1 files changed, 38 insertions, 0 deletions
diff --git a/db/post_migrate/20180306164012_add_path_index_to_redirect_routes.rb b/db/post_migrate/20180306164012_add_path_index_to_redirect_routes.rb
new file mode 100644
index 00000000000..d6fb4f06695
--- /dev/null
+++ b/db/post_migrate/20180306164012_add_path_index_to_redirect_routes.rb
@@ -0,0 +1,38 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddPathIndexToRedirectRoutes < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+  disable_ddl_transaction!
+
+  INDEX_NAME = 'index_redirect_routes_on_path_unique_text_pattern_ops'
+
+  # Indexing on LOWER(path) varchar_pattern_ops speeds up the LIKE query in
+  # RedirectRoute.matching_path_and_descendants
+  #
+  # This same index is also added in the `ReworkRedirectRoutesIndexes` so this
+  # is a no-op in most cases. But this migration is also called from the
+  # `setup_postgresql.rake` task when setting up a new database, in which case
+  # we want to create the index.
+  def up
+    return unless Gitlab::Database.postgresql?
+
+    disable_statement_timeout
+
+    unless index_exists_by_name?(:redirect_routes, INDEX_NAME)
+      execute("CREATE UNIQUE INDEX CONCURRENTLY #{INDEX_NAME} ON redirect_routes (lower(path) varchar_pattern_ops);")
+    end
+  end
+
+  def down
+    # Do nothing in the DOWN. Since the index above is originally created in the
+    # `ReworkRedirectRoutesIndexes`. This migration wouldn't have actually
+    # created any new index.
+    #
+    # This migration is only here to be called form `setup_postgresql.rake` so
+    # any newly created database would have this index.
+  end
+end