1 files changed, 44 insertions, 0 deletions
diff --git a/lib/active_record/batches.rb b/lib/active_record/batches.rb
new file mode 100644
index 000000000..55d29e52e
--- /dev/null
+++ b/lib/active_record/batches.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module Batches
+    def pluck_each(*column_names)
+      relation = self
+
+      options = column_names.extract_options!
+
+      flatten     = column_names.size == 1
+      batch_limit = options[:batch_limit] || 1_000
+      order       = options[:order] || :asc
+
+      column_names.unshift(primary_key)
+
+      relation = relation.reorder(batch_order(order)).limit(batch_limit)
+      relation.skip_query_cache!
+
+      batch_relation = relation
+
+      loop do
+        batch = batch_relation.pluck(*column_names)
+
+        break if batch.empty?
+
+        primary_key_offset = batch.last[0]
+
+        batch.each do |record|
+          if flatten
+            yield record[1]
+          else
+            yield record[1..-1]
+          end
+        end
+
+        break if batch.size < batch_limit
+
+        batch_relation = relation.where(
+          predicate_builder[primary_key, primary_key_offset, order == :desc ? :lt : :gt]
+        )
+      end
+    end
+  end
+end