1 files changed, 42 insertions, 0 deletions
diff --git a/lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb b/lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb
new file mode 100644
index 00000000000..b12c33d6e51
--- /dev/null
+++ b/lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Pagination
+    module Keyset
+      module InOperatorOptimization
+        module Strategies
+          class RecordLoaderStrategy
+            RECORDS_COLUMN = 'records'
+
+            def initialize(finder_query, model, order_by_columns)
+              @finder_query = finder_query
+              @order_by_columns = order_by_columns
+              @table_name = model.table_name
+            end
+
+            def initializer_columns
+              ["NULL::#{table_name} AS #{RECORDS_COLUMN}"]
+            end
+
+            def columns
+              query = finder_query
+                .call(*order_by_columns.array_lookup_expressions_by_position(QueryBuilder::RECURSIVE_CTE_NAME))
+                .select("#{table_name}")
+                .limit(1)
+
+              ["(#{query.to_sql})"]
+            end
+
+            def final_projections
+              ["(#{RECORDS_COLUMN}).*"]
+            end
+
+            private
+
+            attr_reader :finder_query, :order_by_columns, :table_name
+          end
+        end
+      end
+    end
+  end
+end