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  • What strategy should be employed to access Facebook data offline?

    - by user686021
    I'm working on a project similar to Klout which provides detail about how you influence other people and who influenced you. We'll be fetching data from few social networking sites (i.e linked in, facebook, twitter etc) to analyze how users interacts with one another. For that we need to parse the data and store it in db and have to analyze it so that strength of relation of two user can be decided. We'll be accessing data offline as well to provide them with accurate results. If we consider facebook activities, we need to have access to Facebook users' news feed, wall data which includes likes,comments,shares etc. To decide how one user influence other, we'll store all the data and analyze it. I need suggestions on what steps need to be taken for great performance. We'll be using ASP.Net(C#) Web forms, SQL Server, jQuery. Main concern is parsing of data, it's storage and retrieval with least overhead. For that I've summarized few points as below : Should we switch over to document-oriented database, like MongoDB or RavenDB for the whole app or part of it even though none of team member have experience with them? Should we use SQL Server Analysis service? Is there any other library than Json.NET for parsing data? Is it advisable to use any C# library over FQL + GET Request ? I've tried to provide as much info as possible. Please share your views for the same.

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  • Is application-specific data required for good unit testing?

    - by stinkycheeseman
    I am writing unit tests for a fairly simple function that depends on a fairly complicated set of data. Essentially, the object I am manipulating represents a graph and this function determines whether to chart a line, bar, or pie chart based on the data that came back from the server. This is a simplified version, using jQuery: setDefaultChartType: function (graphObject) { var prop1 = graphObject.properties.key; var numCols = 0; $.each(graphObject.columns, function (colIndex, column) { numCols++; }); if ( numCols > 6 || ( prop1 > 1 && graphObject.data.length == 1) ) { graphObject.setChartType("line"); } else if ( numCols <=6 && prop1 == 1 ) { graphObject.setChartType("bar"); } else if ( numCols <=6 && prop1 > 1 ) { graphObject.setChartType("pie"); } } My question is, should I use mock data that is procured from the actual database? Or can I just fabricate data that fits the different cases? I'm afraid that fabricating data will not expose bugs arising from changes in the database, but on the other hand, it would require a lot more effort to keep the test data up-to-date that I'm not sure is necessary.

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  • Wednesday at Oracle OpenWorld 2012 - Must See Session: “Event-Driven Patterns and Best Practices: Even More Important with Big Data”

    - by Lionel Dubreuil
    Don’t miss this “CON8636 - Event-Driven Patterns and Best Practices: Even More Important with Big Data“ session: Speakers: Faisal Nazir - Senior Solutions Architect, Motorola Shinichiro Takahashi - Senior Manager, Service Platform Department, NTT DOCOMO, INC. Robin Smith - Product Management/Strategy Director - Oracle Event Processing, Oracle Date: Wednesday, Oct 3 Time: 10:15 AM - 11:15 AM Location: Moscone South - 310 As the demand for big data analytics and integration grows across all industries, this session focuses on the role of the Oracle event-driven solution platform in delivering vital real-time integrated analysis intelligence to the data streams consumed and emitted from these large distributed data stores. Objectives for this session are to: Increase awareness of Oracle Event Processing, showcasing tight alignment with big data solutions Highlight emerging usage patterns in relation to streaming event data and distributed data stores Show a significant Oracle competitive advantage over IBM solutions advertised in this domain Normal 0 false false false EN-US X-NONE X-NONE /* 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}

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  • Dynamic DataGrid columns in WPF DataGrid based on the underlying set of data (and their type)

    - by StatsMan
    Hello everyone, I've got kind of a conceptual question. I am in the process of wrapping some statistics classes I wrote into WPF. For that I have two DataGrid(-Views, currently in WinForms). In one DataGrid each row represents a column in the other. There I can set-up different variables (as in mathematical/statistical variables) with fields like "Header", "DataType", "ValidationBehaviour", "DisplayType". There I can also set-up how it should be displayed. Some Columns can automatically be set to ComboBoxColumns, some TextBoxColumns, and so on and so forth. So, now once I've set-up these Columns I can go to the other grid and enter my data. I may, for instance, have generated (in grid 1) one Column called "Annual Gross Salary" with input of numerical values. Another Column called "Education" with "0=NoEducation", "1=College Level", "3=Universitary" etc. These labels are displayed as text in the combobox and my statistics engine behind then selects the respective value (0-3) for calculations (i.e. ordinal, nominal variables). Sooo. In WinForms I could basically generate all the columns by hand in code and then add my data in the respective cells/rows. Now in WPF I thought that must be easy to realise. However, yesterday I got started with ICustomPropertyDescriptor which (maybe I was too thick) didn't give me the results I was looking for. Basically, I just need to be able to dynamically generate columns (and rows) with different Layout, Controls (ComboBox, simple Input, DateTimes) based on the data that I have. But I don't really know how to go about it? So here in summary: DataGrid 1 Purpose is to display columns that have been specified in DataGrid 2 In rows, the user can add any kind of data in the rows below the columns that is allowed as to the columns specifications DataGrid 2 Each row in this grid represents a column in DataGrid 1 Contains fields like Name/Header, DataType, Validation Behaviour, Default Value, Data Formatting, etc. Also contains a function to be able to set-up how it should be displayed. The user can select from, for instance, ComboBoxColumn (and also add the available options), DateTime, normal TextBox, CheckBox etc. After finishing adding a row it will automatically appear as a new column in DataGrid 1 I'd appreciate any kind of pointer into the right direction. Thanks very, very much in advance! :)

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  • JsTree v1.0 - How to manipulate effectively the data from the backend to render the trees and operate correctly?

    - by Jean Paul
    Backend info: PHP 5 / MySQL URL: http://github.com/downloads/vakata/jstree/jstree_pre1.0_fix_1.zip Table structure for table discussions_tree -- CREATE TABLE IF NOT EXISTS `discussions_tree` ( `id` int(11) NOT NULL AUTO_INCREMENT, `parent_id` int(11) NOT NULL DEFAULT '0', `user_id` int(11) NOT NULL DEFAULT '0', `label` varchar(16) DEFAULT NULL, `position` bigint(20) unsigned NOT NULL DEFAULT '0', `left` bigint(20) unsigned NOT NULL DEFAULT '0', `right` bigint(20) unsigned NOT NULL DEFAULT '0', `level` bigint(20) unsigned NOT NULL DEFAULT '0', `type` varchar(255) CHARACTER SET utf8 COLLATE utf8_unicode_ci DEFAULT NULL, `h_label` varchar(16) NOT NULL DEFAULT '', `fulllabel` varchar(255) DEFAULT NULL, UNIQUE KEY `uidx_3` (`id`), KEY `idx_1` (`user_id`), KEY `idx_2` (`parent_id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=8 ; /*The first element should in my understanding not even be shown*/ INSERT INTO `discussions_tree` (`id`, `parent_id`, `user_id`, `label`, `position`, `left`, `right`, `level`, `type`, `h_label`, `fulllabel`) VALUES (0, 0, 0, 'Contacts', 0, 1, 1, 0, NULL, '', NULL); INSERT INTO `discussions_tree` (`id`, `parent_id`, `user_id`, `label`, `position`, `left`, `right`, `level`, `type`, `h_label`, `fulllabel`) VALUES (1, 0, 0, 'How to Tag', 1, 2, 2, 0, 'drive', '', NULL); Front End : I've simplified the logic, it has 6 trees actually inside of a panel and that works fine $array = array("Discussions"); $id_arr = array("d"); $nid = 0; foreach ($array as $k=> $value) { $nid++; ?> <li id="<?=$value?>" class="label"> <a href='#<?=$value?>'><span> <?=$value?> </span></a> <div class="sub-menu" style="height:auto; min-height:120px; background-color:#E5E5E5" > <div class="menu" id="menu_<?=$id_arr[$k]?>" style="position:relative; margin-left:56%"> <img src="./js/jsTree/create.png" alt="" id="create" title="Create" > <img src="./js/jsTree/rename.png" alt="" id="rename" title="Rename" > <img src="./js/jsTree/remove.png" alt="" id="remove" title="Delete"> <img src="./js/jsTree/cut.png" alt="" id="cut" title="Cut" > <img src="./js/jsTree/copy.png" alt="" id="copy" title="Copy"> <img src="./js/jsTree/paste.png" alt="" id="paste" title="Paste"> </div> <div id="<?=$id_arr[$k]?>" class="jstree_container"></div> </div> </li> <!-- JavaScript neccessary for this tree : <?=$value?> --> <script type="text/javascript" > jQuery(function ($) { $("#<?=$id_arr[$k]?>").jstree({ // List of active plugins used "plugins" : [ "themes", "json_data", "ui", "crrm" , "hotkeys" , "types" , "dnd", "contextmenu"], // "ui" :{ "initially_select" : ["#node_"+ $nid ] } , "crrm": { "move": { "always_copy": "multitree" }, "input_width_limit":128 }, "core":{ "strings":{ "new_node" : "New Tag" }}, "themes": {"theme": "classic"}, "json_data" : { "ajax" : { "url" : "./js/jsTree/server-<?=$id_arr[$k]?>.php", "data" : function (n) { // the result is fed to the AJAX request `data` option return { "operation" : "get_children", "id" : n.attr ? n.attr("id").replace("node_","") : 1, "state" : "", "user_id": <?=$uid?> }; } } } , "types" : { "max_depth" : -1, "max_children" : -1, "types" : { // The default type "default" : { "hover_node":true, "valid_children" : [ "default" ], }, // The `drive` nodes "drive" : { // can have files and folders inside, but NOT other `drive` nodes "valid_children" : [ "default", "folder" ], "hover_node":true, "icon" : { "image" : "./js/jsTree/root.png" }, // those prevent the functions with the same name to be used on `drive` nodes.. internally the `before` event is used "start_drag" : false, "move_node" : false, "remove_node" : false } } }, "contextmenu" : { "items" : customMenu , "select_node": true} }) //Hover function binded to jstree .bind("hover_node.jstree", function (e, data) { $('ul li[rel="drive"], ul li[rel="default"], ul li[rel=""]').each(function(i) { $(this).find("a").attr('href', $(this).attr("id")+".php" ); }) }) //Create function binded to jstree .bind("create.jstree", function (e, data) { $.post( "./js/jsTree/server-<?=$id_arr[$k]?>.php", { "operation" : "create_node", "id" : data.rslt.parent.attr("id").replace("node_",""), "position" : data.rslt.position, "label" : data.rslt.name, "href" : data.rslt.obj.attr("href"), "type" : data.rslt.obj.attr("rel"), "user_id": <?=$uid?> }, function (r) { if(r.status) { $(data.rslt.obj).attr("id", "node_" + r.id); } else { $.jstree.rollback(data.rlbk); } } ); }) //Remove operation .bind("remove.jstree", function (e, data) { data.rslt.obj.each(function () { $.ajax({ async : false, type: 'POST', url: "./js/jsTree/server-<?=$id_arr[$k]?>.php", data : { "operation" : "remove_node", "id" : this.id.replace("node_",""), "user_id": <?=$uid?> }, success : function (r) { if(!r.status) { data.inst.refresh(); } } }); }); }) //Rename operation .bind("rename.jstree", function (e, data) { data.rslt.obj.each(function () { $.ajax({ async : true, type: 'POST', url: "./js/jsTree/server-<?=$id_arr[$k]?>.php", data : { "operation" : "rename_node", "id" : this.id.replace("node_",""), "label" : data.rslt.new_name, "user_id": <?=$uid?> }, success : function (r) { if(!r.status) { data.inst.refresh(); } } }); }); }) //Move operation .bind("move_node.jstree", function (e, data) { data.rslt.o.each(function (i) { $.ajax({ async : false, type: 'POST', url: "./js/jsTree/server-<?=$id_arr[$k]?>.php", data : { "operation" : "move_node", "id" : $(this).attr("id").replace("node_",""), "ref" : data.rslt.cr === -1 ? 1 : data.rslt.np.attr("id").replace("node_",""), "position" : data.rslt.cp + i, "label" : data.rslt.name, "copy" : data.rslt.cy ? 1 : 0, "user_id": <?=$uid?> }, success : function (r) { if(!r.status) { $.jstree.rollback(data.rlbk); } else { $(data.rslt.oc).attr("id", "node_" + r.id); if(data.rslt.cy && $(data.rslt.oc).children("UL").length) { data.inst.refresh(data.inst._get_parent(data.rslt.oc)); } } } }); }); }); // This is for the context menu to bind with operations on the right clicked node function customMenu(node) { // The default set of all items var control; var items = { createItem: { label: "Create", action: function (node) { return {createItem: this.create(node) }; } }, renameItem: { label: "Rename", action: function (node) { return {renameItem: this.rename(node) }; } }, deleteItem: { label: "Delete", action: function (node) { return {deleteItem: this.remove(node) }; }, "separator_after": true }, copyItem: { label: "Copy", action: function (node) { $(node).addClass("copy"); return {copyItem: this.copy(node) }; } }, cutItem: { label: "Cut", action: function (node) { $(node).addClass("cut"); return {cutItem: this.cut(node) }; } }, pasteItem: { label: "Paste", action: function (node) { $(node).addClass("paste"); return {pasteItem: this.paste(node) }; } } }; // We go over all the selected items as the context menu only takes action on the one that is right clicked $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element) { if ( $(element).attr("id") != $(node).attr("id") ) { // Let's deselect all nodes that are unrelated to the context menu -- selected but are not the one right clicked $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); } }); //if any previous click has the class for copy or cut $("#<?=$id_arr[$k]?>").find("li").each(function(index,element) { if ($(element) != $(node) ) { if( $(element).hasClass("copy") || $(element).hasClass("cut") ) control=1; } else if( $(node).hasClass("cut") || $(node).hasClass("copy")) { control=0; } }); //only remove the class for cut or copy if the current operation is to paste if($(node).hasClass("paste") ) { control=0; // Let's loop through all elements and try to find if the paste operation was done already $("#<?=$id_arr[$k]?>").find("li").each(function(index,element) { if( $(element).hasClass("copy") ) $(this).removeClass("copy"); if ( $(element).hasClass("cut") ) $(this).removeClass("cut"); if ( $(element).hasClass("paste") ) $(this).removeClass("paste"); }); } switch (control) { //Remove the paste item from the context menu case 0: switch ($(node).attr("rel")) { case "drive": delete items.renameItem; delete items.deleteItem; delete items.cutItem; delete items.copyItem; delete items.pasteItem; break; case "default": delete items.pasteItem; break; } break; //Remove the paste item from the context menu only on the node that has either copy or cut added class case 1: if( $(node).hasClass("cut") || $(node).hasClass("copy") ) { switch ($(node).attr("rel")) { case "drive": delete items.renameItem; delete items.deleteItem; delete items.cutItem; delete items.copyItem; delete items.pasteItem; break; case "default": delete items.pasteItem; break; } } else //Re-enable it on the clicked node that does not have the cut or copy class { switch ($(node).attr("rel")) { case "drive": delete items.renameItem; delete items.deleteItem; delete items.cutItem; delete items.copyItem; break; } } break; //initial state don't show the paste option on any node default: switch ($(node).attr("rel")) { case "drive": delete items.renameItem; delete items.deleteItem; delete items.cutItem; delete items.copyItem; delete items.pasteItem; break; case "default": delete items.pasteItem; break; } break; } return items; } $("#menu_<?=$id_arr[$k]?> img").hover( function () { $(this).css({'cursor':'pointer','outline':'1px double teal'}) }, function () { $(this).css({'cursor':'none','outline':'1px groove transparent'}) } ); $("#menu_<?=$id_arr[$k]?> img").click(function () { switch(this.id) { //Create only the first element case "create": if ( $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).length ) { $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element){ switch(index) { case 0: $("#<?=$id_arr[$k]?>").jstree("create", '#'+$(element).attr("id"), null, /*{attr : {href: '#' }}*/null ,null, false); break; default: $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); break; } }); } else { $.facebox('<p class=\'p_inner error bold\'>A selection needs to be made to work with this operation'); setTimeout(function(){ $.facebox.close(); }, 2000); } break; //REMOVE case "remove": if ( $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).length ) { $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element){ //only execute if the current node is not the first one (drive) if( $(element).attr("id") != $("div.jstree > ul > li").first().attr("id") ) { $("#<?=$id_arr[$k]?>").jstree("remove",'#'+$(element).attr("id")); } else $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); }); } else { $.facebox('<p class=\'p_inner error bold\'>A selection needs to be made to work with this operation'); setTimeout(function(){ $.facebox.close(); }, 2000); } break; //RENAME NODE only one selection case "rename": if ( $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).length ) { $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element){ if( $(element).attr("id") != $("div.jstree > ul > li").first().attr("id") ) { switch(index) { case 0: $("#<?=$id_arr[$k]?>").jstree("rename", '#'+$(element).attr("id") ); break; default: $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); break; } } else $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); }); } else { $.facebox('<p class=\'p_inner error bold\'>A selection needs to be made to work with this operation'); setTimeout(function(){ $.facebox.close(); }, 2000); } break; //Cut case "cut": if ( $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).length ) { $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element){ switch(index) { case 0: $("#<?=$id_arr[$k]?>").jstree("cut", '#'+$(element).attr("id")); $.facebox('<p class=\'p_inner teal\'>Operation "Cut" successfully done.<p class=\'p_inner teal bold\'>Where to place it?'); setTimeout(function(){ $.facebox.close(); $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id")); }, 2000); break; default: $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); break; } }); } else { $.facebox('<p class=\'p_inner error bold\'>A selection needs to be made to work with this operation'); setTimeout(function(){ $.facebox.close(); }, 2000); } break; //Copy case "copy": if ( $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).length ) { $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element){ switch(index) { case 0: $("#<?=$id_arr[$k]?>").jstree("copy", '#'+$(element).attr("id")); $.facebox('<p class=\'p_inner teal\'>Operation "Copy": Successfully done.<p class=\'p_inner teal bold\'>Where to place it?'); setTimeout(function(){ $.facebox.close(); $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); }, 2000); break; default: $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); break; } }); } else { $.facebox('<p class=\'p_inner error bold\'>A selection needs to be made to work with this operation'); setTimeout(function(){ $.facebox.close(); }, 2000); } break; case "paste": if ( $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).length ) { $.jstree._reference("#<?=$id_arr[$k]?>").get_selected(false, true).each(function(index,element){ switch(index) { case 0: $("#<?=$id_arr[$k]?>").jstree("paste", '#'+$(element).attr("id")); break; default: $("#<?=$id_arr[$k]?>").jstree("deselect_node", '#'+$(element).attr("id") ); break; } }); } else { $.facebox('<p class=\'p_inner error bold\'>A selection needs to be made to work with this operation'); setTimeout(function(){ $.facebox.close(); }, 2000); } break; } }); <? } ?> server.php $path='../../../..'; require_once "$path/phpfoo/dbif.class"; require_once "$path/global.inc"; // Database config & class $db_config = array( "servername"=> $dbHost, "username" => $dbUser, "password" => $dbPW, "database" => $dbName ); if(extension_loaded("mysqli")) require_once("_inc/class._database_i.php"); else require_once("_inc/class._database.php"); //Tree class require_once("_inc/class.ctree.php"); $dbLink = new dbif(); $dbErr = $dbLink->connect($dbName,$dbUser,$dbPW,$dbHost); $jstree = new json_tree(); if(isset($_GET["reconstruct"])) { $jstree->_reconstruct(); die(); } if(isset($_GET["analyze"])) { echo $jstree->_analyze(); die(); } $table = '`discussions_tree`'; if($_REQUEST["operation"] && strpos($_REQUEST["operation"], "_") !== 0 && method_exists($jstree, $_REQUEST["operation"])) { foreach($_REQUEST as $k => $v) { switch($k) { case 'user_id': //We are passing the user_id from the $_SESSION on each request and trying to pick up the min and max value from the table that matches the 'user_id' $sql = "SELECT max(`right`) , min(`left`) FROM $table WHERE `user_id`=$v"; //If the select does not return any value then just let it be :P if (!list($right, $left)=$dbLink->getRow($sql)) { $sql = $dbLink->dbSubmit("UPDATE $table SET `user_id`=$v WHERE `id` = 1 AND `parent_id` = 0"); $sql = $dbLink->dbSubmit("UPDATE $table SET `user_id`=$v WHERE `parent_id` = 1 AND `label`='How to Tag' "); } else { $sql = $dbLink->dbSubmit("UPDATE $table SET `user_id`=$v, `right`=$right+2 WHERE `id` = 1 AND `parent_id` = 0"); $sql = $dbLink->dbSubmit("UPDATE $table SET `user_id`=$v, `left`=$left+1, `right`=$right+1 WHERE `parent_id` = 1 AND `label`='How to Tag' "); } break; } } header("HTTP/1.0 200 OK"); header('Content-type: application/json; charset=utf-8'); header("Cache-Control: no-cache, must-revalidate"); header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); header("Pragma: no-cache"); echo $jstree->{$_REQUEST["operation"]}($_REQUEST); die(); } header("HTTP/1.0 404 Not Found"); ?> The problem: DND *(Drag and Drop) works, Delete works, Create works, Rename works, but Copy, Cut and Paste don't work

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  • NSObject release destroys local copy of object's data

    - by Spider-Paddy
    I know this is something stupid on my part but I don't get what's happening. I create an object that fetches data & puts it into an array in a specific format, since it fetches asynchronously (has to download & parse data) I put a delegate method into the object that needs the data so that the data fetching object copies it's formatted array into an array in the calling object. The problem is that when the data fetching object is released, the copy it created in the caller is being erased, code is: In .h file @property (nonatomic, retain) NSArray *imagesDataSource; In .m file // Fetch item details ImagesParser *imagesParserObject = [[ImagesParser alloc] init:self]; [imagesParserObject getArticleImagesOfArticleId:(NSInteger)currentArticleId]; [imagesParserObject release] <-- problematic release // Called by parser when images parsing is finished -(void)imagesDataTransferComplete:(ImagesParser *)imagesParserObject { self.imagesDataSource = [ImagesParserObject.returnedArray copy]; // copy array to local variable // If there are more pics, they must be assembled in an array for possible UIImageView animation NSInteger picCount = [imagesDataSource count]; if(picCount > 1) // 1 image is assumed to be the pic already displayed { // Build image array NSMutableArray *tempPicArray = [[NSMutableArray alloc] init]; // Temp space to hold images while building for(int i = 0; i < picCount; i++) { // Get Nr from only article in detailDataSource & pic name (Small) from each item in imagesDataSource NSString *picAddress = [NSString stringWithFormat:@"http://some.url.com/shopdata/image/article/%@/%@", [[detailDataSource objectAtIndex:0] objectForKey:@"Nr"], [[imagesDataSource objectAtIndex:i] objectForKey:@"Small"]]; NSURL *picURL = [NSURL URLWithString:picAddress]; NSData *picData = [NSData dataWithContentsOfURL:picURL]; [tempPicArray addObject:[UIImage imageWithData:picData]]; } imagesArray = [tempPicArray copy]; // copy makes immutable copy of array [tempPicArray release]; currentPicIndex = 0; // Assume first pic is pic already being shown } else imagesArray = nil; // No need for a needless pic array // Remove please wait message [pleaseWaitViewControllerObject.view removeFromSuperview]; } I put in tons of NSLog lines to keep track of what was going on & self.imagesDataSource is populated with the returned array but when the parser object is released self.imagesDataSource becomes empty. I thought self.imagesDataSource = [ImagesParserObject.returnedArray copy]; is supposed to make an independant object, like as if it was alloc, init'ed, so that self.imagesDataSource is not just a pointer to the parser's array but is it's own array. So why does the release of the parser object clear the copy of the array. (I checked & double checked that it's not something overwriting self.imagesDataSource, commenting out [imagesParserObject release] consistently fixes the problem) Also, I have exactly the same problem with self.detailDataSource which is declared & populated in the exact same way as self.imagesDataSource I thought that once I call the parser I could release it because the caller no longer needs to refer to it, all further activity is carried out by the parser object through it's delegate method, what am I doing wrong?

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  • Non-linear regression models in PostgreSQL using R

    - by Dave Jarvis
    Background I have climate data (temperature, precipitation, snow depth) for all of Canada between 1900 and 2009. I have written a basic website and the simplest page allows users to choose category and city. They then get back a very simple report (without the parameters and calculations section): The primary purpose of the web application is to provide a simple user interface so that the general public can explore the data in meaningful ways. (A list of numbers is not meaningful to the general public, nor is a website that provides too many inputs.) The secondary purpose of the application is to provide climatologists and other scientists with deeper ways to view the data. (Using too many inputs, of course.) Tool Set The database is PostgreSQL with R (mostly) installed. The reports are written using iReport and generated using JasperReports. Poor Model Choice Currently, a linear regression model is applied against annual averages of daily data. The linear regression model is calculated within a PostgreSQL function as follows: SELECT regr_slope( amount, year_taken ), regr_intercept( amount, year_taken ), corr( amount, year_taken ) FROM temp_regression INTO STRICT slope, intercept, correlation; The results are returned to JasperReports using: SELECT year_taken, amount, year_taken * slope + intercept, slope, intercept, correlation, total_measurements INTO result; JasperReports calls into PostgreSQL using the following parameterized analysis function: SELECT year_taken, amount, measurements, regression_line, slope, intercept, correlation, total_measurements, execute_time FROM climate.analysis( $P{CityId}, $P{Elevation1}, $P{Elevation2}, $P{Radius}, $P{CategoryId}, $P{Year1}, $P{Year2} ) ORDER BY year_taken This is not an optimal solution because it gives the false impression that the climate is changing at a slow, but steady rate. Questions Using functions that take two parameters (e.g., year [X] and amount [Y]), such as PostgreSQL's regr_slope: What is a better regression model to apply? What CPAN-R packages provide such models? (Installable, ideally, using apt-get.) How can the R functions be called within a PostgreSQL function? If no such functions exist: What parameters should I try to obtain for functions that will produce the desired fit? How would you recommend showing the best fit curve? Keep in mind that this is a web app for use by the general public. If the only way to analyse the data is from an R shell, then the purpose has been defeated. (I know this is not the case for most R functions I have looked at so far.) Thank you!

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  • How do you handle EF Data Contexts combined with asp.net custom membership/role providers

    - by KallDrexx
    I can't seem to get my head around how to implement a custom membership provider with Entity Framework data contexts into my asp.net MVC application. I understand how to create a custom membership/role provider by itself (using this as a reference). Here's my current setup: As of now I have a repository factory interface that allows different repository factories to be created (right now I only have a factory for EF repositories and and in memory repositories). The repository factory looks like this: public class EFRepositoryFactory : IRepositoryFactory { private EntitiesContainer _entitiesContext; /// <summary> /// Constructor that generates the necessary object contexts /// </summary> public EFRepositoryFactory() { _entitiesContext = new EntitiesContainer(); } /// <summary> /// Generates a new entity framework repository for the specified entity type /// </summary> /// <typeparam name="T">Type of entity to generate a repository for </typeparam> /// <returns>Returns an EFRepository</returns> public IRepository<T> GenerateRepository<T>() where T : class { return new EFRepository<T>(_entitiesContext); } } Controllers are passed an EF repository factory via castle Windsor. The controller then creates all the service/business layer objects it requires and passes in the repository factory into it. This means that all service objects are using the same EF data contexts and I do not have to worry about objects being used in more than one data context (which of course is not allowed and causes an exception). As of right now I am trying to decide how to generate my user and authorization service layers, and have run against a design roadblock. The User/Authization service will be a central class that handles the logic for logging in, changing user details, managing roles and determining what users have access to what. The problem is, using the current methodology the asp.net mvc controllers will initialize it's own EF repository factory via Windsor and the asp.net membership/role provider will have to initialize it's own EF repository factory. This means that each part of the site will then have it's own data context. This seems to mean that if asp.net authenticates a user, that user's object will be in the membership provider's data context and thus if I try to retrieve that user object in the service layer (say to change the user's name) I will get a duplication exception. I thought of making the repository factory class a singleton, but I don't see a way for that to work with castle Windsor. How do other people handle asp.net custom providers in a MVC (or any n-tier) architecture without having object duplication issues?

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  • Blackberry Player, custom data source

    - by Alex
    Hello I must create a custom media player within the application with support for mp3 and wav files. I read in the documentation i cant seek or get the media file duration without a custom datasoruce. I checked the demo in the JDE 4.6 but i have still problems... I cant get the duration, it return much more then the expected so i`m sure i screwed up something while i modified the code to read the mp3 file locally from the filesystem. Somebody can help me what i did wrong ? (I can hear the mp3, so the player plays it correctly from start to end) I must support OSs = 4.6. Thank You Here is my modified datasource LimitedRateStreaminSource.java * Copyright © 1998-2009 Research In Motion Ltd. Note: For the sake of simplicity, this sample application may not leverage resource bundles and resource strings. However, it is STRONGLY recommended that application developers make use of the localization features available within the BlackBerry development platform to ensure a seamless application experience across a variety of languages and geographies. For more information on localizing your application, please refer to the BlackBerry Java Development Environment Development Guide associated with this release. */ package com.halcyon.tawkwidget.model; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import javax.microedition.io.Connector; import javax.microedition.io.file.FileConnection; import javax.microedition.media.Control; import javax.microedition.media.protocol.ContentDescriptor; import javax.microedition.media.protocol.DataSource; import javax.microedition.media.protocol.SourceStream; import net.rim.device.api.io.SharedInputStream; /** * The data source used by the BufferedPlayback's media player. / public final class LimitedRateStreamingSource extends DataSource { /* The max size to be read from the stream at one time. */ private static final int READ_CHUNK = 512; // bytes /** A reference to the field which displays the load status. */ //private TextField _loadStatusField; /** A reference to the field which displays the player status. */ //private TextField _playStatusField; /** * The minimum number of bytes that must be buffered before the media file * will begin playing. */ private int _startBuffer = 200000; /** The maximum size (in bytes) of a single read. */ private int _readLimit = 32000; /** * The minimum forward byte buffer which must be maintained in order for * the video to keep playing. If the forward buffer falls below this * number, the playback will pause until the buffer increases. */ private int _pauseBytes = 64000; /** * The minimum forward byte buffer required to resume * playback after a pause. */ private int _resumeBytes = 128000; /** The stream connection over which media content is passed. */ //private ContentConnection _contentConnection; private FileConnection _fileConnection; /** An input stream shared between several readers. */ private SharedInputStream _readAhead; /** A stream to the buffered resource. */ private LimitedRateSourceStream _feedToPlayer; /** The MIME type of the remote media file. */ private String _forcedContentType; /** A counter for the total number of buffered bytes */ private volatile int _totalRead; /** A flag used to tell the connection thread to stop */ private volatile boolean _stop; /** * A flag used to indicate that the initial buffering is complete. In * other words, that the current buffer is larger than the defined start * buffer size. */ private volatile boolean _bufferingComplete; /** A flag used to indicate that the remote file download is complete. */ private volatile boolean _downloadComplete; /** The thread which retrieves the remote media file. */ private ConnectionThread _loaderThread; /** The local save file into which the remote file is written. */ private FileConnection _saveFile; /** A stream for the local save file. */ private OutputStream _saveStream; /** * Constructor. * @param locator The locator that describes the DataSource. */ public LimitedRateStreamingSource(String locator) { super(locator); } /** * Open a connection to the locator. * @throws IOException */ public void connect() throws IOException { //Open the connection to the remote file. _fileConnection = (FileConnection)Connector.open(getLocator(), Connector.READ); //Cache a reference to the locator. String locator = getLocator(); //Report status. System.out.println("Loading: " + locator); //System.out.println("Size: " + _contentConnection.getLength()); System.out.println("Size: " + _fileConnection.totalSize()); //The name of the remote file begins after the last forward slash. int filenameStart = locator.lastIndexOf('/'); //The file name ends at the first instance of a semicolon. int paramStart = locator.indexOf(';'); //If there is no semicolon, the file name ends at the end of the line. if (paramStart < 0) { paramStart = locator.length(); } //Extract the file name. String filename = locator.substring(filenameStart, paramStart); System.out.println("Filename: " + filename); //Open a local save file with the same name as the remote file. _saveFile = (FileConnection) Connector.open("file:///SDCard/blackberry/music" + filename, Connector.READ_WRITE); //If the file doesn't already exist, create it. if (!_saveFile.exists()) { _saveFile.create(); } System.out.println("---------- 1"); //Open the file for writing. _saveFile.setReadable(true); //Open a shared input stream to the local save file to //allow many simultaneous readers. SharedInputStream fileStream = SharedInputStream.getSharedInputStream(_saveFile.openInputStream()); //Begin reading at the beginning of the file. fileStream.setCurrentPosition(0); System.out.println("---------- 2"); //If the local file is smaller than the remote file... if (_saveFile.fileSize() < _fileConnection.totalSize()) { System.out.println("---------- 3"); //Did not get the entire file, set the system to try again. _saveFile.setWritable(true); System.out.println("---------- 4"); //A non-null save stream is used as a flag later to indicate that //the file download was incomplete. _saveStream = _saveFile.openOutputStream(); System.out.println("---------- 5"); //Use a new shared input stream for buffered reading. _readAhead = SharedInputStream.getSharedInputStream(_fileConnection.openInputStream()); System.out.println("---------- 6"); } else { //The download is complete. System.out.println("---------- 7"); _downloadComplete = true; //We can use the initial input stream to read the buffered media. _readAhead = fileStream; System.out.println("---------- 8"); //We can close the remote connection. _fileConnection.close(); System.out.println("---------- 9"); } if (_forcedContentType != null) { //Use the user-defined content type if it is set. System.out.println("---------- 10"); _feedToPlayer = new LimitedRateSourceStream(_readAhead, _forcedContentType); System.out.println("---------- 11"); } else { System.out.println("---------- 12"); //Otherwise, use the MIME types of the remote file. // _feedToPlayer = new LimitedRateSourceStream(_readAhead, _fileConnection)); } System.out.println("---------- 13"); } /** * Destroy and close all existing connections. */ public void disconnect() { try { if (_saveStream != null) { //Destroy the stream to the local save file. _saveStream.close(); _saveStream = null; } //Close the local save file. _saveFile.close(); if (_readAhead != null) { //Close the reader stream. _readAhead.close(); _readAhead = null; } //Close the remote file connection. _fileConnection.close(); //Close the stream to the player. _feedToPlayer.close(); } catch (Exception e) { System.err.println(e.getMessage()); } } /** * Returns the content type of the remote file. * @return The content type of the remote file. */ public String getContentType() { return _feedToPlayer.getContentDescriptor().getContentType(); } /** * Returns a stream to the buffered resource. * @return A stream to the buffered resource. */ public SourceStream[] getStreams() { return new SourceStream[] { _feedToPlayer }; } /** * Starts the connection thread used to download the remote file. */ public void start() throws IOException { //If the save stream is null, we have already completely downloaded //the file. if (_saveStream != null) { //Open the connection thread to finish downloading the file. _loaderThread = new ConnectionThread(); _loaderThread.start(); } } /** * Stop the connection thread. */ public void stop() throws IOException { //Set the boolean flag to stop the thread. _stop = true; } /** * @see javax.microedition.media.Controllable#getControl(String) */ public Control getControl(String controlType) { // No implemented Controls. return null; } /** * @see javax.microedition.media.Controllable#getControls() */ public Control[] getControls() { // No implemented Controls. return null; } /** * Force the lower level stream to a given content type. Must be called * before the connect function in order to work. * @param contentType The content type to use. */ public void setContentType(String contentType) { _forcedContentType = contentType; } /** * A stream to the buffered media resource. */ private final class LimitedRateSourceStream implements SourceStream { /** A stream to the local copy of the remote resource. */ private SharedInputStream _baseSharedStream; /** Describes the content type of the media file. */ private ContentDescriptor _contentDescriptor; /** * Constructor. Creates a LimitedRateSourceStream from * the given InputStream. * @param inputStream The input stream used to create a new reader. * @param contentType The content type of the remote file. */ LimitedRateSourceStream(InputStream inputStream, String contentType) { System.out.println("[LimitedRateSoruceStream]---------- 1"); _baseSharedStream = SharedInputStream.getSharedInputStream(inputStream); System.out.println("[LimitedRateSoruceStream]---------- 2"); _contentDescriptor = new ContentDescriptor(contentType); System.out.println("[LimitedRateSoruceStream]---------- 3"); } /** * Returns the content descriptor for this stream. * @return The content descriptor for this stream. */ public ContentDescriptor getContentDescriptor() { return _contentDescriptor; } /** * Returns the length provided by the connection. * @return long The length provided by the connection. */ public long getContentLength() { return _fileConnection.totalSize(); } /** * Returns the seek type of the stream. */ public int getSeekType() { return RANDOM_ACCESSIBLE; //return SEEKABLE_TO_START; } /** * Returns the maximum size (in bytes) of a single read. */ public int getTransferSize() { return _readLimit; } /** * Writes bytes from the buffer into a byte array for playback. * @param bytes The buffer into which the data is read. * @param off The start offset in array b at which the data is written. * @param len The maximum number of bytes to read. * @return the total number of bytes read into the buffer, or -1 if * there is no more data because the end of the stream has been reached. * @throws IOException */ public int read(byte[] bytes, int off, int len) throws IOException { System.out.println("[LimitedRateSoruceStream]---------- 5"); System.out.println("Read Request for: " + len + " bytes"); //Limit bytes read to our readLimit. int readLength = len; System.out.println("[LimitedRateSoruceStream]---------- 6"); if (readLength > getReadLimit()) { readLength = getReadLimit(); } //The number of available byes in the buffer. int available; //A boolean flag indicating that the thread should pause //until the buffer has increased sufficiently. boolean paused = false; System.out.println("[LimitedRateSoruceStream]---------- 7"); for (;;) { available = _baseSharedStream.available(); System.out.println("[LimitedRateSoruceStream]---------- 8"); if (_downloadComplete) { //Ignore all restrictions if downloading is complete. System.out.println("Complete, Reading: " + len + " - Available: " + available); return _baseSharedStream.read(bytes, off, len); } else if(_bufferingComplete) { if (paused && available > getResumeBytes()) { //If the video is paused due to buffering, but the //number of available byes is sufficiently high, //resume playback of the media. System.out.println("Resuming - Available: " + available); paused = false; return _baseSharedStream.read(bytes, off, readLength); } else if(!paused && (available > getPauseBytes() || available > readLength)) { //We have enough information for this media playback. if (available < getPauseBytes()) { //If the buffer is now insufficient, set the //pause flag. paused = true; } System.out.println("Reading: " + readLength + " - Available: " + available); return _baseSharedStream.read(bytes, off, readLength); } else if(!paused) { //Set pause until loaded enough to resume. paused = true; } } else { //We are not ready to start yet, try sleeping to allow the //buffer to increase. try { Thread.sleep(500); } catch (Exception e) { System.err.println(e.getMessage()); } } } } /** * @see javax.microedition.media.protocol.SourceStream#seek(long) */ public long seek(long where) throws IOException { _baseSharedStream.setCurrentPosition((int) where); return _baseSharedStream.getCurrentPosition(); } /** * @see javax.microedition.media.protocol.SourceStream#tell() */ public long tell() { return _baseSharedStream.getCurrentPosition(); } /** * Close the stream. * @throws IOException */ void close() throws IOException { _baseSharedStream.close(); } /** * @see javax.microedition.media.Controllable#getControl(String) */ public Control getControl(String controlType) { // No implemented controls. return null; } /** * @see javax.microedition.media.Controllable#getControls() */ public Control[] getControls() { // No implemented controls. return null; } } /** * A thread which downloads the remote file and writes it to the local file. */ private final class ConnectionThread extends Thread { /** * Download the remote media file, then write it to the local * file. * @see java.lang.Thread#run() */ public void run() { try { byte[] data = new byte[READ_CHUNK]; int len = 0; //Until we reach the end of the file. while (-1 != (len = _readAhead.read(data))) { _totalRead += len; if (!_bufferingComplete && _totalRead > getStartBuffer()) { //We have enough of a buffer to begin playback. _bufferingComplete = true; System.out.println("Initial Buffering Complete"); } if (_stop) { //Stop reading. return; } } System.out.println("Downloading Complete"); System.out.println("Total Read: " + _totalRead); //If the downloaded data is not the same size //as the remote file, something is wrong. if (_totalRead != _fileConnection.totalSize()) { System.err.println("* Unable to Download entire file *"); } _downloadComplete = true; _readAhead.setCurrentPosition(0); //Write downloaded data to the local file. while (-1 != (len = _readAhead.read(data))) { _saveStream.write(data); } } catch (Exception e) { System.err.println(e.toString()); } } } /** * Gets the minimum forward byte buffer which must be maintained in * order for the video to keep playing. * @return The pause byte buffer. */ int getPauseBytes() { return _pauseBytes; } /** * Sets the minimum forward buffer which must be maintained in order * for the video to keep playing. * @param pauseBytes The new pause byte buffer. */ void setPauseBytes(int pauseBytes) { _pauseBytes = pauseBytes; } /** * Gets the maximum size (in bytes) of a single read. * @return The maximum size (in bytes) of a single read. */ int getReadLimit() { return _readLimit; } /** * Sets the maximum size (in bytes) of a single read. * @param readLimit The new maximum size (in bytes) of a single read. */ void setReadLimit(int readLimit) { _readLimit = readLimit; } /** * Gets the minimum forward byte buffer required to resume * playback after a pause. * @return The resume byte buffer. */ int getResumeBytes() { return _resumeBytes; } /** * Sets the minimum forward byte buffer required to resume * playback after a pause. * @param resumeBytes The new resume byte buffer. */ void setResumeBytes(int resumeBytes) { _resumeBytes = resumeBytes; } /** * Gets the minimum number of bytes that must be buffered before the * media file will begin playing. * @return The start byte buffer. */ int getStartBuffer() { return _startBuffer; } /** * Sets the minimum number of bytes that must be buffered before the * media file will begin playing. * @param startBuffer The new start byte buffer. */ void setStartBuffer(int startBuffer) { _startBuffer = startBuffer; } } And in this way i use it: LimitedRateStreamingSource source = new LimitedRateStreamingSource("file:///SDCard/music3.mp3"); source.setContentType("audio/mpeg"); mediaPlayer = javax.microedition.media.Manager.createPlayer(source); mediaPlayer.addPlayerListener(this); mediaPlayer.realize(); mediaPlayer.prefetch(); After start i use mediaPlayer.getDuration it returns lets say around 24:22 (the inbuild media player in the blackberry say the file length is 4:05) I tried to get the duration in the listener and there unfortunatly returned around 64 minutes, so im sure something is not good inside the datasoruce....

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  • Excel string manipulation to check data consistency

    - by chefsmart
    Background information: - There are nearly 7000 individuals and there is data about their performances in one, two or three tests. Every individual has taken the 1st test (let's call it Test M). Some of those who have taken Test M have also taken Test I, and some of those who have taken Test I have also taken Test B. For the first two tests (M and I), students can score grades I, II, or III. Depending on the grades they are awarded points -- 3 for grade I, 2 for II, 1 for III. The last Test B is just a pass or a fail result with no grades. Those passing this test get 1 point, with no points for failure. (Well actually, grades are awarded, but all grades are given a common 1 point). An amateur has entered data to represent these students and their grades in an Excel file. Problem is, this person has done the worst thing possible - he has developed his own notation and entered all test information in a single cell --- and made my life hell. The file originally had two text columns, one for individual's id, and the second for test info, if one could call it that. It's horrible, I know, and I am suffering. In the image, if you see "M-II-2 I-III-1" it means the person got grade II in Test M for 2 points and grade III in Test I for 1 point. Some have taken only one test, some two, and some three. When the file came to me for processing and analyzing the performance of students, I sent it back with instructions to insert 3 additional columns with only the grades for the three tests. The file now looks as follows. Columns C and D represent grades I, II, and III using 1,2 and 3 respectively. Column C is for Test M, column D for Test I. Column E says BA (B Achieved!) if the individual has passed Test B. Now that you have the above information, let's get to the problem. I don't trust this and want to check whether data in column B matches with data in columns C,D and E. That is, I want to examine the string in column B and find out whether the figures in columns C,D and E are correct. All help is really appreciated. P.S. - I had exported this to MySQL via ODBC and that is why you are seeing those NULLs. I tried doing this in MySQL too, and really will accept a MySQL or an Excel solution, I don't have a preference. Edit : - See file with sample data

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  • Pruning data for better viewing on loglog graph - Matlab

    - by Geodesic
    Hi Guys, just wondering if anyone has any ideas about an issue I'm having. I have a fair amount of data that needs to be displayed on one graph. Two theoretical lines that are bold and solid are displayed on top, then 10 experimental data sets that converge to these lines are graphed, each using a different identifier (eg the + or o or a square etc). These graphs are on a log scale that goes up to 1e6. The first few decades of the graph (< 1e3) look fine, but as all the datasets converge ( 1e3) it's really difficult to see what data is what. There's over 1000 data points points per decade which I can prune linearly to an extent, but if I do this too much the lower end of the graph will suffer in resolution. What I'd like to do is prune logarithmically, strongest at the high end, working back to 0. My question is: how can I get a logarithmically scaled index vector rather than a linear one? My initial assumption was that as my data is lenear I could just use a linear index to prune, which lead to something like this (but for all decades): //%grab indicies per decade ind12 = find(y >= 1e1 & y <= 1e2); indlow = find(y < 1e2); indhigh = find(y > 1e4); ind23 = find(y >+ 1e2 & y <= 1e3); ind34 = find(y >+ 1e3 & y <= 1e4); //%We want ind12 indexes in this decade, find spacing tot23 = round(length(ind23)/length(ind12)); tot34 = round(length(ind34)/length(ind12)); //%grab ones to keep ind23keep = ind23(1):tot23:ind23(end); ind34keep = ind34(1):tot34:ind34(end); indnew = [indlow' ind23keep ind34keep indhigh']; loglog(x(indnew), y(indnew)); But this causes the prune to behave in a jumpy fashion obviously. Each decade has the number of points that I'd like, but as it's a linear distribution, the points tend to be clumped at the high end of the decade on the log scale. Any ideas on how I can do this?

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  • C++ Class Templates (Queue of a class)

    - by Dalton Conley
    Ok, so I have my basic linked Queue class with basic functions such as front(), empty() etc.. and I have transformed it into a template. Now, I also have a class called Student. Which holds 2 values: Student name and Student Id. I can print out a student with the following code.. Student me("My Name", 2); cout << me << endl; Here is my display function for student: void display(ostream &out) const { out << "Student Name: " << name << "\tStudent Id: " << id << "\tAddress: " << this << endl; } Now it works fine, you can see the basic output. Now I'm declaring a queue like so.. Queue<Student> qstu; Storing data in this queue is fine, I can add new values and such.. now what I'm trying to do is print out my whole queue of students with: cout << qstu << endl; But its simply returning an address.. here is my display function for queues. void display(ostream & out) const { NodePointer ptr; ptr = myFront; while(ptr != NULL) { out << ptr->data << " "; ptr = ptr->next; } out << endl; } Now, based on this, I assume ptr-data is a Student type and I would assume this would work, but it doesn't. Is there something I'm missing? Also, when I Try: ptr->data.display(out); (Making the assumtion ptr-data is of type student, it does not work which tells me I am doing something wrong. Help on this would be much appreciated!

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  • Angularjs togglecheck error(not working as intended) with prechecked data

    - by crozzfire
    I have this plunker where i have a button that opens a bootstrap modal dialog box. I the modal, when a course is selected(checked) from this list, it adds 3 to the $scope.planned and also increases the progress bar accordingly. Similarly it also reduces in the same way when a checkbox is unchecked. This is the function that does the above: $scope.toggleCheck = function (course) { //debugger var x = $scope.checkcoursefunction($scope.selectedCourses, course); if(x==true){ $scope.selectedCourses.splice($scope.selectedCourses.indexOf(course), 1); $scope.planned -= 3; } else{ if ($scope.selectedCourses.indexOf(course) === -1){ $scope.selectedCourses.push(course); $scope.planned += 3; } else { $scope.selectedCourses.splice($scope.selectedCourses.indexOf(course), 1); $scope.planned -= 3; } } $scope.getPercentage(); }; I have 2 services from where the controller fetches its data named Requirements and Planned Services. The table in the modal has a list of the requirements service data. I also have a function named checkplanneddetails() that checks if an item from this data is present in the requirements data. If present, they come in the table pre-checked. This is the function that checks: $scope.checkplanneddetails = function(course){ $scope.coursedetail = course; $scope.requirementcoursename = ($scope.coursedetail.course.subject).concat("-",$scope.coursedetail.course.course_no); for(var k = 0; k < $scope.planneddetails.length; k++){ if($scope.requirementcoursename==$scope.planneddetails[k].course_name){ $scope.selectedCourses.push(course); return true; } } return false; }; $scope.checkcoursefunction = function(arr,obj){ return (arr.indexOf(obj) != -1); } This works fine with bringing the data as checked. But the togglecheck() function does not work as they are supposed to with these checked details(they work in reverse). It always returns true(for var x in togglecheck) even after the splice function. Am i splicing the course correctly?

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  • Summarising (permanently) data in a SQL table

    - by Cylindric
    Geetings, Stackers. I have a huge number of data-points in a SQL table, and I want to summarise them in a way reminiscent of RRD. Assuming a table such as ID | ENTITY_ID | SCORE_DATE | SCORE | SOME_OTHER_DATA ----+-----------+------------+-------+----------------- 1 | A00000001 | 01/01/2010 | 100 | some data 2 | A00000002 | 01/01/2010 | 105 | more data 3 | A00000003 | 01/01/2010 | 104 | various text ... | ......... | .......... | ..... | ... ... | A00009999 | 01/01/2010 | 101 | ... | A00000001 | 02/01/2010 | 104 | ... | A00000002 | 02/01/2010 | 119 | ... | A00000003 | 02/01/2010 | 119 | ... | ......... | .......... | ..... | ... | A00009999 | 02/01/2010 | 101 | arbitrary data ... | ......... | .......... | ..... | ... ... | A00000001 | 01/02/2010 | 104 | ... | A00000002 | 01/02/2010 | 119 | ... | A00000003 | 01/01/2010 | 119 | I want to end up with one record per entity, per month: ID | ENTITY_ID | SCORE_DATE | SCORE | ----+-----------+------------+-------+ ... | A00000001 | 01/01/2010 | 100 | ... | A00000002 | 01/01/2010 | 105 | ... | A00000003 | 01/01/2010 | 104 | ... | A00000001 | 01/02/2010 | 100 | ... | A00000002 | 01/02/2010 | 105 | ... | A00000003 | 01/02/2010 | 104 | (I Don't care about the SOME_OTHER_DATA - I'll pick something - either the first or last record probably.) What's an easy way of doing this on a regular basis, so that anything in the last calendar month is summarised in this way? At the moment my plan is kind of: For each EntityID For each month Find average score for all records in given month Update first record with results of previous step Delete all records that aren't the first I can't think of a neat way of doing it though, that doesn't involve lots of updates and iteration. This can either be done in a SQL Stored Procedure, or it can be incorporated into the .Net app that's generating this data, so the solution doesn't really need to be "one big SQL script", but can be :) (SQL-2005)

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  • Save HashMap data into SQLite

    - by Matthew
    I'm Trying to save data from Json into SQLite. For now I keep the data from Json into HashMap. I already search it, and there's said use the ContentValues. But I still don't get it how to use it. I try looking at this question save data to SQLite from json object using Hashmap in Android, but it doesn't help a lot. Is there any option that I can use to save the data from HashMap into SQLite? Here's My code. MainHellobali.java // Hashmap for ListView ArrayList<HashMap<String, String>> all_itemList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main_helloballi); all_itemList = new ArrayList<HashMap<String, String>>(); // Calling async task to get json new getAllItem().execute(); } private class getAllItem extends AsyncTask<Void, Void, Void> { @Override protected Void doInBackground(Void... arg0) { // Creating service handler class instance ServiceHandler sh = new ServiceHandler(); // Making a request to url and getting response String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET); Log.d("Response: ", "> " + jsonStr); if (jsonStr != null) { try { all_item = new JSONArray(jsonStr); // looping through All Contacts for (int i = 0; i < all_item.length(); i++) { JSONObject c = all_item.getJSONObject(i); String item_id = c.getString(TAG_ITEM_ID); String category_name = c.getString(TAG_CATEGORY_NAME); String item_name = c.getString(TAG_ITEM_NAME); // tmp hashmap for single contact HashMap<String, String> allItem = new HashMap<String, String>(); // adding each child node to HashMap key => value allItem.put(TAG_ITEM_ID, item_id); allItem.put(TAG_CATEGORY_NAME, category_name); allItem.put(TAG_ITEM_NAME, item_name); // adding contact to contact list all_itemList.add(allItem); } } catch (JSONException e) { e.printStackTrace(); } } else { Log.e("ServiceHandler", "Couldn't get any data from the url"); } return null; } } I have DatabasehHandler.java and AllItem.java too. I can put it in here if its necessary. Thanks before ** Add Edited Code ** // looping through All Contacts for (int i = 0; i < all_item.length(); i++) { JSONObject c = all_item.getJSONObject(i); String item_id = c.getString(TAG_ITEM_ID); String category_name = c.getString(TAG_CATEGORY_NAME); String item_name = c.getString(TAG_ITEM_NAME); DatabaseHandler databaseHandler = new DatabaseHandler(this); //error here "The Constructor DatabaseHandler(MainHellobali.getAllItem) is undefined }

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  • Is there a recommended approach to handle saving data in response to within-site navigation without

    - by Carvell Fenton
    Hello all, Preamble to scope my question: I have a web app (or site, this is an internal LAN site) that uses jQuery and AJAX extensively to dynamically load the content section of the UI in the browser. A user navigates the app using a navigation menu. Clicking an item in the navigation menu makes an AJAX call to php, and php then returns the content that is used to populate the central content section. One of the pages served back by php has a table form, set up like a spreadsheet, that the user enters values into. This table is always kept in sync with data in the database. So, when the table is created, is it populated with the relevant database data. Then when the user makes a change in a "cell", that change immediately is written back to the database so the table and database are always in sync. This approach was take to reassure users that the data they entered has been saved (long story...), and to alleviate them from having to click a save button of some kind. So, this always in sync idea is great, except that a user can enter a value in a cell, not take focus out of the cell, and then take any number of actions that would cause that last value to be lost: e.g. navigate to another section of the site via the navigation menu, log out of the app, close the browser, etc. End of preamble, on to the issue: I initially thought that wasn't a problem, because I would just track what data was "dirty" or not saved, and then in the onunload event I would do a final write to the database. Herein lies the rub: because of my clever (or not so clever, not sure) use of AJAX and dynamically loading the content section, the user never actually leaves the original url, or page, when the above actions are taken, with the exception of closing the browser. Therefore, the onunload event does not fire, and I am back to losing the last data again. My question, is there a recommended way to handle figuring out if a person is navigating away from a "section" of your app when content is dynamically loaded this way? I can come up with a solution I think, that involves globals and tracking the currently viewed page, but I thought I would check if there might be a more elegant solution out there, or a change I could make in my design, that would make this work. Thanks in advance as always!

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  • jQuery Form plugin - no data from file upload?

    - by pojo
    I've been struggling a bit with the jQuery Form plugin. I want to create a file upload form that posts the data (JSON, from the chosen file) into a REST service exposed by a servlet. The URL for the POST is calculated from what the user chooses in a SELECT dropdown. When the upload is complete, I want to notify the user immediately, AJAX-style. The problem is that the POST header has a Content-Length of 0 and contains no data. I would appreciate any help! <html> <head> <script type="text/javascript" src="js/jquery-1.4.2.min.js">/* ppp */</script> <script type="text/javascript" src="js/jquery.form.js">/* ppp */</script> <script type="text/javascript"> function cb_beforesubmit (arr, $form, options) { // This should override the form's action attribute options.url = "/rest/services/" + $('#selectedaction')[0].value; return true; } function cb_success (rt, st, xhr, wf) { $('#response').html(rt + '<br>' + st + '<br>' + xhr); } $(document).ready(function () { var options = { beforeSubmit: cb_beforesubmit, success: cb_success, dataType: 'json', contentType: 'application/json', method: 'POST', }; $('#myform').ajaxForm(options); $.getJSON('/rest/services', function (data, ts) { for (var property in data) { if (typeof property == 'string') { $('#selectedaction').append('<option>' + property + '</option>'); } } }); }); </script> </head> <body> <form id="myform" action="/rest/services/foo1" method="POST" enctype="multipart/form-data"> <!-- The form does not seem to submit at all if I don't set action to a default value? !--> <select id="selectedaction"> <script type="text/javascript"> </script> </select> <input type="file" value="Choose"/> <input type="submit" value="Submit" /> </form> <div id="response"> </div> </body> </html>

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  • Two collections and a for loop. (Urgent help needed) Checking an object variable against an inputted

    - by Elliott
    Hi there, I'm relatively new to java, I'm certain the error is trivial. But can't for the life of me spot it. I have an end of term exam on monday and currently trying to get to grips with past papers! Anyway heregoes, in another method (ALGO_1) I search over elements of and check the value H_NAME equals a value entered in the main. When I attempt to run the code I get a null pointer exception, also upon trying to print (with System.out.println etc) the H_NAME value after each for loop in the snippet I also get a null statement returned to me. I am fairly certain that the collection is simply not storing the data gathered up by the Scanner. But then again when I check the collection size with size() it is about the right size. Either way I'm pretty lost and would appreciate the help. Main questions I guess to ask are: from the readBackground method is the data.add in the wrong place? is the snippet simply structured wrongly? oh and another point when I use System.out.println to check the Background object values name, starttime, increment etc they print out fine. Thanks in advance.(PS im guessing the formatting is terrible, apologies.) snippet of code: for(Hydro hd: hydros){ System.out.println(hd.H_NAME); for(Background back : backgs){ System.out.println(back.H_NAME); if(back.H_NAME.equals(hydroName)){ //get error here public static Collection<Background> readBackground(String url) throws IOException { URL u = new URL(url); InputStream is = u.openStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader b = new BufferedReader(isr); String line =""; Vector<Background> data = new Vector<Background>(); while((line = b.readLine())!= null){ Scanner s = new Scanner(line); String name = s.next(); double starttime = Double.parseDouble(s.next()); double increment = Double.parseDouble(s.next()); double sum = 0; double p = 0; double nterms = 0; while((s.hasNextDouble())){ p = Double.parseDouble(s.next()); nterms++; sum += p; } double pbmean = sum/nterms; Background SAMP = new Background(name, starttime, increment, pbmean); data.add(SAMP); } return data; } Edit/Delete Message

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  • Create lags with a for-loop in R

    - by cptn
    I've got a data.frame with stock data of several companies (here it's only two). I want 10 additional columns in my stock data.frame df with lagged dates (from -5 days to +5 days) for both companies in my event data.frame. I'm using a for loop which is probably not the best solution, but it works partially. DATE <- c("01.01.2000","02.01.2000","03.01.2000","06.01.2000","07.01.2000","09.01.2000","10.01.2000","01.01.2000","02.01.2000","04.01.2000","06.01.2000","07.01.2000","09.01.2000","10.01.2000") RET <- c(-2.0,1.1,3,1.4,-0.2, 0.6, 0.1, -0.21, -1.2, 0.9, 0.3, -0.1,0.3,-0.12) COMP <- c("A","A","A","A","A","A","A","B","B","B","B","B","B","B") df <- data.frame(DATE, RET, COMP, stringsAsFactors=F) df # DATE RET COMP # 1 01.01.2000 -2.00 A # 2 02.01.2000 1.10 A # 3 03.01.2000 3.00 A # 4 06.01.2000 1.40 A # 5 07.01.2000 -0.20 A # 6 09.01.2000 0.60 A # 7 10.01.2000 0.10 A # 8 01.01.2000 -0.21 B # 9 02.01.2000 -1.20 B # 10 04.01.2000 0.90 B # 11 06.01.2000 0.30 B # 12 07.01.2000 -0.10 B # 13 09.01.2000 0.30 B # 14 10.01.2000 -0.12 B this loop works fine comp <- as.vector(unique(df$COMP)) mylist <- vector('list', length(comp)) # create lags in DATE for(i in 1:length(comp)) { print(i) comp_i <- comp[i] df_k <- df[df$COMP %in% comp_i, ] # all trading days of one firm df_k <- transform(df_k, DATEm1 = c(NA, head(DATE, -1)), DATEm2 = c(NA, NA, head(DATE, -2)), DATEm3 = c(NA, NA, NA, head(DATE, -3)), DATEm4 = c(NA, NA, NA, NA,head(DATE, -4)), DATEm5 = c(NA, NA, NA, NA, NA, head(DATE, -5)), DATEp1 = c(DATE[-1], NA)) #DATEp2 = c(DATE[-2], NA, NA), #DATEp3 = c(DATE[-3], NA, NA, NA), #DATEp4 = c(DATE[-4], NA, NA, NA, NA), #DATEp5 = c(DATE[-5], NA, NA, NA, NA, NA)) mylist[[i]] = df_k } df1 <- do.call(rbind, mylist) But if I add the lines with DATEp2, DATEp3, DATEp4, DATEp5. the code doesn't work. Can anybody tell me what I'm doing wrong here? Here the code with all the lagged dates. # create lags in DATE for(i in 1:length(comp)) { print(i) comp_i <- comp[i] df_k <- df[df$COMP %in% comp_i, ] # all trading days of one firm df_k <- transform(df_k, DATEm1 = c(NA, head(DATE, -1)), DATEm2 = c(NA, NA, head(DATE, -2)), DATEm3 = c(NA, NA, NA, head(DATE, -3)), DATEm4 = c(NA, NA, NA, NA,head(DATE, -4)), DATEm5 = c(NA, NA, NA, NA, NA, head(DATE, -5)), DATEp1 = c(DATE[-1], NA), DATEp2 = c(DATE[-2], NA, NA), DATEp3 = c(DATE[-3], NA, NA, NA), DATEp4 = c(DATE[-4], NA, NA, NA, NA), DATEp5 = c(DATE[-5], NA, NA, NA, NA, NA)) mylist[[i]] = df_k } df1 <- do.call(rbind, mylist)

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  • RequestFactoryEditorDriver getting edited data after flush

    - by Deanna
    Let me start with I have a solution, but I don't really think it is elegant. So, I am looking for a cleaner way to do this. I have an EntityProxy displayed in a view panel. The view panel is a RequestFactoryEditorDriver only using display mode. The user clicks on a data element and opens a popup editor to edit a data element of the EntityProxy with a few more bits of data than is displayed in the view panel. When the user saves the element I need the view panel to update the display. I ran into a problem because the RequestFactoryEditorDriver of the popup editor flow doesn't let you get to the edited data. The driver uses the passed in context and sends it to the server. The context returned out of flush only allows a Receiver even if you cast it to the type of context you stored in the editor driver in the edit() call. It doesn't appear to send and EntityProxyChanged event either, so I couldn't listen for that and update the display view. The solution I found was to change my domain object persist to return the newly saved entity. Then create the popup editor like this editor.getSaveButtonClickHandler().addClickHandler(createSaveHandler(driver, editor)); // initialize the Driver and edit the given text. driver.initialize(rf, editor); PlayerProfileCtx ctx = rf.playerProfile(); ctx.persist().using(playerProfile).with(driver.getPaths()) .to(new Receiver<PlayerProfileProxy>(){ @Override public void onSuccess(PlayerProfileProxy profile) { editor.hide(); playerProfile = profile; viewDriver.display(playerProfile); } }); driver.edit(playerProfile, ctx); editor.centerAndShow(); Then in the save handler I just fire the context I get from the flush. While this approach works, it doesn't seem right. It would seem I should subscribe to the entitychanged event in the display view and update the entity and the view from there. Also this approach saves the complete entity, not just the changed bits, which will increase bandwidth usage. What I would think should happen, is when you flush the entity it should 'optimistically' update the rf managed version of the entity and fire the entity proxy changed event. Only reverting the entity if something went wrong in the save. The actual save should only send the changed bits. In this way there isn't a need to refetch the whole entity and send that complete data over the wire twice. Is there a better solution?

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  • Getting level values from PCM raw data using Core Audio

    - by John
    I am trying to extract level data from a PCM audio file using core audio. I have gotten as far as (I believe) getting the raw data into a byte array (UInt8) but it is 16 bit PCM data and I am having trouble reading the data out. The input is from the iPhone microphone, which I have set as: [recordSetting setValue:[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey]; [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey]; [recordSetting setValue:[NSNumber numberWithInt:1] forKey:AVNumberOfChannelsKey]; [recordSetting setValue:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey]; [recordSetting setValue:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey]; [recordSetting setValue:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey]; which is obviously 16 bits. I am then trying to just print out a few values to see if they look reasonable for debug purposes below, and they do not look reasonable (many 0's). ExtAudioFileRef inputFile = NULL; ExtAudioFileOpenURL(track.location, &inputFile); AudioStreamBasicDescription inputFileFormat; UInt32 dataSize = (UInt32)sizeof(inputFileFormat); ExtAudioFileGetProperty(inputFile, kExtAudioFileProperty_FileDataFormat, &dataSize, &inputFileFormat); UInt8 *buffer = malloc(BUFFER_SIZE); AudioBufferList bufferList; bufferList.mNumberBuffers = 1; bufferList.mBuffers[0].mNumberChannels = 1; bufferList.mBuffers[0].mData = buffer; //pointer to buffer of audio data bufferList.mBuffers[0].mDataByteSize = BUFFER_SIZE; //number of bytes in the buffer while(true) { UInt32 frameCount = (bufferList.mBuffers[0].mDataByteSize / inputFileFormat.mBytesPerFrame); // Read a chunk of input OSStatus status = ExtAudioFileRead(inputFile, &frameCount, &bufferList); // If no frames were returned, conversion is finished if(0 == frameCount) break; NSLog(@"---"); int16_t *bufferl = &buffer; for(int i=0;i<100;i++){ //const int16_t *bufferl = bufferl[i]; NSLog(@"%d",bufferl[i]); } } Not sure what I am doing wrong, I think it has to do with reading the byte array. Sorry for the long code post...

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  • Codeigniter: Retrieving data on button click with Ajax

    - by OllyTenerife
    I have a simple webpage which generates a random quote from my database upon refreshing the page. I wish to implement some AJAX and JQuery in order to generate quotes via the button rather than having to refresh the page. I have done some research but I am not sure how to implement this in Codeigniter. My current code is below... Page controller: public function index() { $this->load->model('quote_model', '', TRUE); $data['quotes'] = $this->quote_model->getRandom(); $this->load->view('home', $data); } The view: <?php include ('layout/header.php'); ?> <div class="container-fluid"> <div class="row"> <div class="col-md-4 quote-holder"> <img src="application/assets/alan1.jpg" alt="..." class="img-circle img-responsive"> <br> <blockquote class="text-center"> <p><?php echo $quotes[0]['quote']; ?></p> <footer class="text-center"><?php echo $quotes[0]['character_name']; ?> in <cite title="Source Title"><?php echo $quotes[0]['series_name']; ?></cite></footer> </blockquote> <button type="button" class="btn btn-default center-block">Generate quote</button> </div> </div> <?php include ('layout/footer.php'); ?> Here is the function in the model I am retrieving the data from: function getRandom() { $query = $this->db->query(" SELECT * FROM quotes, characters, series WHERE quotes.series_id = series.series_id AND quotes.character_id = characters.character_id ORDER BY rand() LIMIT 1 "); return $query->result_array(); } Should I simply be using something like this? $("button").click(function(){ $.get( "Page/index", function( data ) { //output data to page element... } });

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  • SQL Server 2012 - AlwaysOn

    - by Claus Jandausch
    Ich war nicht nur irritiert, ich war sogar regelrecht schockiert - und für einen kurzen Moment sprachlos (was nur selten der Fall ist). Gerade eben hatte mich jemand gefragt "Wann Oracle denn etwas Vergleichbares wie AlwaysOn bieten würde - und ob überhaupt?" War ich hier im falschen Film gelandet? Ich konnte nicht anders, als meinen Unmut kundzutun und zu erklären, dass die Fragestellung normalerweise anders herum läuft. Zugegeben - es mag vielleicht strittige Punkte geben im Vergleich zwischen Oracle und SQL Server - bei denen nicht unbedingt immer Oracle die Nase vorn haben muss - aber das Thema Clustering für Hochverfügbarkeit (HA), Disaster Recovery (DR) und Skalierbarkeit gehört mit Sicherheit nicht dazu. Dieses Erlebnis hakte ich am Nachgang als Einzelfall ab, der so nie wieder vorkommen würde. Bis ich kurz darauf eines Besseren belehrt wurde und genau die selbe Frage erneut zu hören bekam. Diesmal sogar im Exadata-Umfeld und einem Oracle Stretch Cluster. Einmal ist keinmal, doch zweimal ist einmal zu viel... Getreu diesem alten Motto war mir klar, dass man das so nicht länger stehen lassen konnte. Ich habe keine Ahnung, wie die Microsoft Marketing Abteilung es geschafft hat, unter dem AlwaysOn Brading eine innovative Technologie vermuten zu lassen - aber sie hat ihren Job scheinbar gut gemacht. Doch abgesehen von einem guten Marketing, stellt sich natürlich die Frage, was wirklich dahinter steckt und wie sich das Ganze mit Oracle vergleichen lässt - und ob überhaupt? Damit wären wir wieder bei der ursprünglichen Frage angelangt.  So viel zum Hintergrund dieses Blogbeitrags - von meiner Antwort handelt der restliche Blog. "Windows was the God ..." Um den wahren Unterschied zwischen Oracle und Microsoft verstehen zu können, muss man zunächst das bedeutendste Microsoft Dogma kennen. Es lässt sich schlicht und einfach auf den Punkt bringen: "Alles muss auf Windows basieren." Die Überschrift dieses Absatzes ist kein von mir erfundener Ausspruch, sondern ein Zitat. Konkret stammt es aus einem längeren Artikel von Kurt Eichenwald in der Vanity Fair aus dem August 2012. Er lautet Microsoft's Lost Decade und sei jedem ans Herz gelegt, der die "Microsoft-Maschinerie" unter Steve Ballmer und einige ihrer Kuriositäten besser verstehen möchte. "YOU TALKING TO ME?" Microsoft C.E.O. Steve Ballmer bei seiner Keynote auf der 2012 International Consumer Electronics Show in Las Vegas am 9. Januar   Manche Dinge in diesem Artikel mögen überspitzt dargestellt erscheinen - sind sie aber nicht. Vieles davon kannte ich bereits aus eigener Erfahrung und kann es nur bestätigen. Anderes hat sich mir erst so richtig erschlossen. Insbesondere die folgenden Passagen führten zum Aha-Erlebnis: “Windows was the god—everything had to work with Windows,” said Stone... “Every little thing you want to write has to build off of Windows (or other existing roducts),” one software engineer said. “It can be very confusing, …” Ich habe immer schon darauf hingewiesen, dass in einem SQL Server Failover Cluster die Microsoft Datenbank eigentlich nichts Nenneswertes zum Geschehen beiträgt, sondern sich voll und ganz auf das Windows Betriebssystem verlässt. Deshalb muss man auch die Windows Server Enterprise Edition installieren, soll ein Failover Cluster für den SQL Server eingerichtet werden. Denn hier werden die Cluster Services geliefert - nicht mit dem SQL Server. Er ist nur lediglich ein weiteres Server Produkt, für das Windows in Ausfallszenarien genutzt werden kann - so wie Microsoft Exchange beispielsweise, oder Microsoft SharePoint, oder irgendein anderes Server Produkt das auf Windows gehostet wird. Auch Oracle kann damit genutzt werden. Das Stichwort lautet hier: Oracle Failsafe. Nur - warum sollte man das tun, wenn gleichzeitig eine überlegene Technologie wie die Oracle Real Application Clusters (RAC) zur Verfügung steht, die dann auch keine Windows Enterprise Edition voraussetzen, da Oracle die eigene Clusterware liefert. Welche darüber hinaus für kürzere Failover-Zeiten sorgt, da diese Cluster-Technologie Datenbank-integriert ist und sich nicht auf "Dritte" verlässt. Wenn man sich also schon keine technischen Vorteile mit einem SQL Server Failover Cluster erkauft, sondern zusätzlich noch versteckte Lizenzkosten durch die Lizenzierung der Windows Server Enterprise Edition einhandelt, warum hat Microsoft dann in den vergangenen Jahren seit SQL Server 2000 nicht ebenfalls an einer neuen und innovativen Lösung gearbeitet, die mit Oracle RAC mithalten kann? Entwickler hat Microsoft genügend? Am Geld kann es auch nicht liegen? Lesen Sie einfach noch einmal die beiden obenstehenden Zitate und sie werden den Grund verstehen. Anders lässt es sich ja auch gar nicht mehr erklären, dass AlwaysOn aus zwei unterschiedlichen Technologien besteht, die beide jedoch wiederum auf dem Windows Server Failover Clustering (WSFC) basieren. Denn daraus ergeben sich klare Nachteile - aber dazu später mehr. Um AlwaysOn zu verstehen, sollte man sich zunächst kurz in Erinnerung rufen, was Microsoft bisher an HA/DR (High Availability/Desaster Recovery) Lösungen für SQL Server zur Verfügung gestellt hat. Replikation Basiert auf logischer Replikation und Pubisher/Subscriber Architektur Transactional Replication Merge Replication Snapshot Replication Microsoft's Replikation ist vergleichbar mit Oracle GoldenGate. Oracle GoldenGate stellt jedoch die umfassendere Technologie dar und bietet High Performance. Log Shipping Microsoft's Log Shipping stellt eine einfache Technologie dar, die vergleichbar ist mit Oracle Managed Recovery in Oracle Version 7. Das Log Shipping besitzt folgende Merkmale: Transaction Log Backups werden von Primary nach Secondary/ies geschickt Einarbeitung (z.B. Restore) auf jedem Secondary individuell Optionale dritte Server Instanz (Monitor Server) für Überwachung und Alarm Log Restore Unterbrechung möglich für Read-Only Modus (Secondary) Keine Unterstützung von Automatic Failover Database Mirroring Microsoft's Database Mirroring wurde verfügbar mit SQL Server 2005, sah aus wie Oracle Data Guard in Oracle 9i, war funktional jedoch nicht so umfassend. Für ein HA/DR Paar besteht eine 1:1 Beziehung, um die produktive Datenbank (Principle DB) abzusichern. Auf der Standby Datenbank (Mirrored DB) werden alle Insert-, Update- und Delete-Operationen nachgezogen. Modi Synchron (High-Safety Modus) Asynchron (High-Performance Modus) Automatic Failover Unterstützt im High-Safety Modus (synchron) Witness Server vorausgesetzt     Zur Frage der Kontinuität Es stellt sich die Frage, wie es um diesen Technologien nun im Zusammenhang mit SQL Server 2012 bestellt ist. Unter Fanfaren seinerzeit eingeführt, war Database Mirroring das erklärte Mittel der Wahl. Ich bin kein Produkt Manager bei Microsoft und kann hierzu nur meine Meinung äußern, aber zieht man den SQL AlwaysOn Team Blog heran, so sieht es nicht gut aus für das Database Mirroring - zumindest nicht langfristig. "Does AlwaysOn Availability Group replace Database Mirroring going forward?” “The short answer is we recommend that you migrate from the mirroring configuration or even mirroring and log shipping configuration to using Availability Group. Database Mirroring will still be available in the Denali release but will be phased out over subsequent releases. Log Shipping will continue to be available in future releases.” Damit wären wir endlich beim eigentlichen Thema angelangt. Was ist eine sogenannte Availability Group und was genau hat es mit der vielversprechend klingenden Bezeichnung AlwaysOn auf sich?   SQL Server 2012 - AlwaysOn Zwei HA-Features verstekcne sich hinter dem “AlwaysOn”-Branding. Einmal das AlwaysOn Failover Clustering aka SQL Server Failover Cluster Instances (FCI) - zum Anderen die AlwaysOn Availability Groups. Failover Cluster Instances (FCI) Entspricht ungefähr dem Stretch Cluster Konzept von Oracle Setzt auf Windows Server Failover Clustering (WSFC) auf Bietet HA auf Instanz-Ebene AlwaysOn Availability Groups (Verfügbarkeitsgruppen) Ähnlich der Idee von Consistency Groups, wie in Storage-Level Replikations-Software von z.B. EMC SRDF Abhängigkeiten zu Windows Server Failover Clustering (WSFC) Bietet HA auf Datenbank-Ebene   Hinweis: Verwechseln Sie nicht eine SQL Server Datenbank mit einer Oracle Datenbank. Und auch nicht eine Oracle Instanz mit einer SQL Server Instanz. Die gleichen Begriffe haben hier eine andere Bedeutung - nicht selten ein Grund, weshalb Oracle- und Microsoft DBAs schnell aneinander vorbei reden. Denken Sie bei einer SQL Server Datenbank eher an ein Oracle Schema, das kommt der Sache näher. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema. Wenn Sie die genauen Unterschiede kennen möchten, finden Sie eine detaillierte Beschreibung in meinem Buch "Oracle10g Release 2 für Windows und .NET", erhältich bei Lehmanns, Amazon, etc.   Windows Server Failover Clustering (WSFC) Wie man sieht, basieren beide AlwaysOn Technologien wiederum auf dem Windows Server Failover Clustering (WSFC), um einerseits Hochverfügbarkeit auf Ebene der Instanz zu gewährleisten und andererseits auf der Datenbank-Ebene. Deshalb nun eine kurze Beschreibung der WSFC. Die WSFC sind ein mit dem Windows Betriebssystem geliefertes Infrastruktur-Feature, um HA für Server Anwendungen, wie Microsoft Exchange, SharePoint, SQL Server, etc. zu bieten. So wie jeder andere Cluster, besteht ein WSFC Cluster aus einer Gruppe unabhängiger Server, die zusammenarbeiten, um die Verfügbarkeit einer Applikation oder eines Service zu erhöhen. Falls ein Cluster-Knoten oder -Service ausfällt, kann der auf diesem Knoten bisher gehostete Service automatisch oder manuell auf einen anderen im Cluster verfügbaren Knoten transferriert werden - was allgemein als Failover bekannt ist. Unter SQL Server 2012 verwenden sowohl die AlwaysOn Avalability Groups, als auch die AlwaysOn Failover Cluster Instances die WSFC als Plattformtechnologie, um Komponenten als WSFC Cluster-Ressourcen zu registrieren. Verwandte Ressourcen werden in eine Ressource Group zusammengefasst, die in Abhängigkeit zu anderen WSFC Cluster-Ressourcen gebracht werden kann. Der WSFC Cluster Service kann jetzt die Notwendigkeit zum Neustart der SQL Server Instanz erfassen oder einen automatischen Failover zu einem anderen Server-Knoten im WSFC Cluster auslösen.   Failover Cluster Instances (FCI) Eine SQL Server Failover Cluster Instanz (FCI) ist eine einzelne SQL Server Instanz, die in einem Failover Cluster betrieben wird, der aus mehreren Windows Server Failover Clustering (WSFC) Knoten besteht und so HA (High Availability) auf Ebene der Instanz bietet. Unter Verwendung von Multi-Subnet FCI kann auch Remote DR (Disaster Recovery) unterstützt werden. Eine weitere Option für Remote DR besteht darin, eine unter FCI gehostete Datenbank in einer Availability Group zu betreiben. Hierzu später mehr. FCI und WSFC Basis FCI, das für lokale Hochverfügbarkeit der Instanzen genutzt wird, ähnelt der veralteten Architektur eines kalten Cluster (Aktiv-Passiv). Unter SQL Server 2008 wurde diese Technologie SQL Server 2008 Failover Clustering genannt. Sie nutzte den Windows Server Failover Cluster. In SQL Server 2012 hat Microsoft diese Basistechnologie unter der Bezeichnung AlwaysOn zusammengefasst. Es handelt sich aber nach wie vor um die klassische Aktiv-Passiv-Konfiguration. Der Ablauf im Failover-Fall ist wie folgt: Solange kein Hardware-oder System-Fehler auftritt, werden alle Dirty Pages im Buffer Cache auf Platte geschrieben Alle entsprechenden SQL Server Services (Dienste) in der Ressource Gruppe werden auf dem aktiven Knoten gestoppt Die Ownership der Ressource Gruppe wird auf einen anderen Knoten der FCI transferriert Der neue Owner (Besitzer) der Ressource Gruppe startet seine SQL Server Services (Dienste) Die Connection-Anforderungen einer Client-Applikation werden automatisch auf den neuen aktiven Knoten mit dem selben Virtuellen Network Namen (VNN) umgeleitet Abhängig vom Zeitpunkt des letzten Checkpoints, kann die Anzahl der Dirty Pages im Buffer Cache, die noch auf Platte geschrieben werden müssen, zu unvorhersehbar langen Failover-Zeiten führen. Um diese Anzahl zu drosseln, besitzt der SQL Server 2012 eine neue Fähigkeit, die Indirect Checkpoints genannt wird. Indirect Checkpoints ähnelt dem Fast-Start MTTR Target Feature der Oracle Datenbank, das bereits mit Oracle9i verfügbar war.   SQL Server Multi-Subnet Clustering Ein SQL Server Multi-Subnet Failover Cluster entspricht vom Konzept her einem Oracle RAC Stretch Cluster. Doch dies ist nur auf den ersten Blick der Fall. Im Gegensatz zu RAC ist in einem lokalen SQL Server Failover Cluster jeweils nur ein Knoten aktiv für eine Datenbank. Für die Datenreplikation zwischen geografisch entfernten Sites verlässt sich Microsoft auf 3rd Party Lösungen für das Storage Mirroring.     Die Verbesserung dieses Szenario mit einer SQL Server 2012 Implementierung besteht schlicht darin, dass eine VLAN-Konfiguration (Virtual Local Area Network) nun nicht mehr benötigt wird, so wie dies bisher der Fall war. Das folgende Diagramm stellt dar, wie der Ablauf mit SQL Server 2012 gehandhabt wird. In Site A und Site B wird HA jeweils durch einen lokalen Aktiv-Passiv-Cluster sichergestellt.     Besondere Aufmerksamkeit muss hier der Konfiguration und dem Tuning geschenkt werden, da ansonsten völlig inakzeptable Failover-Zeiten resultieren. Dies liegt darin begründet, weil die Downtime auf Client-Seite nun nicht mehr nur von der reinen Failover-Zeit abhängt, sondern zusätzlich von der Dauer der DNS Replikation zwischen den DNS Servern. (Rufen Sie sich in Erinnerung, dass wir gerade von Multi-Subnet Clustering sprechen). Außerdem ist zu berücksichtigen, wie schnell die Clients die aktualisierten DNS Informationen abfragen. Spezielle Konfigurationen für Node Heartbeat, HostRecordTTL (Host Record Time-to-Live) und Intersite Replication Frequeny für Active Directory Sites und Services werden notwendig. Default TTL für Windows Server 2008 R2: 20 Minuten Empfohlene Einstellung: 1 Minute DNS Update Replication Frequency in Windows Umgebung: 180 Minuten Empfohlene Einstellung: 15 Minuten (minimaler Wert)   Betrachtet man diese Werte, muss man feststellen, dass selbst eine optimale Konfiguration die rigiden SLAs (Service Level Agreements) heutiger geschäftskritischer Anwendungen für HA und DR nicht erfüllen kann. Denn dies impliziert eine auf der Client-Seite erlebte Failover-Zeit von insgesamt 16 Minuten. Hierzu ein Auszug aus der SQL Server 2012 Online Dokumentation: Cons: If a cross-subnet failover occurs, the client recovery time could be 15 minutes or longer, depending on your HostRecordTTL setting and the setting of your cross-site DNS/AD replication schedule.    Wir sind hier an einem Punkt unserer Überlegungen angelangt, an dem sich erklärt, weshalb ich zuvor das "Windows was the God ..." Zitat verwendet habe. Die unbedingte Abhängigkeit zu Windows wird zunehmend zum Problem, da sie die Komplexität einer Microsoft-basierenden Lösung erhöht, anstelle sie zu reduzieren. Und Komplexität ist das Letzte, was sich CIOs heutzutage wünschen.  Zur Ehrenrettung des SQL Server 2012 und AlwaysOn muss man sagen, dass derart lange Failover-Zeiten kein unbedingtes "Muss" darstellen, sondern ein "Kann". Doch auch ein "Kann" kann im unpassenden Moment unvorhersehbare und kostspielige Folgen haben. Die Unabsehbarkeit ist wiederum Ursache vieler an der Implementierung beteiligten Komponenten und deren Abhängigkeiten, wie beispielsweise drei Cluster-Lösungen (zwei von Microsoft, eine 3rd Party Lösung). Wie man die Sache auch dreht und wendet, kommt man an diesem Fakt also nicht vorbei - ganz unabhängig von der Dauer einer Downtime oder Failover-Zeiten. Im Gegensatz zu AlwaysOn und der hier vorgestellten Version eines Stretch-Clusters, vermeidet eine entsprechende Oracle Implementierung eine derartige Komplexität, hervorgerufen duch multiple Abhängigkeiten. Den Unterschied machen Datenbank-integrierte Mechanismen, wie Fast Application Notification (FAN) und Fast Connection Failover (FCF). Für Oracle MAA Konfigurationen (Maximum Availability Architecture) sind Inter-Site Failover-Zeiten im Bereich von Sekunden keine Seltenheit. Wenn Sie dem Link zur Oracle MAA folgen, finden Sie außerdem eine Reihe an Customer Case Studies. Auch dies ist ein wichtiges Unterscheidungsmerkmal zu AlwaysOn, denn die Oracle Technologie hat sich bereits zigfach in höchst kritischen Umgebungen bewährt.   Availability Groups (Verfügbarkeitsgruppen) Die sogenannten Availability Groups (Verfügbarkeitsgruppen) sind - neben FCI - der weitere Baustein von AlwaysOn.   Hinweis: Bevor wir uns näher damit beschäftigen, sollten Sie sich noch einmal ins Gedächtnis rufen, dass eine SQL Server Datenbank nicht die gleiche Bedeutung besitzt, wie eine Oracle Datenbank, sondern eher einem Oracle Schema entspricht. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema.   Eine Verfügbarkeitsgruppe setzt sich zusammen aus einem Set mehrerer Benutzer-Datenbanken, die im Falle eines Failover gemeinsam als Gruppe behandelt werden. Eine Verfügbarkeitsgruppe unterstützt ein Set an primären Datenbanken (primäres Replikat) und einem bis vier Sets von entsprechenden sekundären Datenbanken (sekundäre Replikate).       Es können jedoch nicht alle SQL Server Datenbanken einer AlwaysOn Verfügbarkeitsgruppe zugeordnet werden. Der SQL Server Spezialist Michael Otey zählt in seinem SQL Server Pro Artikel folgende Anforderungen auf: Verfügbarkeitsgruppen müssen mit Benutzer-Datenbanken erstellt werden. System-Datenbanken können nicht verwendet werden Die Datenbanken müssen sich im Read-Write Modus befinden. Read-Only Datenbanken werden nicht unterstützt Die Datenbanken in einer Verfügbarkeitsgruppe müssen Multiuser Datenbanken sein Sie dürfen nicht das AUTO_CLOSE Feature verwenden Sie müssen das Full Recovery Modell nutzen und es muss ein vollständiges Backup vorhanden sein Eine gegebene Datenbank kann sich nur in einer einzigen Verfügbarkeitsgruppe befinden und diese Datenbank düerfen nicht für Database Mirroring konfiguriert sein Microsoft empfiehl außerdem, dass der Verzeichnispfad einer Datenbank auf dem primären und sekundären Server identisch sein sollte Wie man sieht, eignen sich Verfügbarkeitsgruppen nicht, um HA und DR vollständig abzubilden. Die Unterscheidung zwischen der Instanzen-Ebene (FCI) und Datenbank-Ebene (Availability Groups) ist von hoher Bedeutung. Vor kurzem wurde mir gesagt, dass man mit den Verfügbarkeitsgruppen auf Shared Storage verzichten könne und dadurch Kosten spart. So weit so gut ... Man kann natürlich eine Installation rein mit Verfügbarkeitsgruppen und ohne FCI durchführen - aber man sollte sich dann darüber bewusst sein, was man dadurch alles nicht abgesichert hat - und dies wiederum für Desaster Recovery (DR) und SLAs (Service Level Agreements) bedeutet. Kurzum, um die Kombination aus beiden AlwaysOn Produkten und der damit verbundene Komplexität kommt man wohl in der Praxis nicht herum.    Availability Groups und WSFC AlwaysOn hängt von Windows Server Failover Clustering (WSFC) ab, um die aktuellen Rollen der Verfügbarkeitsreplikate einer Verfügbarkeitsgruppe zu überwachen und zu verwalten, und darüber zu entscheiden, wie ein Failover-Ereignis die Verfügbarkeitsreplikate betrifft. Das folgende Diagramm zeigt de Beziehung zwischen Verfügbarkeitsgruppen und WSFC:   Der Verfügbarkeitsmodus ist eine Eigenschaft jedes Verfügbarkeitsreplikats. Synychron und Asynchron können also gemischt werden: Availability Modus (Verfügbarkeitsmodus) Asynchroner Commit-Modus Primäres replikat schließt Transaktionen ohne Warten auf Sekundäres Synchroner Commit-Modus Primäres Replikat wartet auf Commit von sekundärem Replikat Failover Typen Automatic Manual Forced (mit möglichem Datenverlust) Synchroner Commit-Modus Geplanter, manueller Failover ohne Datenverlust Automatischer Failover ohne Datenverlust Asynchroner Commit-Modus Nur Forced, manueller Failover mit möglichem Datenverlust   Der SQL Server kennt keinen separaten Switchover Begriff wie in Oracle Data Guard. Für SQL Server werden alle Role Transitions als Failover bezeichnet. Tatsächlich unterstützt der SQL Server keinen Switchover für asynchrone Verbindungen. Es gibt nur die Form des Forced Failover mit möglichem Datenverlust. Eine ähnliche Fähigkeit wie der Switchover unter Oracle Data Guard ist so nicht gegeben.   SQL Sever FCI mit Availability Groups (Verfügbarkeitsgruppen) Neben den Verfügbarkeitsgruppen kann eine zweite Failover-Ebene eingerichtet werden, indem SQL Server FCI (auf Shared Storage) mit WSFC implementiert wird. Ein Verfügbarkeitesreplikat kann dann auf einer Standalone Instanz gehostet werden, oder einer FCI Instanz. Zum Verständnis: Die Verfügbarkeitsgruppen selbst benötigen kein Shared Storage. Diese Kombination kann verwendet werden für lokale HA auf Ebene der Instanz und DR auf Datenbank-Ebene durch Verfügbarkeitsgruppen. Das folgende Diagramm zeigt dieses Szenario:   Achtung! Hier handelt es sich nicht um ein Pendant zu Oracle RAC plus Data Guard, auch wenn das Bild diesen Eindruck vielleicht vermitteln mag - denn alle sekundären Knoten im FCI sind rein passiv. Es existiert außerdem eine weitere und ernsthafte Einschränkung: SQL Server Failover Cluster Instanzen (FCI) unterstützen nicht das automatische AlwaysOn Failover für Verfügbarkeitsgruppen. Jedes unter FCI gehostete Verfügbarkeitsreplikat kann nur für manuelles Failover konfiguriert werden.   Lesbare Sekundäre Replikate Ein oder mehrere Verfügbarkeitsreplikate in einer Verfügbarkeitsgruppe können für den lesenden Zugriff konfiguriert werden, wenn sie als sekundäres Replikat laufen. Dies ähnelt Oracle Active Data Guard, jedoch gibt es Einschränkungen. Alle Abfragen gegen die sekundäre Datenbank werden automatisch auf das Snapshot Isolation Level abgebildet. Es handelt sich dabei um eine Versionierung der Rows. Microsoft versuchte hiermit die Oracle MVRC (Multi Version Read Consistency) nachzustellen. Tatsächlich muss man die SQL Server Snapshot Isolation eher mit Oracle Flashback vergleichen. Bei der Implementierung des Snapshot Isolation Levels handelt sich um ein nachträglich aufgesetztes Feature und nicht um einen inhärenten Teil des Datenbank-Kernels, wie im Falle Oracle. (Ich werde hierzu in Kürze einen weiteren Blogbeitrag verfassen, wenn ich mich mit der neuen SQL Server 2012 Core Lizenzierung beschäftige.) Für die Praxis entstehen aus der Abbildung auf das Snapshot Isolation Level ernsthafte Restriktionen, derer man sich für den Betrieb in der Praxis bereits vorab bewusst sein sollte: Sollte auf der primären Datenbank eine aktive Transaktion zu dem Zeitpunkt existieren, wenn ein lesbares sekundäres Replikat in die Verfügbarkeitsgruppe aufgenommen wird, werden die Row-Versionen auf der korrespondierenden sekundären Datenbank nicht sofort vollständig verfügbar sein. Eine aktive Transaktion auf dem primären Replikat muss zuerst abgeschlossen (Commit oder Rollback) und dieser Transaktions-Record auf dem sekundären Replikat verarbeitet werden. Bis dahin ist das Isolation Level Mapping auf der sekundären Datenbank unvollständig und Abfragen sind temporär geblockt. Microsoft sagt dazu: "This is needed to guarantee that row versions are available on the secondary replica before executing the query under snapshot isolation as all isolation levels are implicitly mapped to snapshot isolation." (SQL Storage Engine Blog: AlwaysOn: I just enabled Readable Secondary but my query is blocked?)  Grundlegend bedeutet dies, dass ein aktives lesbares Replikat nicht in die Verfügbarkeitsgruppe aufgenommen werden kann, ohne das primäre Replikat vorübergehend stillzulegen. Da Leseoperationen auf das Snapshot Isolation Transaction Level abgebildet werden, kann die Bereinigung von Ghost Records auf dem primären Replikat durch Transaktionen auf einem oder mehreren sekundären Replikaten geblockt werden - z.B. durch eine lang laufende Abfrage auf dem sekundären Replikat. Diese Bereinigung wird auch blockiert, wenn die Verbindung zum sekundären Replikat abbricht oder der Datenaustausch unterbrochen wird. Auch die Log Truncation wird in diesem Zustant verhindert. Wenn dieser Zustand längere Zeit anhält, empfiehlt Microsoft das sekundäre Replikat aus der Verfügbarkeitsgruppe herauszunehmen - was ein ernsthaftes Downtime-Problem darstellt. Die Read-Only Workload auf den sekundären Replikaten kann eingehende DDL Änderungen blockieren. Obwohl die Leseoperationen aufgrund der Row-Versionierung keine Shared Locks halten, führen diese Operatioen zu Sch-S Locks (Schemastabilitätssperren). DDL-Änderungen durch Redo-Operationen können dadurch blockiert werden. Falls DDL aufgrund konkurrierender Lese-Workload blockiert wird und der Schwellenwert für 'Recovery Interval' (eine SQL Server Konfigurationsoption) überschritten wird, generiert der SQL Server das Ereignis sqlserver.lock_redo_blocked, welches Microsoft zum Kill der blockierenden Leser empfiehlt. Auf die Verfügbarkeit der Anwendung wird hierbei keinerlei Rücksicht genommen.   Keine dieser Einschränkungen existiert mit Oracle Active Data Guard.   Backups auf sekundären Replikaten  Über die sekundären Replikate können Backups (BACKUP DATABASE via Transact-SQL) nur als copy-only Backups einer vollständigen Datenbank, Dateien und Dateigruppen erstellt werden. Das Erstellen inkrementeller Backups ist nicht unterstützt, was ein ernsthafter Rückstand ist gegenüber der Backup-Unterstützung physikalischer Standbys unter Oracle Data Guard. Hinweis: Ein möglicher Workaround via Snapshots, bleibt ein Workaround. Eine weitere Einschränkung dieses Features gegenüber Oracle Data Guard besteht darin, dass das Backup eines sekundären Replikats nicht ausgeführt werden kann, wenn es nicht mit dem primären Replikat kommunizieren kann. Darüber hinaus muss das sekundäre Replikat synchronisiert sein oder sich in der Synchronisation befinden, um das Beackup auf dem sekundären Replikat erstellen zu können.   Vergleich von Microsoft AlwaysOn mit der Oracle MAA Ich komme wieder zurück auf die Eingangs erwähnte, mehrfach an mich gestellte Frage "Wann denn - und ob überhaupt - Oracle etwas Vergleichbares wie AlwaysOn bieten würde?" und meine damit verbundene (kurze) Irritation. Wenn Sie diesen Blogbeitrag bis hierher gelesen haben, dann kennen Sie jetzt meine darauf gegebene Antwort. Der eine oder andere Punkt traf dabei nicht immer auf Jeden zu, was auch nicht der tiefere Sinn und Zweck meiner Antwort war. Wenn beispielsweise kein Multi-Subnet mit im Spiel ist, sind alle diesbezüglichen Kritikpunkte zunächst obsolet. Was aber nicht bedeutet, dass sie nicht bereits morgen schon wieder zum Thema werden könnten (Sag niemals "Nie"). In manch anderes Fettnäpfchen tritt man wiederum nicht unbedingt in einer Testumgebung, sondern erst im laufenden Betrieb. Erst recht nicht dann, wenn man sich potenzieller Probleme nicht bewusst ist und keine dedizierten Tests startet. Und wer AlwaysOn erfolgreich positionieren möchte, wird auch gar kein Interesse daran haben, auf mögliche Schwachstellen und den besagten Teufel im Detail aufmerksam zu machen. Das ist keine Unterstellung - es ist nur menschlich. Außerdem ist es verständlich, dass man sich in erster Linie darauf konzentriert "was geht" und "was gut läuft", anstelle auf das "was zu Problemen führen kann" oder "nicht funktioniert". Wer will schon der Miesepeter sein? Für mich selbst gesprochen, kann ich nur sagen, dass ich lieber vorab von allen möglichen Einschränkungen wissen möchte, anstelle sie dann nach einer kurzen Zeit der heilen Welt schmerzhaft am eigenen Leib erfahren zu müssen. Ich bin davon überzeugt, dass es Ihnen nicht anders geht. Nachfolgend deshalb eine Zusammenfassung all jener Punkte, die ich im Vergleich zur Oracle MAA (Maximum Availability Architecture) als unbedingt Erwähnenswert betrachte, falls man eine Evaluierung von Microsoft AlwaysOn in Betracht zieht. 1. AlwaysOn ist eine komplexe Technologie Der SQL Server AlwaysOn Stack ist zusammengesetzt aus drei verschiedenen Technlogien: Windows Server Failover Clustering (WSFC) SQL Server Failover Cluster Instances (FCI) SQL Server Availability Groups (Verfügbarkeitsgruppen) Man kann eine derartige Lösung nicht als nahtlos bezeichnen, wofür auch die vielen von Microsoft dargestellten Einschränkungen sprechen. Während sich frühere SQL Server Versionen in Richtung eigener HA/DR Technologien entwickelten (wie Database Mirroring), empfiehlt Microsoft nun die Migration. Doch weshalb dieser Schwenk? Er führt nicht zu einem konsisten und robusten Angebot an HA/DR Technologie für geschäftskritische Umgebungen.  Liegt die Antwort in meiner These begründet, nach der "Windows was the God ..." noch immer gilt und man die Nachteile der allzu engen Kopplung mit Windows nicht sehen möchte? Entscheiden Sie selbst ... 2. Failover Cluster Instanzen - Kein RAC-Pendant Die SQL Server und Windows Server Clustering Technologie basiert noch immer auf dem veralteten Aktiv-Passiv Modell und führt zu einer Verschwendung von Systemressourcen. In einer Betrachtung von lediglich zwei Knoten erschließt sich auf Anhieb noch nicht der volle Mehrwert eines Aktiv-Aktiv Clusters (wie den Real Application Clusters), wie er von Oracle bereits vor zehn Jahren entwickelt wurde. Doch kennt man die Vorzüge der Skalierbarkeit durch einfaches Hinzufügen weiterer Cluster-Knoten, die dann alle gemeinsam als ein einziges logisches System zusammenarbeiten, versteht man was hinter dem Motto "Pay-as-you-Grow" steckt. In einem Aktiv-Aktiv Cluster geht es zwar auch um Hochverfügbarkeit - und ein Failover erfolgt zudem schneller, als in einem Aktiv-Passiv Modell - aber es geht eben nicht nur darum. An dieser Stelle sei darauf hingewiesen, dass die Oracle 11g Standard Edition bereits die Nutzung von Oracle RAC bis zu vier Sockets kostenfrei beinhaltet. Möchten Sie dazu Windows nutzen, benötigen Sie keine Windows Server Enterprise Edition, da Oracle 11g die eigene Clusterware liefert. Sie kommen in den Genuss von Hochverfügbarkeit und Skalierbarkeit und können dazu die günstigere Windows Server Standard Edition nutzen. 3. SQL Server Multi-Subnet Clustering - Abhängigkeit zu 3rd Party Storage Mirroring  Die SQL Server Multi-Subnet Clustering Architektur unterstützt den Aufbau eines Stretch Clusters, basiert dabei aber auf dem Aktiv-Passiv Modell. Das eigentlich Problematische ist jedoch, dass man sich zur Absicherung der Datenbank auf 3rd Party Storage Mirroring Technologie verlässt, ohne Integration zwischen dem Windows Server Failover Clustering (WSFC) und der darunterliegenden Mirroring Technologie. Wenn nun im Cluster ein Failover auf Instanzen-Ebene erfolgt, existiert keine Koordination mit einem möglichen Failover auf Ebene des Storage-Array. 4. Availability Groups (Verfügbarkeitsgruppen) - Vier, oder doch nur Zwei? Ein primäres Replikat erlaubt bis zu vier sekundäre Replikate innerhalb einer Verfügbarkeitsgruppe, jedoch nur zwei im Synchronen Commit Modus. Während dies zwar einen Vorteil gegenüber dem stringenten 1:1 Modell unter Database Mirroring darstellt, fällt der SQL Server 2012 damit immer noch weiter zurück hinter Oracle Data Guard mit bis zu 30 direkten Stanbdy Zielen - und vielen weiteren durch kaskadierende Ziele möglichen. Damit eignet sich Oracle Active Data Guard auch für die Bereitstellung einer Reader-Farm Skalierbarkeit für Internet-basierende Unternehmen. Mit AwaysOn Verfügbarkeitsgruppen ist dies nicht möglich. 5. Availability Groups (Verfügbarkeitsgruppen) - kein asynchrones Switchover  Die Technologie der Verfügbarkeitsgruppen wird auch als geeignetes Mittel für administrative Aufgaben positioniert - wie Upgrades oder Wartungsarbeiten. Man muss sich jedoch einem gravierendem Defizit bewusst sein: Im asynchronen Verfügbarkeitsmodus besteht die einzige Möglichkeit für Role Transition im Forced Failover mit Datenverlust! Um den Verlust von Daten durch geplante Wartungsarbeiten zu vermeiden, muss man den synchronen Verfügbarkeitsmodus konfigurieren, was jedoch ernstzunehmende Auswirkungen auf WAN Deployments nach sich zieht. Spinnt man diesen Gedanken zu Ende, kommt man zu dem Schluss, dass die Technologie der Verfügbarkeitsgruppen für geplante Wartungsarbeiten in einem derartigen Umfeld nicht effektiv genutzt werden kann. 6. Automatisches Failover - Nicht immer möglich Sowohl die SQL Server FCI, als auch Verfügbarkeitsgruppen unterstützen automatisches Failover. Möchte man diese jedoch kombinieren, wird das Ergebnis kein automatisches Failover sein. Denn ihr Zusammentreffen im Failover-Fall führt zu Race Conditions (Wettlaufsituationen), weshalb diese Konfiguration nicht länger das automatische Failover zu einem Replikat in einer Verfügbarkeitsgruppe erlaubt. Auch hier bestätigt sich wieder die tiefere Problematik von AlwaysOn, mit einer Zusammensetzung aus unterschiedlichen Technologien und der Abhängigkeit zu Windows. 7. Problematische RTO (Recovery Time Objective) Microsoft postioniert die SQL Server Multi-Subnet Clustering Architektur als brauchbare HA/DR Architektur. Bedenkt man jedoch die Problematik im Zusammenhang mit DNS Replikation und den möglichen langen Wartezeiten auf Client-Seite von bis zu 16 Minuten, sind strenge RTO Anforderungen (Recovery Time Objectives) nicht erfüllbar. Im Gegensatz zu Oracle besitzt der SQL Server keine Datenbank-integrierten Technologien, wie Oracle Fast Application Notification (FAN) oder Oracle Fast Connection Failover (FCF). 8. Problematische RPO (Recovery Point Objective) SQL Server ermöglicht Forced Failover (erzwungenes Failover), bietet jedoch keine Möglichkeit zur automatischen Übertragung der letzten Datenbits von einem alten zu einem neuen primären Replikat, wenn der Verfügbarkeitsmodus asynchron war. Oracle Data Guard hingegen bietet diese Unterstützung durch das Flush Redo Feature. Dies sichert "Zero Data Loss" und beste RPO auch in erzwungenen Failover-Situationen. 9. Lesbare Sekundäre Replikate mit Einschränkungen Aufgrund des Snapshot Isolation Transaction Level für lesbare sekundäre Replikate, besitzen diese Einschränkungen mit Auswirkung auf die primäre Datenbank. Die Bereinigung von Ghost Records auf der primären Datenbank, wird beeinflusst von lang laufenden Abfragen auf der lesabaren sekundären Datenbank. Die lesbare sekundäre Datenbank kann nicht in die Verfügbarkeitsgruppe aufgenommen werden, wenn es aktive Transaktionen auf der primären Datenbank gibt. Zusätzlich können DLL Änderungen auf der primären Datenbank durch Abfragen auf der sekundären blockiert werden. Und imkrementelle Backups werden hier nicht unterstützt.   Keine dieser Restriktionen existiert unter Oracle Data Guard.

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  • marshal data too short!!!

    - by Nitin Garg
    My application requires to keep large data objects in session. There are like 3-4 data objects each created by parsing a csv containing 150 X 20 cells having strings of 3-4 characters. My application shows this error- "marshal data too short". I tried this- Deleting the old session table. Deleting the old migration for session table. Creating a new migration using rake db: sessions:create. editing the migration manually, changing "text: data" to "longtext: data". running the migration using rake db: migrate. now when i open my application, i see this page- link text please someone help me, this is getting on my nerves!! other details of application-- In view "index.html.erb"- There is a link that makes ajax call to an action in controller, that action parses large csv file and makes an object out of it. this object is stored in session. ERROR LOG ` ArgumentError in Scoring#index Showing app/views/scoring/index.html.erb where line #4 raised: marshal data too short Extracted source (around line #4): 1: 2: 3: 4: <%= link_to_remote "get csv file", 5: :url = { :action = 'show_static_1' }, 6: :update = "static_score", 7: :complete = "$('static_score').update(request.responseText)" % Application Trace | Framework Trace | Full Trace /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:71:in load' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:71:in unmarshal' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:110:in data' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:292:in get_session' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1448:in silence' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:288:in get_session' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:168:in load_session' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:62:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:62:in load!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:70:in stale_session_check!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:61:in load!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:28:in []' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/request_forgery_protection.rb:106:in form_authenticity_token' (eval):2:in send' (eval):2:in form_authenticity_token' app/views/scoring/index.html.erb:4:in _run_erb_app47views47scoring47index46html46erb' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:71:in load' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:71:in unmarshal' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:110:in data' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:292:in get_session' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1448:in silence' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:288:in get_session' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:168:in load_session' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:62:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:62:in load!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:70:in stale_session_check!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:61:in load!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:28:in []' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/request_forgery_protection.rb:106:in form_authenticity_token' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/helpers/prototype_helper.rb:1065:in options_for_ajax' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/helpers/prototype_helper.rb:449:in remote_function' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/helpers/prototype_helper.rb:256:in link_to_remote' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/renderable.rb:34:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/renderable.rb:34:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:306:in with_template' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/renderable.rb:30:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/template.rb:205:in render_template' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:265:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:348:in _render_with_layout' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:262:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1250:in render_for_file' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:945:in render_without_benchmark' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:51:in render' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:10:in realtime' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:51:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1326:in default_render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1338:in perform_action_without_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:617:in call_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:610:in perform_action_without_benchmark' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:10:in realtime' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:160:in perform_action_without_flash' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/flash.rb:146:in perform_action' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in process_without_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:606:in process' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:391:in process' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:386:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/routing/route_set.rb:437:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:87:in dispatch' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:121:in _call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:130:in build_middleware_stack' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/string_coercion.rb:25:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/string_coercion.rb:25:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/head.rb:9:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/params_parser.rb:15:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:122:in call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:29:in call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in cache' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:9:in cache' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:28:in call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/failsafe.rb:26:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in synchronize' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:114:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/reloader.rb:34:in run' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:108:in call' /usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/rack/static.rb:31:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in each' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in call' /usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/rack/log_tailer.rb:17:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/content_length.rb:13:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/chunked.rb:15:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/mongrel.rb:64:in process' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in process_client' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in each' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in process_client' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in run' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in initialize' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in new' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in run' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in initialize' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in new' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in run' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/mongrel.rb:34:in run' /usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/commands/server.rb:111 /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in gem_original_require' /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in require' script/server:3 /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:71:in load' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:71:in unmarshal' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:110:in data' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:292:in get_session' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1448:in silence' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/session_store.rb:288:in get_session' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:168:in load_session' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:62:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:62:in load!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:70:in stale_session_check!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:61:in load!' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:28:in []' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/request_forgery_protection.rb:106:in form_authenticity_token' (eval):2:in send' (eval):2:in form_authenticity_token' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/helpers/prototype_helper.rb:1065:in options_for_ajax' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/helpers/prototype_helper.rb:449:in remote_function' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/helpers/prototype_helper.rb:256:in link_to_remote' /app/views/scoring/index.html.erb:4:in _run_erb_app47views47scoring47index46html46erb' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/renderable.rb:34:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/renderable.rb:34:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:306:in with_template' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/renderable.rb:30:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/template.rb:205:in render_template' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:265:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:348:in _render_with_layout' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_view/base.rb:262:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1250:in render_for_file' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:945:in render_without_benchmark' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:51:in render' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:10:in realtime' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:51:in render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1326:in default_render' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1338:in perform_action_without_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:617:in call_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:610:in perform_action_without_benchmark' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:10:in realtime' /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in ms' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in perform_action_without_rescue' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:160:in perform_action_without_flash' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/flash.rb:146:in perform_action' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in send' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in process_without_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:606:in process' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:391:in process' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:386:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/routing/route_set.rb:437:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:87:in dispatch' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:121:in _call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:130:in build_middleware_stack' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/string_coercion.rb:25:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/string_coercion.rb:25:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/head.rb:9:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/methodoverride.rb:24:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/params_parser.rb:15:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:122:in call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:29:in call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in cache' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:9:in cache' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:28:in call' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/failsafe.rb:26:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in synchronize' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/lock.rb:11:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:114:in call' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/reloader.rb:34:in run' /usr/lib/ruby/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:108:in call' /usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/rack/static.rb:31:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:46:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in each' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/urlmap.rb:40:in call' /usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/rack/log_tailer.rb:17:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/content_length.rb:13:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/chunked.rb:15:in call' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/mongrel.rb:64:in process' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in process_client' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in each' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in process_client' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in run' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in initialize' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in new' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in run' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in initialize' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in new' /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in run' /usr/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/handler/mongrel.rb:34:in run' /usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/commands/server.rb:111 /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in gem_original_require' /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' script/server:3 Request Parameters: None Show session dump Response Headers: {"Content-Type"="text/html", "Cache-Control"="no-cache"} `

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  • Simple Self Join Query Bad Performance

    - by user1514042
    Could anyone advice on how do I improve the performance of the following query. Note, the problem seems to be caused by where clause. Data (table contains a huge set of rows - 500K+, the set of parameters it's called with assums the return of 2-5K records per query, which takes 8-10 minutes currently): USE [SomeDb] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Data]( [x] [money] NOT NULL, [y] [money] NOT NULL, CONSTRAINT [PK_Data] PRIMARY KEY CLUSTERED ( [x] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO The Query select top 10000 s.x as sx, e.x as ex, s.y as sy, e.y as ey, e.y - s.y as y_delta, e.x - s.x as x_delta from Data s inner join Data e on e.x > s.x and e.x - s.x between xFrom and xTo --where e.y - s.y > @yDelta -- when uncommented causes a huge delay Update 1 - Execution Plan <?xml version="1.0" encoding="utf-16"?> <ShowPlanXML xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" Version="1.2" Build="11.0.2100.60" xmlns="http://schemas.microsoft.com/sqlserver/2004/07/showplan"> <BatchSequence> <Batch> <Statements> <StmtSimple StatementCompId="1" StatementEstRows="100" StatementId="1" StatementOptmLevel="FULL" StatementOptmEarlyAbortReason="GoodEnoughPlanFound" StatementSubTreeCost="0.0263655" StatementText="select top 100&#xD;&#xA;s.x as sx,&#xD;&#xA;e.x as ex,&#xD;&#xA;s.y as sy,&#xD;&#xA;e.y as ey,&#xD;&#xA;e.y - s.y as y_delta,&#xD;&#xA;e.x - s.x as x_delta&#xD;&#xA;from Data s &#xD;&#xA; inner join Data e&#xD;&#xA; on e.x &gt; s.x and e.x - s.x between 100 and 105&#xD;&#xA;where e.y - s.y &gt; 0.01&#xD;&#xA;" StatementType="SELECT" QueryHash="0xAAAC02AC2D78CB56" QueryPlanHash="0x747994153CB2D637" RetrievedFromCache="true"> <StatementSetOptions ANSI_NULLS="true" ANSI_PADDING="true" ANSI_WARNINGS="true" ARITHABORT="true" CONCAT_NULL_YIELDS_NULL="true" NUMERIC_ROUNDABORT="false" QUOTED_IDENTIFIER="true" /> <QueryPlan DegreeOfParallelism="0" NonParallelPlanReason="NoParallelPlansInDesktopOrExpressEdition" CachedPlanSize="24" CompileTime="13" CompileCPU="13" CompileMemory="424"> <MemoryGrantInfo SerialRequiredMemory="0" SerialDesiredMemory="0" /> <OptimizerHardwareDependentProperties EstimatedAvailableMemoryGrant="52199" EstimatedPagesCached="14561" EstimatedAvailableDegreeOfParallelism="4" /> <RelOp AvgRowSize="55" EstimateCPU="1E-05" EstimateIO="0" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row" EstimateRows="100" LogicalOp="Compute Scalar" NodeId="0" Parallel="false" PhysicalOp="Compute Scalar" EstimatedTotalSubtreeCost="0.0263655"> <OutputList> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> <ColumnReference Column="Expr1004" /> <ColumnReference Column="Expr1005" /> </OutputList> <ComputeScalar> <DefinedValues> <DefinedValue> <ColumnReference Column="Expr1004" /> <ScalarOperator ScalarString="[SomeDb].[dbo].[Data].[y] as [e].[y]-[SomeDb].[dbo].[Data].[y] as [s].[y]"> <Arithmetic Operation="SUB"> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </Identifier> </ScalarOperator> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> </Identifier> </ScalarOperator> </Arithmetic> </ScalarOperator> </DefinedValue> <DefinedValue> <ColumnReference Column="Expr1005" /> <ScalarOperator ScalarString="[SomeDb].[dbo].[Data].[x] as [e].[x]-[SomeDb].[dbo].[Data].[x] as [s].[x]"> <Arithmetic Operation="SUB"> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> </Identifier> </ScalarOperator> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> </Identifier> </ScalarOperator> </Arithmetic> </ScalarOperator> </DefinedValue> </DefinedValues> <RelOp AvgRowSize="39" EstimateCPU="1E-05" EstimateIO="0" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row" EstimateRows="100" LogicalOp="Top" NodeId="1" Parallel="false" PhysicalOp="Top" EstimatedTotalSubtreeCost="0.0263555"> <OutputList> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </OutputList> <RunTimeInformation> <RunTimeCountersPerThread Thread="0" ActualRows="100" ActualEndOfScans="1" ActualExecutions="1" /> </RunTimeInformation> <Top RowCount="false" IsPercent="false" WithTies="false"> <TopExpression> <ScalarOperator ScalarString="(100)"> <Const ConstValue="(100)" /> </ScalarOperator> </TopExpression> <RelOp AvgRowSize="39" EstimateCPU="151828" EstimateIO="0" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row" EstimateRows="100" LogicalOp="Inner Join" NodeId="2" Parallel="false" PhysicalOp="Nested Loops" EstimatedTotalSubtreeCost="0.0263455"> <OutputList> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </OutputList> <RunTimeInformation> <RunTimeCountersPerThread Thread="0" ActualRows="100" ActualEndOfScans="0" ActualExecutions="1" /> </RunTimeInformation> <NestedLoops Optimized="false"> <OuterReferences> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </OuterReferences> <RelOp AvgRowSize="23" EstimateCPU="1.80448" EstimateIO="3.76461" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row" EstimateRows="1" LogicalOp="Clustered Index Scan" NodeId="3" Parallel="false" PhysicalOp="Clustered Index Scan" EstimatedTotalSubtreeCost="0.0032831" TableCardinality="1640290"> <OutputList> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </OutputList> <RunTimeInformation> <RunTimeCountersPerThread Thread="0" ActualRows="15225" ActualEndOfScans="0" ActualExecutions="1" /> </RunTimeInformation> <IndexScan Ordered="false" ForcedIndex="false" ForceScan="false" NoExpandHint="false"> <DefinedValues> <DefinedValue> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </DefinedValue> </DefinedValues> <Object Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Index="[PK_Data]" Alias="[e]" IndexKind="Clustered" /> </IndexScan> </RelOp> <RelOp AvgRowSize="23" EstimateCPU="0.902317" EstimateIO="1.88387" EstimateRebinds="1" EstimateRewinds="0" EstimatedExecutionMode="Row" EstimateRows="100" LogicalOp="Clustered Index Seek" NodeId="4" Parallel="false" PhysicalOp="Clustered Index Seek" EstimatedTotalSubtreeCost="0.0263655" TableCardinality="1640290"> <OutputList> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> </OutputList> <RunTimeInformation> <RunTimeCountersPerThread Thread="0" ActualRows="100" ActualEndOfScans="15224" ActualExecutions="15225" /> </RunTimeInformation> <IndexScan Ordered="true" ScanDirection="FORWARD" ForcedIndex="false" ForceSeek="false" ForceScan="false" NoExpandHint="false" Storage="RowStore"> <DefinedValues> <DefinedValue> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> </DefinedValue> </DefinedValues> <Object Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Index="[PK_Data]" Alias="[s]" IndexKind="Clustered" /> <SeekPredicates> <SeekPredicateNew> <SeekKeys> <EndRange ScanType="LT"> <RangeColumns> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> </RangeColumns> <RangeExpressions> <ScalarOperator ScalarString="[SomeDb].[dbo].[Data].[x] as [e].[x]"> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> </Identifier> </ScalarOperator> </RangeExpressions> </EndRange> </SeekKeys> </SeekPredicateNew> </SeekPredicates> <Predicate> <ScalarOperator ScalarString="([SomeDb].[dbo].[Data].[x] as [e].[x]-[SomeDb].[dbo].[Data].[x] as [s].[x])&gt;=($100.0000) AND ([SomeDb].[dbo].[Data].[x] as [e].[x]-[SomeDb].[dbo].[Data].[x] as [s].[x])&lt;=($105.0000) AND ([SomeDb].[dbo].[Data].[y] as [e].[y]-[SomeDb].[dbo].[Data].[y] as [s].[y])&gt;(0.01)"> <Logical Operation="AND"> <ScalarOperator> <Compare CompareOp="GE"> <ScalarOperator> <Arithmetic Operation="SUB"> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> </Identifier> </ScalarOperator> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> </Identifier> </ScalarOperator> </Arithmetic> </ScalarOperator> <ScalarOperator> <Const ConstValue="($100.0000)" /> </ScalarOperator> </Compare> </ScalarOperator> <ScalarOperator> <Compare CompareOp="LE"> <ScalarOperator> <Arithmetic Operation="SUB"> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="x" /> </Identifier> </ScalarOperator> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="x" /> </Identifier> </ScalarOperator> </Arithmetic> </ScalarOperator> <ScalarOperator> <Const ConstValue="($105.0000)" /> </ScalarOperator> </Compare> </ScalarOperator> <ScalarOperator> <Compare CompareOp="GT"> <ScalarOperator> <Arithmetic Operation="SUB"> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[e]" Column="y" /> </Identifier> </ScalarOperator> <ScalarOperator> <Identifier> <ColumnReference Database="[SomeDb]" Schema="[dbo]" Table="[Data]" Alias="[s]" Column="y" /> </Identifier> </ScalarOperator> </Arithmetic> </ScalarOperator> <ScalarOperator> <Const ConstValue="(0.01)" /> </ScalarOperator> </Compare> </ScalarOperator> </Logical> </ScalarOperator> </Predicate> </IndexScan> </RelOp> </NestedLoops> </RelOp> </Top> </RelOp> </ComputeScalar> </RelOp> </QueryPlan> </StmtSimple> </Statements> </Batch> </BatchSequence> </ShowPlanXML>

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