Change hashtags to preserve first-used casing (#11416)

2 files changed, 17 insertions, 3 deletions

diff --git a/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb b/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb
new file mode 100644
index 000000000..6fa8c0ec4
--- /dev/null
+++ b/db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb
@@ -0,0 +1,15 @@
+class AddCaseInsensitiveIndexToTags < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def up
+    safety_assured { execute 'CREATE UNIQUE INDEX CONCURRENTLY index_tags_on_name_lower ON tags (lower(name))' }
+    remove_index :tags, name: 'index_tags_on_name'
+    remove_index :tags, name: 'hashtag_search_index'
+  end
+
+  def down
+    add_index :tags, :name, unique: true, algorithm: :concurrently
+    safety_assured { execute 'CREATE INDEX CONCURRENTLY hashtag_search_index ON tags (name text_pattern_ops)' }
+    remove_index :tags, name: 'index_tags_on_name_lower'
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6319dd932..1847305c7 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_07_15_164535) do
+ActiveRecord::Schema.define(version: 2019_07_26_175042) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -652,8 +652,7 @@ ActiveRecord::Schema.define(version: 2019_07_15_164535) do
     t.string "name", default: "", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.index "lower((name)::text) text_pattern_ops", name: "hashtag_search_index"
-    t.index ["name"], name: "index_tags_on_name", unique: true
+    t.index "lower((name)::text)", name: "index_tags_on_name_lower", unique: true
   end
 
   create_table "tombstones", force: :cascade do |t|