improving the runtime of migrations

Daniela Feitosa
1 parent 4d7446b1
Showing 5 changed files with 16 additions and 9 deletions Show diff stats
db/migrate/20140708121356_index_articles_filtered_fields.rb
db/migrate/20140709212646_add_spam_comments_counter_cache_to_articles.rb
db/migrate/20140709224246_create_real_relation_between_article_and_author.rb
db/migrate/20140724180943_add_index_to_blog_posts_sort.rb
db/schema.rb
 class IndexArticlesFilteredFields < ActiveRecord::Migration
   def self.up
     %w[articles article_versions].each do |table|
-      add_index table, [:path]
-      add_index table, [:path, :profile_id]
+      add_index table.to_sym, [:path]
+      add_index table.to_sym, [:path, :profile_id]
     end
     add_index :articles, [:type]
     add_index :articles, [:type, :parent_id]
@@ -2,7 +2,10 @@ class AddSpamCommentsCounterCacheToArticles &lt; ActiveRecord::Migration
   def self.up
     add_column :articles, :spam_comments_count, :integer, :default => 0
     add_column :article_versions, :spam_comments_count, :integer, :default => 0
-    execute "update articles set spam_comments_count = (select count(*) from comments where comments.source_id = articles.id and comments.source_type = 'Article' and comments.spam = 't');"
+
+    execute("SELECT comments.source_id as source_id, count(comments.id) as comments_count FROM comments LEFT OUTER JOIN articles ON articles.id = source_id WHERE comments.source_type = 'Article' AND comments.spam = 't' GROUP BY comments.source_id;").each do |data|
+      execute("UPDATE articles SET spam_comments_count = '#{data['comments_count']}' WHERE id = #{data['source_id']}")
+    end
   end
   def self.down
@@ -4,8 +4,10 @@ class CreateRealRelationBetweenArticleAndAuthor &lt; ActiveRecord::Migration
     add_column :article_versions, :author_id, :integer
     # Set article's author as the first version's last_changed_by_id.
-    execute "update articles set author_id = (select article_versions.last_changed_by_id from article_versions where article_versions.article_id = articles.id and article_versions.version = 1 limit 1)"
-  end
+    execute("UPDATE article_versions SET author_id = last_changed_by_id")
+
+    execute("UPDATE articles SET author_id = article_versions.author_id FROM article_versions WHERE article_versions.article_id = articles.id AND article_versions.version = 1")
+ end
   def self.down
     remove_column :articles, :author_id
 class AddIndexToBlogPostsSort < ActiveRecord::Migration
   def self.up
      %w[articles article_versions].each do |table|
-      add_index table, [:published_at, :id]
+      add_index table.to_sym, [:published_at, :id]
     end
  end
   def self.down
      %w[articles article_versions].each do |table|
-      remove_index table, [:published_at, :id]
+      remove_index table.to_sym, [:published_at, :id]
     end
   end
 end
-# This file is auto-generated from the current state of the database. Instead of editing this file,
+# This file is auto-generated from the current state of the database. Instead of editing this file, 
 # please use the migrations feature of Active Record to incrementally modify your database, and
 # then regenerate this schema definition.
 #
@@ -9,7 +9,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
-ActiveRecord::Schema.define(:version => 20140709224246) do
+ActiveRecord::Schema.define(:version => 20140724180943) do
   create_table "abuse_reports", :force => true do |t|
     t.integer  "reporter_id"
@@ -100,6 +100,7 @@ ActiveRecord::Schema.define(:version =&gt; 20140709224246) do
   add_index "article_versions", ["article_id"], :name => "index_article_versions_on_article_id"
   add_index "article_versions", ["path", "profile_id"], :name => "index_article_versions_on_path_and_profile_id"
   add_index "article_versions", ["path"], :name => "index_article_versions_on_path"
+  add_index "article_versions", ["published_at", "id"], :name => "index_article_versions_on_published_at_and_id"
   create_table "articles", :force => true do |t|
     t.string   "name"
@@ -154,6 +155,7 @@ ActiveRecord::Schema.define(:version =&gt; 20140709224246) do
   add_index "articles", ["path", "profile_id"], :name => "index_articles_on_path_and_profile_id"
   add_index "articles", ["path"], :name => "index_articles_on_path"
   add_index "articles", ["profile_id"], :name => "index_articles_on_profile_id"
+  add_index "articles", ["published_at", "id"], :name => "index_articles_on_published_at_and_id"
   add_index "articles", ["slug"], :name => "index_articles_on_slug"
   add_index "articles", ["translation_of_id"], :name => "index_articles_on_translation_of_id"
   add_index "articles", ["type", "parent_id"], :name => "index_articles_on_type_and_parent_id"
1	class AddIndexToBlogPostsSort < ActiveRecord::Migration	1	class AddIndexToBlogPostsSort < ActiveRecord::Migration
2	def self.up	2	def self.up
3	%w[articles article_versions].each do \|table\|	3	%w[articles article_versions].each do \|table\|
4	- add_index table, [:published_at, :id]	4	+ add_index table.to_sym, [:published_at, :id]
5	end	5	end
6	end	6	end
7		7
8	def self.down	8	def self.down
9	%w[articles article_versions].each do \|table\|	9	%w[articles article_versions].each do \|table\|
10	- remove_index table, [:published_at, :id]	10	+ remove_index table.to_sym, [:published_at, :id]
11	end	11	end
12	end	12	end
13	end	13	end