregating functions find the first occurrence of each and then perform the sort. Is there a way I can get the result I want straight from mySQL or do I have to grab all the data and then sort it in the PHP?

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