Class: Veritas::Optimizer::Relation::Operation::Limit::ZeroLimit

Inherits:
Veritas::Optimizer::Relation::Operation::Limit show all
Defined in:
lib/veritas/optimizer/relation/operation/limit.rb

Overview

Optimize when the limit is zero

Constant Summary

Constants inherited from Veritas::Optimizer

Noop, VERSION

Instance Attribute Summary

Attributes inherited from Unary

#header

Attributes included from Function::Unary

#operand

Attributes inherited from Veritas::Optimizer

#operation

Instance Method Summary collapse

Methods inherited from 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 limit is zero

Returns:

  • (Boolean) 


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# File 'lib/veritas/optimizer/relation/operation/limit.rb', line 30

def optimizable?
  limit.zero?
end

#optimize ⇒ Relation::Empty

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 Limit with a limit of zero is empty

Returns:

  • (Relation::Empty) 


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# File 'lib/veritas/optimizer/relation/operation/limit.rb', line 39

def optimize
  operation = self.operation
  Veritas::Relation::Empty.new(operation.header, operation)
end