Class: Veritas::Optimizer::Algebra::Join::RightMaterializedOperand

Inherits:

Veritas::Optimizer::Algebra::Join

• Object
• Veritas::Optimizer
• Relation::Operation::Binary
• Relation::Operation::Combination
• Veritas::Optimizer::Algebra::Join
• Veritas::Optimizer::Algebra::Join::RightMaterializedOperand

Defined in:

lib/veritas/optimizer/algebra/join.rb

Overview

Optimize when the right operand is materialized

Constant Summary

Constants inherited from Veritas::Optimizer::Algebra::Join

CONTRADICTION

Constants inherited from Veritas::Optimizer

Noop, VERSION

Instance Attribute Summary

Attributes included from Function::Binary

#left, #right

Attributes inherited from Veritas::Optimizer

#operation

Instance Method Summary

• #optimizable? ⇒ Boolean private

  Test if the right operand is materialized.

• #optimize ⇒ Algebra::Join private

  Return the join of the left and right with the left restricted.

Methods included from Function::Binary

#initialize

Methods inherited from Veritas::Optimizer

chain, #initialize

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 right operand is materialized

Returns:

• (Boolean)

# File 'lib/veritas/optimizer/algebra/join.rb', line 132

def optimizable?
  right.materialized? && ! left_matching_right?
end

#optimize ⇒ Algebra::Join

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.

Return the join of the left and right with the left restricted

Returns:

• (Algebra::Join)

# File 'lib/veritas/optimizer/algebra/join.rb', line 141

def optimize
  left.restrict { materialized_predicate }.join(right)
end