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The page "RegeneratingViewsOnUpdate" has been deleted by JoanTouzet: https://wiki.apache.org/couchdb/RegeneratingViewsOnUpdate?action=diff&rev1=5&rev2=6 - #redirect Regenerating_views_on_update - = Update views on document save = - CouchDB defaults to regenerating views the first time they are accessed. This behavior is preferable in most cases as it optimizes the resource utilization on the database server. - On the other hand, in some situations the benefit of always having fast and updated views far outweigh the cost of regenerating them every time the database server receives updates. This can be achieved by supplying an updater script that calls the views when needed. - - == Example using ruby == - - === couch.ini === - Add the following line to the couch.ini file {{{ - DbUpdateNotificationProcess=/PATH/TO/view_updater.rb - }}} - - === view_updater.rb === - The following script updates the views for each tenth update made to the database or at most once every second when a lot of saves are performed {{{ - #!/usr/bin/ruby - - ################### - # CONF # - ################### - - # The smallest amount of changed documents before the views are updated - MIN_NUM_OF_CHANGED_DOCS = 10 - - # URL to the DB on the CouchDB server - URL = "http://localhost:5984"; - - # Set the minimum pause between calls to the database - PAUSE = 1 # seconds - - # One entry for each design document - # in each database - VIEWS = {"DATABASE_NAME" => ["list_of/design_documents", - "another/design_document"], - "recipes" => ["category/most_popular"], - "ingredients" => ["by/price"]} - - - ################### - # RUNTIME # - ################### - - run = true - number_of_changed_docs = {} - - threads = [] - - # Updates the views - threads << Thread.new do - - while run do - - number_of_changed_docs.each_pair do |db_name, number_of_docs| - if number_of_docs >= MIN_NUM_OF_CHANGED_DOCS - - # Reset the value - number_of_changed_docs[db_name] = 0 - - # If there are views in the database, get them - if VIEWS[db_name] - VIEWS[db_name].each do |view| - `curl #{URL}/#{db_name}/_view/#{view}?count=0` - end - end - - end - end - - # Pause before starting over again - sleep PAUSE - - end - - end - - # Receives the update notification from CouchDB - threads << Thread.new do - - while run do - - puts "Waiting for input:" - update_call = gets - - # When CouchDB exits the script gets called with - # a never ending series of nil - if update_call == nil - run = false - else - - # Get the database name out of the call data - # The data looks somethind like this: - # {"type":"updated","db":"DB_NAME"}\n - update_call =~ /\"db\":\"(\w+)\"/ - database_name = $1 - - # Set to 0 if it hasn't been initialized before - number_of_changed_docs[$1] ||= 0 - - # Add one pending changed document to the list of documents - # in the DB - number_of_changed_docs[$1] += 1 - - end - - end - - end - - # Good bye - threads.each {|thr| thr.join} - - }}} - - The view_updater.rb itself has to be made executable by CouchDB (chmod 0700?). -
