Class: Veritas::Optimizer::Algebra::Join::DisjointHeaders

Inherits:

Veritas::Optimizer::Algebra::Join

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

Defined in:

lib/veritas/optimizer/algebra/join.rb

Overview

Optimize when operands' headers are disjoint

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 operands' headers are disjoint.

• #optimize ⇒ Algebra::Product private

  A Join with disjoint headers is a Product.

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 operands' headers are disjoint

# File 'lib/veritas/optimizer/algebra/join.rb', line 65

def optimizable?
  (left.header & right.header).none?
end

#optimize ⇒ Algebra::Product

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.

A Join with disjoint headers is a Product

# File 'lib/veritas/optimizer/algebra/join.rb', line 74

def optimize
  left.product(right)
end