ruby 50 lines · 1 tab

Bulk operations with ActiveRecord import

Alex Kumar Jan 2026

1 tab

require 'activerecord-import'

class BulkImportPostsService
  BATCH_SIZE = 1000

  def initialize(csv_file_path)
    @csv_file_path = csv_file_path
  end

  def call
    posts = []
    imported_count = 0

    CSV.foreach(@csv_file_path, headers: true) do |row|
      posts << Post.new(
        title: row['title'],
        body: row['body'],
        author_id: row['author_id'],
        published_at: row['published_at']
      )

      if posts.size >= BATCH_SIZE
        imported_count += import_batch(posts)
        posts = []
      end
    end

    # Import remaining posts
    imported_count += import_batch(posts) if posts.any?

    Result.success(imported_count: imported_count)
  rescue StandardError => e
    Rails.logger.error("Bulk import failed: #{e.message}")
    Result.failure(error: e.message)
  end

  private

  def import_batch(posts)
    Post.import(
      posts,
      validate: false,
      on_duplicate_key_update: {
        conflict_target: [:id],
        columns: [:title, :body, :updated_at]
      }
    )
    posts.size
  end
end

1 file · ruby Explain with highlit

Inserting thousands of records one-by-one is prohibitively slow due to the overhead of individual INSERT statements. The activerecord-import gem provides bulk insert capabilities that compile multiple records into a single multi-row INSERT, dramatically improving throughput. I use this for data imports, batch processing, or seeding test environments. The gem supports validations, callbacks (optionally), and conflict resolution strategies like on_duplicate_key_update. For maximum performance, I disable validations and callbacks when data is already trusted. The trade-off is that bulk operations bypass some ActiveRecord conveniences like after_create callbacks, so I handle those concerns separately if needed. Monitoring insertion rates helps identify when bulk operations are worth the complexity.

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