```ruby
# frozen_string_literal: true

module GobiertoData
  class DatasetMetaSerializer < DatasetSerializer
    has_many :queries
    has_many :visualizations

    attribute :data_summary do
      {
        number_of_rows: object.rails_model.count
      }
    end

    attribute :columns do
      object.rails_model.column_names
    end

    attribute :data_preview do
      object.rails_model.first(50)
    end
  end
end
```

Update datasets columns attribute in meta to include data types
user
```ruby
# frozen_string_literal: true

module GobiertoData
  class DatasetMetaSerializer < DatasetSerializer
    has_many :queries
    has_many :visualizations

    attribute :data_summary do
      {
        number_of_rows: object.rails_model.count
      }
    end

    attribute :columns do
      object.rails_model.columns.inject({}) do |columns, column|
        columns.update(
          column.name => column.type
        )
      end
    end

    attribute :data_preview do
      object.rails_model.first(50)
    end
  end
end
```
assistant