Class: Axiom::Optimizer::Algebra::Projection::UnionOperand

Inherits:
Axiom::Optimizer::Algebra::Projection show all
Defined in:
lib/axiom/optimizer/algebra/projection.rb

Overview

Optimize when the operand is a Union

Constant Summary

Constants inherited from Axiom::Optimizer

Identity, VERSION

Instance Attribute Summary

Attributes inherited from Relation::Operation::Unary

#header

Attributes included from Function::Unary

#operand

Attributes inherited from Axiom::Optimizer

#operation

Instance Method Summary collapse

Methods inherited from Relation::Operation::Unary

#initialize

Methods included from Function::Unary

#initialize

Methods inherited from Axiom::Optimizer

chain, #initialize

Constructor Details

This class inherits a constructor from Axiom::Optimizer::Relation::Operation::Unary

Instance Method Details

#optimizable? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Test if the operand is a Union

Returns:

  • (Boolean) 


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# File 'lib/axiom/optimizer/algebra/projection.rb', line 120

def optimizable?
  operand.kind_of?(Axiom::Algebra::Union)
end

#optimize ⇒ Set

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Wrap each operand in the Union in a Projection

Returns:

  • (Set) 


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# File 'lib/axiom/optimizer/algebra/projection.rb', line 129

def optimize
  wrap_left.union(wrap_right)
end