class Axiom::Optimizer::Algebra::Join
Abstract base class representing Join
optimizations
Constants
- CONTRADICTION
Private Instance Methods
join_key()
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Return the key to join the operations with
@return [Header]
@todo find a minimal key from the header
@api private
# File lib/axiom/optimizer/algebra/join.rb, line 21 def join_key operation.join_header end
materialized_predicate()
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Return a predicate that matches every tuple in the materialized operand
@return [Function]
@api private
# File lib/axiom/optimizer/algebra/join.rb, line 30 def materialized_predicate matching_projection.reduce(CONTRADICTION) do |accumulator, element| accumulator.or(element.predicate) end.optimize end