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  • compass-rails 1.03 - TypeError: can't convert nil into String

    - by Romiko
    I am running: ruby 1.9.3p392 (2013-02-22) [i386-mingw32] compass-rails 1.0.3 I used the Windows RailsInstaller to install Ruby on Rails Gemfile group :assets do gem 'sass-rails', '~> 3.2.3' gem 'coffee-rails', '~> 3.2.1' gem 'compass-rails','~> 1.0.2' # See https://github.com/sstephenson/execjs#readme for more supported runtimes # gem 'therubyracer', :platforms => :ruby gem 'uglifier', '>= 1.0.3' end I am currently experiencing issues importing sprites. My sprites are in: assets/images/source in my _shared.scss file I have: //Sprites @import "./source/*.png"; $source-sprite-dimensions: true; In my application.scss I have: /* * This is a manifest file that'll be compiled into application.css, which will include all the files * listed below. * * Any CSS and SCSS file within this directory, lib/assets/stylesheets, vendor/assets/stylesheets, * or vendor/assets/stylesheets of plugins, if any, can be referenced here using a relative path. * * You're free to add application-wide styles to this file and they'll appear at the top of the * compiled file, but it's generally better to create a new file per style scope. * *= require_self */ @import "_shared.scss"; @import "baseline.scss"; @import "global.scss"; @import "normalize.scss"; @import "print.scss"; @import "desktop.scss"; @import "tablet.scss"; @import "home.css.scss"; I am also using rails server and not compass watcher. However when I browse to the page at localhost:3000/assets/application.css, I get the following error: body:before { font-weight: bold; content: "\000a TypeError: can't convert nil into String\000a (in c:\002f RangerRomOnRails\002f RangerRom\002f app\002f assets\002f stylesheets\002f desktop.scss)"; } body:after { content: "\000a C:\002f RailsInstaller\002f Ruby1.9.3\002f lib\002f ruby\002f gems\002f 1.9.1\002f gems\002f compass-0.12.2\002f lib\002f compass\002f sass_extensions\002f functions\002f image_size.rb:17:in `extname'"; } Here is the full stack trace: compass (0 .12.2) lib/compass/sass_extensions/functions/image_size.rb:17:in `extname' compass (0.12.2) lib/compass/sass_extensions/functions/image_size.rb:17:in `initialize' compass (0.12.2) lib/compass/sass_extensions/functions/image_size.rb:50:in `new' compass (0.12.2) lib/compass/sass_extensions/functions/image_size.rb:50:in `image_dimensions' compass (0.12.2) lib/compass/sass_extensions/functions/image_size.rb:4:in `image_width' sass (3.2.9) lib/sass/script/funcall.rb:112:in `_perform' sass (3.2.9) lib/sass/script/node.rb:40:in `perform' sass (3.2.9) lib/sass/tree/visitors/perform.rb:298:in `visit_prop' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:100:in `visit' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `map' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:109:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:121:in `with_environment' sass (3.2.9) lib/sass/tree/visitors/perform.rb:108:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `block in visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:320:in `visit_rule' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:100:in `visit' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `map' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:109:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:121:in `with_environment' sass (3.2.9) lib/sass/tree/visitors/perform.rb:108:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `block in visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:320:in `visit_rule' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:100:in `visit' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `map' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:109:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:121:in `with_environment' sass (3.2.9) lib/sass/tree/visitors/perform.rb:108:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `block in visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:362:in `visit_media' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:100:in `visit' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `map' sass (3.2.9) lib/sass/tree/visitors/base.rb:53:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:109:in `block in visit_children' sass (3.2.9) lib/sass/tree/visitors/perform.rb:121:in `with_environment' sass (3.2.9) lib/sass/tree/visitors/perform.rb:108:in `visit_children' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `block in visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:128:in `visit_root' sass (3.2.9) lib/sass/tree/visitors/base.rb:37:in `visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:100:in `visit' sass (3.2.9) lib/sass/tree/visitors/perform.rb:7:in `visit' sass (3.2.9) lib/sass/tree/root_node.rb:20:in `render' sass (3.2.9) lib/sass/engine.rb:315:in `_render' sass (3.2.9) lib/sass/engine.rb:262:in `render' sass-rails (3.2.6) lib/sass/rails/template_handlers.rb:106:in `evaluate' tilt (1.4.1) lib/tilt/template.rb:103:in `render' sprockets (2.2.2) lib/sprockets/context.rb:193:in `block in evaluate' sprockets (2.2.2) lib/sprockets/context.rb:190:in `each' sprockets (2.2.2) lib/sprockets/context.rb:190:in `evaluate' sprockets (2.2.2) lib/sprockets/processed_asset.rb:12:in `initialize' sprockets (2.2.2) lib/sprockets/base.rb:249:in `new' sprockets (2.2.2) lib/sprockets/base.rb:249:in `block in build_asset' sprockets (2.2.2) lib/sprockets/base.rb:270:in `circular_call_protection' sprockets (2.2.2) lib/sprockets/base.rb:248:in `build_asset' sprockets (2.2.2) lib/sprockets/index.rb:93:in `block in build_asset' sprockets (2.2.2) lib/sprockets/caching.rb:19:in `cache_asset' sprockets (2.2.2) lib/sprockets/index.rb:92:in `build_asset' sprockets (2.2.2) lib/sprockets/base.rb:169:in `find_asset' sprockets (2.2.2) lib/sprockets/index.rb:60:in `find_asset' sprockets (2.2.2) lib/sprockets/processed_asset.rb:111:in `block in resolve_dependencies' sprockets (2.2.2) lib/sprockets/processed_asset.rb:105:in `each' sprockets (2.2.2) lib/sprockets/processed_asset.rb:105:in `resolve_dependencies' sprockets (2.2.2) lib/sprockets/processed_asset.rb:97:in `build_required_assets' sprockets (2.2.2) lib/sprockets/processed_asset.rb:16:in `initialize' sprockets (2.2.2) lib/sprockets/base.rb:249:in `new' sprockets (2.2.2) lib/sprockets/base.rb:249:in `block in build_asset' sprockets (2.2.2) lib/sprockets/base.rb:270:in `circular_call_protection' sprockets (2.2.2) lib/sprockets/base.rb:248:in `build_asset' sprockets (2.2.2) lib/sprockets/index.rb:93:in `block in build_asset' sprockets (2.2.2) lib/sprockets/caching.rb:19:in `cache_asset' sprockets (2.2.2) lib/sprockets/index.rb:92:in `build_asset' sprockets (2.2.2) lib/sprockets/base.rb:169:in `find_asset' sprockets (2.2.2) lib/sprockets/index.rb:60:in `find_asset' sprockets (2.2.2) lib/sprockets/bundled_asset.rb:38:in `init_with' sprockets (2.2.2) lib/sprockets/asset.rb:24:in `from_hash' sprockets (2.2.2) lib/sprockets/caching.rb:15:in `cache_asset' sprockets (2.2.2) lib/sprockets/index.rb:92:in `build_asset' sprockets (2.2.2) lib/sprockets/base.rb:169:in `find_asset' sprockets (2.2.2) lib/sprockets/index.rb:60:in `find_asset' sprockets (2.2.2) lib/sprockets/environment.rb:78:in `find_asset' sprockets (2.2.2) lib/sprockets/base.rb:177:in `[]' actionpack (3.2.13) lib/sprockets/helpers/rails_helper.rb:126:in `asset_for' actionpack (3.2.13) lib/sprockets/helpers/rails_helper.rb:44:in `block in stylesheet_link_tag' actionpack (3.2.13) lib/sprockets/helpers/rails_helper.rb:43:in `collect' actionpack (3.2.13) lib/sprockets/helpers/rails_helper.rb:43:in `stylesheet_link_tag' app/views/layouts/application.html.erb:16:in `_app_views_layouts_application_html_erb___824639613_33845076' actionpack (3.2.13) lib/action_view/template.rb:145:in `block in render' activesupport (3.2.13) lib/active_support/notifications.rb:125:in `instrument' actionpack (3.2.13) lib/action_view/template.rb:143:in `render' actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:59:in `render_with_layout' actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:45:in `render_template' actionpack (3.2.13) lib/action_view/renderer/template_renderer.rb:18:in `render' actionpack (3.2.13) lib/action_view/renderer/renderer.rb:36:in `render_template' actionpack (3.2.13) lib/action_view/renderer/renderer.rb:17:in `render' actionpack (3.2.13) lib/abstract_controller/rendering.rb:110:in `_render_template' actionpack (3.2.13) lib/action_controller/metal/streaming.rb:225:in `_render_template' actionpack (3.2.13) lib/abstract_controller/rendering.rb:103:in `render_to_body' actionpack (3.2.13) lib/action_controller/metal/renderers.rb:28:in `render_to_body' actionpack (3.2.13) lib/action_controller/metal/compatibility.rb:50:in `render_to_body' actionpack (3.2.13) lib/abstract_controller/rendering.rb:88:in `render' actionpack (3.2.13) lib/action_controller/metal/rendering.rb:16:in `render' actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:40:in `block (2 levels) in render' activesupport (3.2.13) lib/active_support/core_ext/benchmark.rb:5:in `block in ms' C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/benchmark.rb:295:in `realtime' activesupport (3.2.13) lib/active_support/core_ext/benchmark.rb:5:in `ms' actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:40:in `block in render' actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:83:in `cleanup_view_runtime' activerecord (3.2.13) lib/active_record/railties/controller_runtime.rb:24:in `cleanup_view_runtime' actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:39:in `render' actionpack (3.2.13) lib/action_controller/metal/implicit_render.rb:10:in `default_render' actionpack (3.2.13) lib/action_controller/metal/implicit_render.rb:5:in `send_action' actionpack (3.2.13) lib/abstract_controller/base.rb:167:in `process_action' actionpack (3.2.13) lib/action_controller/metal/rendering.rb:10:in `process_action' actionpack (3.2.13) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (3.2.13) lib/active_support/callbacks.rb:414:in `_run__956028316__process_action__416811168__callbacks' activesupport (3.2.13) lib/active_support/callbacks.rb:405:in `__run_callback' activesupport (3.2.13) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks' activesupport (3.2.13) lib/active_support/callbacks.rb:81:in `run_callbacks' actionpack (3.2.13) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (3.2.13) lib/action_controller/metal/rescue.rb:29:in `process_action' actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' activesupport (3.2.13) lib/active_support/notifications.rb:123:in `block in instrument' activesupport (3.2.13) lib/active_support/notifications/instrumenter.rb:20:in `instrument' activesupport (3.2.13) lib/active_support/notifications.rb:123:in `instrument' actionpack (3.2.13) lib/action_controller/metal/instrumentation.rb:29:in `process_action' actionpack (3.2.13) lib/action_controller/metal/params_wrapper.rb:207:in `process_action' activerecord (3.2.13) lib/active_record/railties/controller_runtime.rb:18:in `process_action' actionpack (3.2.13) lib/abstract_controller/base.rb:121:in `process' actionpack (3.2.13) lib/abstract_controller/rendering.rb:45:in `process' actionpack (3.2.13) lib/action_controller/metal.rb:203:in `dispatch' actionpack (3.2.13) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' actionpack (3.2.13) lib/action_controller/metal.rb:246:in `block in action' actionpack (3.2.13) lib/action_dispatch/routing/route_set.rb:73:in `call' actionpack (3.2.13) lib/action_dispatch/routing/route_set.rb:73:in `dispatch' actionpack (3.2.13) lib/action_dispatch/routing/route_set.rb:36:in `call' journey (1.0.4) lib/journey/router.rb:68:in `block in call' journey (1.0.4) lib/journey/router.rb:56:in `each' journey (1.0.4) lib/journey/router.rb:56:in `call' actionpack (3.2.13) lib/action_dispatch/routing/route_set.rb:612:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' rack (1.4.5) lib/rack/etag.rb:23:in `call' rack (1.4.5) lib/rack/conditionalget.rb:25:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/head.rb:14:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/params_parser.rb:21:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/flash.rb:242:in `call' rack (1.4.5) lib/rack/session/abstract/id.rb:210:in `context' rack (1.4.5) lib/rack/session/abstract/id.rb:205:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/cookies.rb:341:in `call' activerecord (3.2.13) lib/active_record/query_cache.rb:64:in `call' activerecord (3.2.13) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call' activesupport (3.2.13) lib/active_support/callbacks.rb:405:in `_run__360878605__call__248365880__callbacks' activesupport (3.2.13) lib/active_support/callbacks.rb:405:in `__run_callback' activesupport (3.2.13) lib/active_support/callbacks.rb:385:in `_run_call_callbacks' activesupport (3.2.13) lib/active_support/callbacks.rb:81:in `run_callbacks' actionpack (3.2.13) lib/action_dispatch/middleware/callbacks.rb:27:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/reloader.rb:65:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/remote_ip.rb:31:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call' railties (3.2.13) lib/rails/rack/logger.rb:32:in `call_app' railties (3.2.13) lib/rails/rack/logger.rb:16:in `block in call' activesupport (3.2.13) lib/active_support/tagged_logging.rb:22:in `tagged' railties (3.2.13) lib/rails/rack/logger.rb:16:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/request_id.rb:22:in `call' rack (1.4.5) lib/rack/methodoverride.rb:21:in `call' rack (1.4.5) lib/rack/runtime.rb:17:in `call' activesupport (3.2.13) lib/active_support/cache/strategy/local_cache.rb:72:in `call' rack (1.4.5) lib/rack/lock.rb:15:in `call' actionpack (3.2.13) lib/action_dispatch/middleware/static.rb:63:in `call' railties (3.2.13) lib/rails/engine.rb:479:in `call' railties (3.2.13) lib/rails/application.rb:223:in `call' rack (1.4.5) lib/rack/content_length.rb:14:in `call' railties (3.2.13) lib/rails/rack/log_tailer.rb:17:in `call' rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service' C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service' C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run' C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'

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  • How to display a hierarchical skill tree in php

    - by user3587554
    If I have skill data set up in a tree format (where earlier skills are prerequisites for later ones), how would I display it as a tree, using php? The parent would be on top and have 3 children. Each of these children can then have one more child so its parent would be directly above it. I'm having trouble figuring out how to add the root element in the middle of the top div, and the child of the children below each child of the root. I'm not looking for code, but an explanation of how to do it. My data in array form is this: Data: Array ( [1] => Array ( [id] => 1 [title] => Jutsu [description] => Skill that makes you awesomer at using ninjutsu [tiers] => 1 [prereq] => [image] => images/skills/jutsu.png [children] => Array ( [2] => Array ( [id] => 2 [title] => fireball [description] => Increase your damage with fire jutsu and weapons [tiers] => 5 [prereq] => 1 [image] => images/skills/fireball.png [children] => Array ( [5] => Array ( [id] => 5 [title] => pin point [description] => Increases jutsu accuracy [tiers] => 5 [prereq] => 2 [image] => images/skills/pinpoint.png ) ) ) [3] => Array ( [id] => 3 [title] => synergy [description] => Reduce the amount of chakra needed to use ninjutsu [tiers] => 1 [prereq] => 1 [image] => images/skills/synergy.png ) [4] => Array ( [id] => 4 [title] => ebb & flow [description] => Increase the damage of water jutsu, water weapons, and reduce the damage of jutsu and weapons that use water element [tiers] => 5 [prereq] => 1 [image] => images/skills/ebbandflow.png [children] => Array ( [6] => Array ( [id] => 6 [title] => IQ [description] => Decrease the time it takes to learn a jutsu [tiers] => 5 [prereq] => 4 [image] => images/skills/iq.png ) ) ) ) ) ) An example would be this demo image minus the hover stuff.

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  • Tic-Tac-Toe AI: How to Make the Tree?

    - by cam
    I'm having a huge block trying to understand "trees" while making a Tic-Tac-Toe bot. I understand the concept, but I can't figure out to implement them. Can someone show me an example of how a tree should be generated for such a case? Or a good tutorial on generating trees? I guess the hard part is generating partial trees. I know how to implement generating a whole tree, but not parts of it.

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  • Closure Tables - Is this enough data to display a tree view?

    - by James Pitt
    Here is the table I have created by testing the closure table method. | id | parentId | childId | hops | | | | | 270 | 6 | 6 | 0 | 271 | 7 | 7 | 0 | 272 | 8 | 8 | 0 | 273 | 9 | 9 | 0 | 276 | 10 | 10 | 0 | 281 | 9 | 10 | 1 | 282 | 7 | 9 | 1 | 283 | 7 | 10 | 2 | 285 | 7 | 8 | 1 | 286 | 6 | 7 | 1 | 287 | 6 | 9 | 2 | 288 | 6 | 10 | 3 | 289 | 6 | 8 | 2 | 293 | 6 | 9 | 1 | 294 | 6 | 10 | 2 I am trying to create a simple tree of this using PHP. There does not seem to be enough data to create the table. For example, when I look purely at parentId = 6: -Part 6 -Part 7 - ? - ? -Part 9 - ? - ? We know that parts 8 and 10 exists below Part 7 or 9, but not which. We know that part 10 exists at both 3 and 4 nodes deep but where? If I look at other data in the table it is possible to tell it should be: - Part 6 - Part 7 - Part 9 - Part 10 - Part 9 - Part 10 I thought one of the benefits of closure tables was there was no need for recursive queries? Could you help explain what I am doing wrong? EDIT: For clarification, this is a mapping table. There is another table called "parts" which has a column called part_id that correlates to both the parentId and childId columns in the "closure" table. The "id" column in the table above (closure) is just for the purposes of maintaining a primary key. It is not really necessary. The methods I have used to create this closure table is described in the following article: http://dirtsimple.org/2010/11/simplest-way-to-do-tree-based-queries.html EDIT2: It can have two and three hops. I will explain easier by assigning names to the items. Part 6 = Bicycle Part 7 = Gears Part 8 = Chain Part 9 = Bolt Part 10 = Nut Nut is part of Bolt. The Bolt and Nut combo exists directly within Bicycle and within Gears which is part of Bicycle. In relation to what method to use I have looked at Adjacency, Edges, Enum Paths, Closures, DAGS(networks) and the Nested Set Model. I am still trying to work out what is what, but this is an extremely complex component database where there are multiple parents and any modification to a sub-tree must propogate through the other trees. More importantly there will be insertions, deletions and tree views that I wish to avoid recursion during general use, even at the cost of database space and query time during entry.

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  • How can I construct this file tree based on what files the user is allowed to view?

    - by robert
    I have an array of files that looks like this: Array ( [0] => Array ( [type] => folder [path] => RootFolder ) [1] => Array ( [type] => file [path] => RootFolder\error.log ) [2] => Array ( [type] => folder [path] => RootFolder\test ) [3] => Array ( [type] => file [path] => RootFolder\test\asd.txt ) [4] => Array ( [type] => folder [path] => RootFolder\test\sd ) [5] => Array ( [type] => file [path] => RootFolder\test\sd\testing.txt ) ) I parse this array and create a tree like view based on the depth of the files ('/' count). It looks like this: RootFolder - error.log - test - asd.txt - sd - testing.txt What I have now is an array of filepaths the user is allowed to view. I need to take this array into account when constructing the above tree. That array looks like this: Array ( [0] => Array ( [filePath] => RootFolder\test\sd ) [1] => Array ( [filePath] => RootFolder\error.log ) ) It would be easy to do a if in_array($path, $allowed) but that won't give me the tree. Just a list of files... Another part I'm stumped on is this requirement: If the user has access to view the folder test, they then have access to all children of that folder. My idea was to simply parse the filepaths. For example, I'd confirm that RootFolder\test\sd was a directory and then create a tree based on the '/' count. Like I was doing earlier. Then, since this is a directory, I'd pull out all files within this directory and show them to the user. However, I'm having trouble converting this to working code... Any ideas?

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  • Ubuntu Touch porting: bad file tree

    - by fcole90
    I'm trying to port ubuntu touch to Samsung Galaxy S Plus but I'm finding it really difficult. The problems at first were to find a good CM rom as base, because this device is not officially supported by CM. Currently I'm using EhndroixIII but now I'm founding a lot of problems with the porting guide. In particular my file tree seems totally different from the one of the guide. For example, there is no device folder. What can I do to solve? Should I create those files? My repository is https://github.com/fcole90/utouch-sgsp.git

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  • How to code Umbraco XSLT to retrieve Nodes from unrelated tree

    - by Phil.Wheeler
    I have an Umbraco site for personal use that I want to also use as a blog. I'm trying to put together the XSLT to grab the top three posts from the nodes in the Blog tree (node id = 1063) and display these on a tab page that is incorporated into the front page. The following image illustrates the node hierarchy: With my extremely limited appreciation of XSLT, I'm unable to grab the node ID of the "Blog" id and take the 3 pages below that to display in the "Top Posts" part of my site which is found under the "Frontpage Tabs" node. All the examples I find work with the "current page", which is typically the top-level node, "Personal Site". How should I accomplish this?

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  • How to represent a tree structure in NoSQL

    - by Vlad Nicula
    I'm new to NoSQL and have been playing around with a personal project on the MEAN stack (Mongo ExpressJs AngularJs NodeJs). I'm building a document editor of sorts that manages nodes of data. Each document is actually a tree. I have a CRUD api for documents, to create new trees and a CRUD api for nodes in a given document. Right now the documents are represented as a collection that holds everything, including nodes. The children parent relationship is done by ids. So the nodes are an map by id, and each node has references to what nodes are their children. I chose this "flat" approach because it is easier to get a node by id from a document. Being used to having a relation table between nodes and documents, a relation table between nodes and children nodes I find it a bit weird that I have to save the entire "nodes" map each time I update a node. Is there a better way to represent such a data type in NoSQL?

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  • convert a logical partition to a primary partition

    - by ant2009
    Hello, Fedora 14 xfce I have the following partition setup. I would like to know how can I convert the logical partition sda6 to a primary partition. Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x1707a8a5 Device Boot Start End Blocks Id System /dev/sda1 2048 1026047 512000 83 Linux /dev/sda2 1026048 205844479 102409216 83 Linux /dev/sda3 205844480 214228991 4192256 82 Linux swap / Solaris /dev/sda4 214228992 625141759 205456384 5 Extended /dev/sda5 214231040 573562879 179665920 83 Linux /dev/sda6 573564928 625141759 25788416 7 HPFS/NTFS Filesystem Size Used Avail Use% Mounted on /dev/sda2 97G 5.0G 91G 6% / tmpfs 494M 176K 494M 1% /dev/shm /dev/sda1 485M 68M 392M 15% /boot /dev/sda5 169G 26G 135G 16% /home # partition table of /dev/sda unit: sectors /dev/sda1 : start= 2048, size= 1024000, Id=83 /dev/sda2 : start= 1026048, size=204818432, Id=83 /dev/sda3 : start=205844480, size= 8384512, Id=82 /dev/sda4 : start=214228992, size=410912768, Id= 5 /dev/sda5 : start=214231040, size=359331840, Id=83 /dev/sda6 : start=573564928, size= 51576832, Id= 7 I would like to convert sda6 to a primary partition, the reason for this it to install windows 7 starter. Many thanks for any suggestions,

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  • What is the name of this tree?

    - by Daniel
    It has a single root and each node has 0..N ordered sub-nodes . The keys represent a distinct set of paths. Two trees can only be merged if they share a common root. It needs to support, at minimum: insert, merge, enumerate paths. For this tree: The +-------+----------------+ | | | cat cow dog + +--------+ + | | | | drinks jumps moos barks + | milk the paths would be: The cat drinks milk The cow jumps The cow moos The dog barks It's a bit like a trie. What is it?

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  • Tree position terminology/naming

    - by wst
    This is a naming things question. I am processing trees (XML documents), and there are often special rules applied to nodes based on structure. It's been very difficult coming up with concise naming conventions for some cases, namely for nodes in the first position among their siblings, along with some recursive relationship: Given an arbitrary node, I want to describe its first child, and then that node's first child, and so on recursively. Given another arbitrary node, I want to describe its parent if the parent is first among its siblings, and that parent's parent if it's first, and so on recursively. Is there existing terminology to describe these tree positions? How would you name a variable or function that captures one of these cases so that it's intuitive to an unfamiliar developer trying to understand an algorithm?

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  • Creating a Logical network diagram

    - by user273284
    Im a student and I have been assigned the task of creating a logical network diagram for the following scenario There are 2 buildings, the first is the head office and the second is the branch. The data centre is in the head office, it contains domain controller, mail server, file server and a web server. it provides wired and wireless access to the staff. the branch building is new and it does not have a network. The two buildings must be connected using a VPN connection. The branch building will not have any servers but just network devices that will provide the connectivity, the users in the branch building will be connected to the head office over the VPN. I had created a diagram based on this scenario, but my teacher rejected it saying that it does not follow Cisco hierarchical Model and the servers were not placed correctly in the diagram. I just wanted some help in this matter so that I Can create my network diagram correctly. If anyone could upload a picture of how the logical diagram should be for this scenario will be helpful, any other resources would also be great.

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  • ADT-like polymorphism in Java (without altering class)

    - by ffriend
    In Haskell I can define following data type: data Tree = Empty | Leaf Int | Node Tree Tree and then write polymorphic function like this: depth :: Tree -> Int depth Empty = 0 depth (Leaf n) = 1 depth (Node l r) = 1 + max (depth l) (depth r) In Java I can emulate algebraic data types with interfaces: interface Tree {} class Empty implements Tree {} class Leaf implements Tree { int n; } class Node implements Tree { Tree l; Tree r; } But if I try to use Haskell-like polymorphism, I get an error: int depth(Empty node) { return 0; } int depth(Leaf node) { return 1; } int depth(Node node) { return 1 + Math.max(depth(node.l), depth(node.r)); // ERROR: Cannot resolve method 'depth(Tree)' } Correct way to overcome this is to put method depth() to each class. But what if I don't want to put it there? For example, method depth() may be not directly related to Tree and adding it to class would break business logic. Or, even worse, Tree may be written in 3rd party library that I don't have access to. In this case, what is the simplest way to implement ADT-like polymorpism? Just in case, for the moment I'm using following syntax, which is obviously ill-favored: int depth(Tree tree) { if (tree instanceof Empty) depth((Empty)tree) if (tree instanceof Leaf) depth((Leaf)tree); if (tree instanceof Node) depth((Node)tree); else throw new RuntimeException("Don't know how to find depth of " + tree.getClass()); }

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  • ASP.NET: Building tree picker dialog using jQuery UI and TreeView control

    - by DigiMortal
    Selecting things from dialogs and data represented as trees are very common things we see in business applications. In this posting I will show you how to use ASP.NET TreeView control and jQuery UI dialog component to build picker dialog that hosts tree data. Source code You can find working example with source code from my examples repository in GitHub. Please feel free to give me feedback about my examples. Source code repository GitHub Building dialog box As I don’t like to invent wheels then I will use jQuery UI to solve the question related to dialogs. If you are not sure how to include jQuery UI to your page then take a look at source code - GitHub also allows you to browse files without downloading them. I add some jQuery based JavaScript to my page head to get dialog and button work. <script type="text/javascript">     $(function () {         $("#dialog-form").dialog({             autoOpen: false,             modal: true         });         $("#pick-node")             .button()             .click(function () {                 $("#dialog-form").dialog("open");                 return false;             });     }); </script> Here is the mark-up of our form’s main content area. <div id="dialog-form" title="Select node">     <asp:TreeView ID="TreeView1" runat="server" ShowLines="True"          ClientIDMode="Static" HoverNodeStyle-CssClass="SelectedNode">         <Nodes>             <asp:TreeNode Text="Root" Value="Root">                 <asp:TreeNode Text="Child1" Value="Child1">                     <asp:TreeNode Text="Child1.1" Value="Child1.1" />                     <asp:TreeNode Text="Child1.2" Value="Child1.2" />                 </asp:TreeNode>                 <asp:TreeNode Text="Child2" Value="Child2">                     <asp:TreeNode Text="Child2.1" Value="Child2.1" />                     <asp:TreeNode Text="Child2.2" Value="Child2.2" />                 </asp:TreeNode>             </asp:TreeNode>         </Nodes>     </asp:TreeView>     &nbsp; </div> <button id="pick-node">Pick user</button> Notice that our mark-up is very compact for what we will achieve. If you are going to use it in some real-world application then this mark-up gets even shorter – I am sure that in most cases the data you display in TreeView comes from database or some domain specific data source. Hacking TreeView TreeView needs some little hacking to make it work as client-side component. Be warned that if you need more than I show you here you need to write a lot of JavaScript code. For more advanced scenarios I suggest you to use some jQuery based tree component. This example works for you if you need something done quickly. Number one problem is getting over the postbacks because in our scenario postbacks only screw up things. Also we need to find a way how to let our client-side code to know that something was selected from TreeView. We solve these to problems at same time: let’s move to JavaScript links. We have to make sure that when user clicks the node then information is sent to some JavaScript function. Also we have to make sure that this function returns something that is not processed by browser. My function is here. <script type="text/javascript">     function         $("#dialog-form").dialog("close");         alert("You selected: " + value + " - " + text);         return undefined;     } </script> Notice that this function returns undefined. You get the better idea why I did so if you look at server-side code that corrects NavigateUrl properties of TreeView nodes. protected override void OnPreRender(EventArgs e) {     base.OnPreRender(e);                 if (IsPostBack)         return;     SetSelectNodeUrls(TreeView1.Nodes); } private void SetSelectNodeUrls(TreeNodeCollection nodes) {     foreach (TreeNode node in nodes)     {         node.NavigateUrl = "javascript:selectNode('" + node.Value +                             "','" + node.Text + "');";         SetSelectNodeUrls(node.ChildNodes);     }        } Now we have TreeView that renders nodes the way that postback doesn’t happen anymore. Instead of postback our callback function is used and provided with selected values. In this function we are free to use node text and value as we like. Result I applied some more bells and whistles and sample data to source code to make my sample more informative. So, here is my final dialog box. Seems very basic but it is not hard to make it look more professional using style sheets. Conclusion jQuery components and ASP.NET controls have both their strong sides and weaknesses. In this posting I showed you how you can quickly produce good results when combining jQuery  and ASP.NET controls without pushing to the limits. We used simple hack to get over the postback issue of TreeView control and we made it work as client-side component that is initialized in server. You can find many other good combinations that make your UI more user-friendly and easier to use.

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  • Persisting simple tree with (Fluent-)NHibernate leads to System.InvalidCastException

    - by fudge
    Hi there, there seems to be a problem with recursive data structures and (Fluent-)NHibernate or its just me, being a complete moron... here's the tree: public class SimpleNode { public SimpleNode () { this.Children = new List<SimpleNode> (); } public virtual SimpleNode Parent { get; private set; } public virtual List<SimpleNode> Children { get; private set; } public virtual void setParent (SimpleNode parent) { parent.AddChild (this); Parent = parent; } public virtual void AddChild (SimpleNode child) { this.Children.Add (child); } public virtual void AddChildren (IEnumerable<SimpleNode> children) { foreach (var child in children) { AddChild (child); } } } the mapping: public class SimpleNodeEntity : ClassMap<SimpleNode> { public SimpleNodeEntity () { Id (x => x.Id); References (x => x.Parent).Nullable (); HasMany (x => x.Children).Not.LazyLoad ().Inverse ().Cascade.All ().KeyNullable (); } } now, whenever I try to save a node, I get this: System.InvalidCastException: Cannot cast from source type to destination type. at (wrapper dynamic-method) SimpleNode. (object,object[],NHibernate.Bytecode.Lightweight.SetterCallback) at NHibernate.Bytecode.Lightweight.AccessOptimizer.SetPropertyValues (object,object[]) at NHibernate.Tuple.Entity.PocoEntityTuplizer.SetPropertyValuesWithOptimizer (object,object[]) My setup: Mono 2.8.1 (on OSX), NHibernate 2.1.2, FluentNHibernate 1.1.0

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  • Reconstructing trees from a "fingerprint"

    - by awshepard
    I've done my SO and Google research, and haven't found anyone who has tackled this before, or at least, anyone who has written about it. My question is, given a "universal" tree of arbitrary height, with each node able to have an arbitrary number of branches, is there a way to uniquely (and efficiently) "fingerprint" arbitrary sub-trees starting from the "universal" tree's root, such that given the universal tree and a tree's fingerprint, I can reconstruct the original tree? For instance, I have a "universal" tree (forgive my poor illustrations), representing my universe of possibilities: Root / / / | \ \ ... \ O O O O O O O (Level 1) /|\/|\...................\ (Level 2) etc. I also have tree A, a rooted subtree of my universe Root / /|\ \ O O O O O / Etc. Is there a way to "fingerprint" the tree, so that given that fingerprint, and the universal tree, I could reconstruct A? I'm thinking something along the lines of a hash, a compression, or perhaps a functional/declarative construction? Big-O analysis (in time or space) is a plus. As a for-instance, a nested expression like: {{(Root)},{(1),(2),(3)},{(2,3),(1),(4,5)}...} representing the actual nodes present at each level in the tree is probably valid, but can it be done more efficiently?

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  • Advanced TSQL Tuning: Why Internals Knowledge Matters

    - by Paul White
    There is much more to query tuning than reducing logical reads and adding covering nonclustered indexes.  Query tuning is not complete as soon as the query returns results quickly in the development or test environments.  In production, your query will compete for memory, CPU, locks, I/O and other resources on the server.  Today’s entry looks at some tuning considerations that are often overlooked, and shows how deep internals knowledge can help you write better TSQL. As always, we’ll need some example data.  In fact, we are going to use three tables today, each of which is structured like this: Each table has 50,000 rows made up of an INTEGER id column and a padding column containing 3,999 characters in every row.  The only difference between the three tables is in the type of the padding column: the first table uses CHAR(3999), the second uses VARCHAR(MAX), and the third uses the deprecated TEXT type.  A script to create a database with the three tables and load the sample data follows: USE master; GO IF DB_ID('SortTest') IS NOT NULL DROP DATABASE SortTest; GO CREATE DATABASE SortTest COLLATE LATIN1_GENERAL_BIN; GO ALTER DATABASE SortTest MODIFY FILE ( NAME = 'SortTest', SIZE = 3GB, MAXSIZE = 3GB ); GO ALTER DATABASE SortTest MODIFY FILE ( NAME = 'SortTest_log', SIZE = 256MB, MAXSIZE = 1GB, FILEGROWTH = 128MB ); GO ALTER DATABASE SortTest SET ALLOW_SNAPSHOT_ISOLATION OFF ; ALTER DATABASE SortTest SET AUTO_CLOSE OFF ; ALTER DATABASE SortTest SET AUTO_CREATE_STATISTICS ON ; ALTER DATABASE SortTest SET AUTO_SHRINK OFF ; ALTER DATABASE SortTest SET AUTO_UPDATE_STATISTICS ON ; ALTER DATABASE SortTest SET AUTO_UPDATE_STATISTICS_ASYNC ON ; ALTER DATABASE SortTest SET PARAMETERIZATION SIMPLE ; ALTER DATABASE SortTest SET READ_COMMITTED_SNAPSHOT OFF ; ALTER DATABASE SortTest SET MULTI_USER ; ALTER DATABASE SortTest SET RECOVERY SIMPLE ; USE SortTest; GO CREATE TABLE dbo.TestCHAR ( id INTEGER IDENTITY (1,1) NOT NULL, padding CHAR(3999) NOT NULL,   CONSTRAINT [PK dbo.TestCHAR (id)] PRIMARY KEY CLUSTERED (id), ) ; CREATE TABLE dbo.TestMAX ( id INTEGER IDENTITY (1,1) NOT NULL, padding VARCHAR(MAX) NOT NULL,   CONSTRAINT [PK dbo.TestMAX (id)] PRIMARY KEY CLUSTERED (id), ) ; CREATE TABLE dbo.TestTEXT ( id INTEGER IDENTITY (1,1) NOT NULL, padding TEXT NOT NULL,   CONSTRAINT [PK dbo.TestTEXT (id)] PRIMARY KEY CLUSTERED (id), ) ; -- ============= -- Load TestCHAR (about 3s) -- ============= INSERT INTO dbo.TestCHAR WITH (TABLOCKX) ( padding ) SELECT padding = REPLICATE(CHAR(65 + (Data.n % 26)), 3999) FROM ( SELECT TOP (50000) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) - 1 FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) AS Data ORDER BY Data.n ASC ; -- ============ -- Load TestMAX (about 3s) -- ============ INSERT INTO dbo.TestMAX WITH (TABLOCKX) ( padding ) SELECT CONVERT(VARCHAR(MAX), padding) FROM dbo.TestCHAR ORDER BY id ; -- ============= -- Load TestTEXT (about 5s) -- ============= INSERT INTO dbo.TestTEXT WITH (TABLOCKX) ( padding ) SELECT CONVERT(TEXT, padding) FROM dbo.TestCHAR ORDER BY id ; -- ========== -- Space used -- ========== -- EXECUTE sys.sp_spaceused @objname = 'dbo.TestCHAR'; EXECUTE sys.sp_spaceused @objname = 'dbo.TestMAX'; EXECUTE sys.sp_spaceused @objname = 'dbo.TestTEXT'; ; CHECKPOINT ; That takes around 15 seconds to run, and shows the space allocated to each table in its output: To illustrate the points I want to make today, the example task we are going to set ourselves is to return a random set of 150 rows from each table.  The basic shape of the test query is the same for each of the three test tables: SELECT TOP (150) T.id, T.padding FROM dbo.Test AS T ORDER BY NEWID() OPTION (MAXDOP 1) ; Test 1 – CHAR(3999) Running the template query shown above using the TestCHAR table as the target, we find that the query takes around 5 seconds to return its results.  This seems slow, considering that the table only has 50,000 rows.  Working on the assumption that generating a GUID for each row is a CPU-intensive operation, we might try enabling parallelism to see if that speeds up the response time.  Running the query again (but without the MAXDOP 1 hint) on a machine with eight logical processors, the query now takes 10 seconds to execute – twice as long as when run serially. Rather than attempting further guesses at the cause of the slowness, let’s go back to serial execution and add some monitoring.  The script below monitors STATISTICS IO output and the amount of tempdb used by the test query.  We will also run a Profiler trace to capture any warnings generated during query execution. DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TC.id, TC.padding FROM dbo.TestCHAR AS TC ORDER BY NEWID() OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; Let’s take a closer look at the statistics and query plan generated from this: Following the flow of the data from right to left, we see the expected 50,000 rows emerging from the Clustered Index Scan, with a total estimated size of around 191MB.  The Compute Scalar adds a column containing a random GUID (generated from the NEWID() function call) for each row.  With this extra column in place, the size of the data arriving at the Sort operator is estimated to be 192MB. Sort is a blocking operator – it has to examine all of the rows on its input before it can produce its first row of output (the last row received might sort first).  This characteristic means that Sort requires a memory grant – memory allocated for the query’s use by SQL Server just before execution starts.  In this case, the Sort is the only memory-consuming operator in the plan, so it has access to the full 243MB (248,696KB) of memory reserved by SQL Server for this query execution. Notice that the memory grant is significantly larger than the expected size of the data to be sorted.  SQL Server uses a number of techniques to speed up sorting, some of which sacrifice size for comparison speed.  Sorts typically require a very large number of comparisons, so this is usually a very effective optimization.  One of the drawbacks is that it is not possible to exactly predict the sort space needed, as it depends on the data itself.  SQL Server takes an educated guess based on data types, sizes, and the number of rows expected, but the algorithm is not perfect. In spite of the large memory grant, the Profiler trace shows a Sort Warning event (indicating that the sort ran out of memory), and the tempdb usage monitor shows that 195MB of tempdb space was used – all of that for system use.  The 195MB represents physical write activity on tempdb, because SQL Server strictly enforces memory grants – a query cannot ‘cheat’ and effectively gain extra memory by spilling to tempdb pages that reside in memory.  Anyway, the key point here is that it takes a while to write 195MB to disk, and this is the main reason that the query takes 5 seconds overall. If you are wondering why using parallelism made the problem worse, consider that eight threads of execution result in eight concurrent partial sorts, each receiving one eighth of the memory grant.  The eight sorts all spilled to tempdb, resulting in inefficiencies as the spilled sorts competed for disk resources.  More importantly, there are specific problems at the point where the eight partial results are combined, but I’ll cover that in a future post. CHAR(3999) Performance Summary: 5 seconds elapsed time 243MB memory grant 195MB tempdb usage 192MB estimated sort set 25,043 logical reads Sort Warning Test 2 – VARCHAR(MAX) We’ll now run exactly the same test (with the additional monitoring) on the table using a VARCHAR(MAX) padding column: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TM.id, TM.padding FROM dbo.TestMAX AS TM ORDER BY NEWID() OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; This time the query takes around 8 seconds to complete (3 seconds longer than Test 1).  Notice that the estimated row and data sizes are very slightly larger, and the overall memory grant has also increased very slightly to 245MB.  The most marked difference is in the amount of tempdb space used – this query wrote almost 391MB of sort run data to the physical tempdb file.  Don’t draw any general conclusions about VARCHAR(MAX) versus CHAR from this – I chose the length of the data specifically to expose this edge case.  In most cases, VARCHAR(MAX) performs very similarly to CHAR – I just wanted to make test 2 a bit more exciting. MAX Performance Summary: 8 seconds elapsed time 245MB memory grant 391MB tempdb usage 193MB estimated sort set 25,043 logical reads Sort warning Test 3 – TEXT The same test again, but using the deprecated TEXT data type for the padding column: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TT.id, TT.padding FROM dbo.TestTEXT AS TT ORDER BY NEWID() OPTION (MAXDOP 1, RECOMPILE) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; This time the query runs in 500ms.  If you look at the metrics we have been checking so far, it’s not hard to understand why: TEXT Performance Summary: 0.5 seconds elapsed time 9MB memory grant 5MB tempdb usage 5MB estimated sort set 207 logical reads 596 LOB logical reads Sort warning SQL Server’s memory grant algorithm still underestimates the memory needed to perform the sorting operation, but the size of the data to sort is so much smaller (5MB versus 193MB previously) that the spilled sort doesn’t matter very much.  Why is the data size so much smaller?  The query still produces the correct results – including the large amount of data held in the padding column – so what magic is being performed here? TEXT versus MAX Storage The answer lies in how columns of the TEXT data type are stored.  By default, TEXT data is stored off-row in separate LOB pages – which explains why this is the first query we have seen that records LOB logical reads in its STATISTICS IO output.  You may recall from my last post that LOB data leaves an in-row pointer to the separate storage structure holding the LOB data. SQL Server can see that the full LOB value is not required by the query plan until results are returned, so instead of passing the full LOB value down the plan from the Clustered Index Scan, it passes the small in-row structure instead.  SQL Server estimates that each row coming from the scan will be 79 bytes long – 11 bytes for row overhead, 4 bytes for the integer id column, and 64 bytes for the LOB pointer (in fact the pointer is rather smaller – usually 16 bytes – but the details of that don’t really matter right now). OK, so this query is much more efficient because it is sorting a very much smaller data set – SQL Server delays retrieving the LOB data itself until after the Sort starts producing its 150 rows.  The question that normally arises at this point is: Why doesn’t SQL Server use the same trick when the padding column is defined as VARCHAR(MAX)? The answer is connected with the fact that if the actual size of the VARCHAR(MAX) data is 8000 bytes or less, it is usually stored in-row in exactly the same way as for a VARCHAR(8000) column – MAX data only moves off-row into LOB storage when it exceeds 8000 bytes.  The default behaviour of the TEXT type is to be stored off-row by default, unless the ‘text in row’ table option is set suitably and there is room on the page.  There is an analogous (but opposite) setting to control the storage of MAX data – the ‘large value types out of row’ table option.  By enabling this option for a table, MAX data will be stored off-row (in a LOB structure) instead of in-row.  SQL Server Books Online has good coverage of both options in the topic In Row Data. The MAXOOR Table The essential difference, then, is that MAX defaults to in-row storage, and TEXT defaults to off-row (LOB) storage.  You might be thinking that we could get the same benefits seen for the TEXT data type by storing the VARCHAR(MAX) values off row – so let’s look at that option now.  This script creates a fourth table, with the VARCHAR(MAX) data stored off-row in LOB pages: CREATE TABLE dbo.TestMAXOOR ( id INTEGER IDENTITY (1,1) NOT NULL, padding VARCHAR(MAX) NOT NULL,   CONSTRAINT [PK dbo.TestMAXOOR (id)] PRIMARY KEY CLUSTERED (id), ) ; EXECUTE sys.sp_tableoption @TableNamePattern = N'dbo.TestMAXOOR', @OptionName = 'large value types out of row', @OptionValue = 'true' ; SELECT large_value_types_out_of_row FROM sys.tables WHERE [schema_id] = SCHEMA_ID(N'dbo') AND name = N'TestMAXOOR' ; INSERT INTO dbo.TestMAXOOR WITH (TABLOCKX) ( padding ) SELECT SPACE(0) FROM dbo.TestCHAR ORDER BY id ; UPDATE TM WITH (TABLOCK) SET padding.WRITE (TC.padding, NULL, NULL) FROM dbo.TestMAXOOR AS TM JOIN dbo.TestCHAR AS TC ON TC.id = TM.id ; EXECUTE sys.sp_spaceused @objname = 'dbo.TestMAXOOR' ; CHECKPOINT ; Test 4 – MAXOOR We can now re-run our test on the MAXOOR (MAX out of row) table: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) MO.id, MO.padding FROM dbo.TestMAXOOR AS MO ORDER BY NEWID() OPTION (MAXDOP 1, RECOMPILE) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; TEXT Performance Summary: 0.3 seconds elapsed time 245MB memory grant 0MB tempdb usage 193MB estimated sort set 207 logical reads 446 LOB logical reads No sort warning The query runs very quickly – slightly faster than Test 3, and without spilling the sort to tempdb (there is no sort warning in the trace, and the monitoring query shows zero tempdb usage by this query).  SQL Server is passing the in-row pointer structure down the plan and only looking up the LOB value on the output side of the sort. The Hidden Problem There is still a huge problem with this query though – it requires a 245MB memory grant.  No wonder the sort doesn’t spill to tempdb now – 245MB is about 20 times more memory than this query actually requires to sort 50,000 records containing LOB data pointers.  Notice that the estimated row and data sizes in the plan are the same as in test 2 (where the MAX data was stored in-row). The optimizer assumes that MAX data is stored in-row, regardless of the sp_tableoption setting ‘large value types out of row’.  Why?  Because this option is dynamic – changing it does not immediately force all MAX data in the table in-row or off-row, only when data is added or actually changed.  SQL Server does not keep statistics to show how much MAX or TEXT data is currently in-row, and how much is stored in LOB pages.  This is an annoying limitation, and one which I hope will be addressed in a future version of the product. So why should we worry about this?  Excessive memory grants reduce concurrency and may result in queries waiting on the RESOURCE_SEMAPHORE wait type while they wait for memory they do not need.  245MB is an awful lot of memory, especially on 32-bit versions where memory grants cannot use AWE-mapped memory.  Even on a 64-bit server with plenty of memory, do you really want a single query to consume 0.25GB of memory unnecessarily?  That’s 32,000 8KB pages that might be put to much better use. The Solution The answer is not to use the TEXT data type for the padding column.  That solution happens to have better performance characteristics for this specific query, but it still results in a spilled sort, and it is hard to recommend the use of a data type which is scheduled for removal.  I hope it is clear to you that the fundamental problem here is that SQL Server sorts the whole set arriving at a Sort operator.  Clearly, it is not efficient to sort the whole table in memory just to return 150 rows in a random order. The TEXT example was more efficient because it dramatically reduced the size of the set that needed to be sorted.  We can do the same thing by selecting 150 unique keys from the table at random (sorting by NEWID() for example) and only then retrieving the large padding column values for just the 150 rows we need.  The following script implements that idea for all four tables: SET STATISTICS IO ON ; WITH TestTable AS ( SELECT * FROM dbo.TestCHAR ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id = ANY (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestMAX ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestTEXT ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestMAXOOR ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; All four queries now return results in much less than a second, with memory grants between 6 and 12MB, and without spilling to tempdb.  The small remaining inefficiency is in reading the id column values from the clustered primary key index.  As a clustered index, it contains all the in-row data at its leaf.  The CHAR and VARCHAR(MAX) tables store the padding column in-row, so id values are separated by a 3999-character column, plus row overhead.  The TEXT and MAXOOR tables store the padding values off-row, so id values in the clustered index leaf are separated by the much-smaller off-row pointer structure.  This difference is reflected in the number of logical page reads performed by the four queries: Table 'TestCHAR' logical reads 25511 lob logical reads 000 Table 'TestMAX'. logical reads 25511 lob logical reads 000 Table 'TestTEXT' logical reads 00412 lob logical reads 597 Table 'TestMAXOOR' logical reads 00413 lob logical reads 446 We can increase the density of the id values by creating a separate nonclustered index on the id column only.  This is the same key as the clustered index, of course, but the nonclustered index will not include the rest of the in-row column data. CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestCHAR (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestMAX (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestTEXT (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestMAXOOR (id); The four queries can now use the very dense nonclustered index to quickly scan the id values, sort them by NEWID(), select the 150 ids we want, and then look up the padding data.  The logical reads with the new indexes in place are: Table 'TestCHAR' logical reads 835 lob logical reads 0 Table 'TestMAX' logical reads 835 lob logical reads 0 Table 'TestTEXT' logical reads 686 lob logical reads 597 Table 'TestMAXOOR' logical reads 686 lob logical reads 448 With the new index, all four queries use the same query plan (click to enlarge): Performance Summary: 0.3 seconds elapsed time 6MB memory grant 0MB tempdb usage 1MB sort set 835 logical reads (CHAR, MAX) 686 logical reads (TEXT, MAXOOR) 597 LOB logical reads (TEXT) 448 LOB logical reads (MAXOOR) No sort warning I’ll leave it as an exercise for the reader to work out why trying to eliminate the Key Lookup by adding the padding column to the new nonclustered indexes would be a daft idea Conclusion This post is not about tuning queries that access columns containing big strings.  It isn’t about the internal differences between TEXT and MAX data types either.  It isn’t even about the cool use of UPDATE .WRITE used in the MAXOOR table load.  No, this post is about something else: Many developers might not have tuned our starting example query at all – 5 seconds isn’t that bad, and the original query plan looks reasonable at first glance.  Perhaps the NEWID() function would have been blamed for ‘just being slow’ – who knows.  5 seconds isn’t awful – unless your users expect sub-second responses – but using 250MB of memory and writing 200MB to tempdb certainly is!  If ten sessions ran that query at the same time in production that’s 2.5GB of memory usage and 2GB hitting tempdb.  Of course, not all queries can be rewritten to avoid large memory grants and sort spills using the key-lookup technique in this post, but that’s not the point either. The point of this post is that a basic understanding of execution plans is not enough.  Tuning for logical reads and adding covering indexes is not enough.  If you want to produce high-quality, scalable TSQL that won’t get you paged as soon as it hits production, you need a deep understanding of execution plans, and as much accurate, deep knowledge about SQL Server as you can lay your hands on.  The advanced database developer has a wide range of tools to use in writing queries that perform well in a range of circumstances. By the way, the examples in this post were written for SQL Server 2008.  They will run on 2005 and demonstrate the same principles, but you won’t get the same figures I did because 2005 had a rather nasty bug in the Top N Sort operator.  Fair warning: if you do decide to run the scripts on a 2005 instance (particularly the parallel query) do it before you head out for lunch… This post is dedicated to the people of Christchurch, New Zealand. © 2011 Paul White email: @[email protected] twitter: @SQL_Kiwi

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  • Behavior Trees and Animations

    - by Tom
    I have started working on the AI for a game, but am confused how I should handle animations. I will be using a Behavior Tree for AI behavior and Cocos2D for my game engine. Should my "PlayAnimationWalk" just be another node in the tree? Something similar to this: [Approach Player] - Play Walk animation - Move Towards player - Stop Walk animation Or should the node just update an AnimationState in the blackboard and have some type of animation handler/component reference this for which animation should be playing? This has been driving me nuts :)

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  • Tournament bracket method to put distance between teammates

    - by Fred Thomsen
    I am using a proper binary tree to simulate a tournament bracket. It's preferred any competitors in the bracket that are teammates don't meet each other until the later rounds. What is an efficient method in which I can ensure that teammates in the bracket have as much distance as possible from each other? Are there any other data structures besides a tree that would be better for this purpose? EDIT: There can be more than 2 teams represented in a bracket.

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  • How to write the Visitor Pattern for Abstract Syntax Tree in Python?

    - by bodacydo
    My collegue suggested me to write a visitor pattern to navigate the AST. Can anyone tell me more how would I start writing it? As far as I understand, each Node in AST would have visit() method (?) that would somehow get called (from where?). That about concludes my understanding. To simplify everything, suppose I have nodes Root, Expression, Number, Op and the tree looks like this: Root | Op(+) / \ / \ Number(5) \ Op(*) / \ / \ / \ Number(2) Number(444) Can anyone think of how the visitor pattern would visit this tree to produce output: 5 + 2 * 444 Thanks, Boda Cydo.

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  • ExtJs: Tree: how download then select using AJAX calls ?

    - by Olivier Pons
    Hi, Here's my goal : - open a tree - download the root nodes - expand automatically one specific node using AJAX (and loop n times here) until i find a leaf then select the leaf Here's the function that works when I declare the Tree : listeners: { load: function(n) { console.log('load(n)'); n.eachChild( function(n) { if ((n.id=='lys/2007') || (n.id=='lys/2007/08') || (n.id=='lys/2007/08/29')) { n.expand(false,false); } }); } } But if I don't know how to make it more "generic" (almost exactly like the ExtJs documentation). But they don't jump automatically to a specific node (i.e. I want no user interaction). Any idea / advice how to do this? Don't hesitate to edit my post to make it proper English :)

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  • LINQ to XML, a problem conceptualizing how the tree should look.

    - by snark
    Have you ever had one of those days when you've dug a hole but your so deep in now that the only option is to keep on digging and see where you come out? I thought just for giggles in the latest component I'm writing to use LINQ to XML because it was about time I saw what all the hooplah was about. The problem: I am making a graph component that contains series of data that get graphed and then you can apply a formula to that series and graph another series then apply a formula to that series and so on. So I figured that I would do so in 2 steps, create (and manage) an XML representaion of the series and how they relate to each other, then pass this xml to a draw engine which draws. Conceptually its a tree, with the exception of the root all child series being based upon a parent (1 parent can have many children. So I should always be adding child nodes to their parent and if I delete a node(series) then I can simply delete the series and its descendants (then draw) and voila all the messy iterating through each node finding parents and children is unneccessary. Trouble is I dont know how to represent this tree in XML i.e. the structure. My first attempt saw me programatically adding each series as siblings, which worked like a treat because I ended up with an ordered list and thus my order of rendering was maintained. I had this <Chart> <Series id="1">seriesText1</Series> <Series id="2">seriesText2</Series> <Series id="3">seriesText3</Series> <Series id="4">seriesText4</Series> </Chart> I'm in a muddle now ... how can I represent a series and a series that has children series. If some-one can give me a hint to how my tree should look (perhaps with a snippet on how to programatically add nodes to their parents) All the examples I have read usually have some container elements such as <ContactS> or <BookS> but my head says I have <series> some of them parent some of them children. Would appreciate a nudge in the right direction.

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