Class: Gitlab::Pagination::Keyset::InOperatorOptimization::Strategies::RecordLoaderStrategy

Inherits:
Object
  • Object
show all
Defined in:
lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb

Constant Summary collapse

RECORDS_COLUMN =
'records'

Instance Method Summary collapse

Constructor Details

#initialize(finder_query, model, order_by_columns) ⇒ RecordLoaderStrategy

Returns a new instance of RecordLoaderStrategy.



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# File 'lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb', line 11

def initialize(finder_query, model, order_by_columns)
  verify_order_by_attributes_on_model!(model, order_by_columns)

  @finder_query = finder_query
  @order_by_columns = order_by_columns
  @table_name = model.table_name
  @model = model
end

Instance Method Details

#columnsObject



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# File 'lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb', line 24

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

#final_projectionsObject



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# File 'lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb', line 33

def final_projections
  if @model.default_select_columns.is_a?(Array)
    @model.default_select_columns.map { |column| "(#{RECORDS_COLUMN}).#{column.name}" }
  else
    ["(#{RECORDS_COLUMN}).*"]
  end
end

#initializer_columnsObject



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# File 'lib/gitlab/pagination/keyset/in_operator_optimization/strategies/record_loader_strategy.rb', line 20

def initializer_columns
  ["NULL::#{table_name} AS #{RECORDS_COLUMN}"]
end