Resolve "Improve performance of Search API (Advanced): users scope"

app/services/search_service.rb

@@ -82,16 +82,21 @@ class SearchService
   end
 
   def redact_unauthorized_results(results_collection)
-    results = results_collection.to_a
-    permitted_results = results.select { |object| visible_result?(object) }
+    redacted_results = results_collection.reject { |object| visible_result?(object) }
 
-    redacted_results = (results - permitted_results).each_with_object({}) do |object, memo|
+    if redacted_results.any?
+      redacted_log = redacted_results.each_with_object({}) do |object, memo|
         memo[object.id] = { ability: :"read_#{object.to_ability_name}", id: object.id, class_name: object.class.name }
       end
 
-    log_redacted_search_results(redacted_results.values) if redacted_results.any?
+      log_redacted_search_results(redacted_log.values)
 
-    return results_collection.id_not_in(redacted_results.keys) if results_collection.is_a?(ActiveRecord::Relation)
+      return results_collection.id_not_in(redacted_log.keys) if results_collection.is_a?(ActiveRecord::Relation)
+    end
+
+    return results_collection if results_collection.is_a?(ActiveRecord::Relation)
+
+    permitted_results = results_collection - redacted_results
 
     Kaminari.paginate_array(
       permitted_results,

changelogs/unreleased/215711-improve-performance-of-search-api-advanced-users-scope.yml

+---
+title: Reduce redundant queries for Search API users scope.
+merge_request: 33795
+author:
+type: performance

lib/gitlab/pagination/offset_pagination.rb

@@ -19,7 +19,13 @@ module Gitlab
       private
 
       def paginate_with_limit_optimization(relation)
-        pagination_data = relation.page(params[:page]).per(params[:per_page])
+        # do not paginate relation if it is already paginated
+        pagination_data = if relation.respond_to?(:current_page) && relation.current_page == params[:page] && relation.limit_value == params[:per_page]
+                            relation
+                          else
+                            relation.page(params[:page]).per(params[:per_page])
+                          end
+
         return pagination_data unless pagination_data.is_a?(ActiveRecord::Relation)
         return pagination_data unless Feature.enabled?(:api_kaminari_count_with_limit)