Class: Veritas::Optimizer::Algebra::Projection::UnionOperand

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

Overview

Optimize when the operand is a Union

Constant Summary

Constants inherited from Veritas::Optimizer

Noop, VERSION

Instance Attribute Summary

Attributes inherited from Relation::Operation::Unary

#header

Attributes included from Function::Unary

#operand

Attributes inherited from Veritas::Optimizer

#operation

Instance Method Summary collapse

Methods inherited from Relation::Operation::Unary

#initialize

Methods included from Function::Unary

#initialize

Methods inherited from Veritas::Optimizer

chain, #initialize

Constructor Details

This class inherits a constructor from Veritas::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)


52
53
54
# File 'lib/veritas/optimizer/algebra/projection.rb', line 52

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

#optimizeSet

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)


61
62
63
# File 'lib/veritas/optimizer/algebra/projection.rb', line 61

def optimize
  wrap_left.union(wrap_right)
end