Class: Locomotive::RelationalAlgebra::QueryInformationNode

Inherits:
Object
  • Object
show all
Defined in:
lib/locomotive/relational_algebra/query_information.rb,
lib/locomotive/relational_algebra/query_information.rb

Overview

Forward declaration

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(plan, cs_structure, surrogates = nil, side_effects = nil, methods = {}) ⇒ QueryInformationNode

Returns a new instance of QueryInformationNode.



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 478

def initialize(plan, cs_structure, surrogates=nil, side_effects=nil, methods={})
  self.plan,
  self.column_structure,
  self.surrogates,
  self.side_effects = plan, to_cs_structure(cs_structure),
                      to_surrogates(surrogates),
                      to_side_effects(side_effects)
  
  unless self.plan.schema.attributes?(self.column_structure.items) then 
    raise StandardError, "Queryplan doesn't contain all attributes of" \
                         " #{self.column_structure.items.inspect}"
  end
  self.methods = methods
end

Instance Attribute Details

#column_structure ⇒ Object

Returns the value of attribute column_structure.



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 466

def column_structure
  @column_structure
end

#methods ⇒ Object

Returns the value of attribute methods.



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 466

def methods
  @methods
end

#plan ⇒ Object

Returns the value of attribute plan.



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 466

def plan
  @plan
end

#side_effects ⇒ Object

Returns the value of attribute side_effects.



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 466

def side_effects
  @side_effects
end

#surrogates ⇒ Object

Returns the value of attribute surrogates.



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 466

def surrogates
  @surrogates
end

Instance Method Details

#clone ⇒ Object 



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 520

def clone
  QueryInformationNode.new(plan,
                           column_structure.clone,
                           surrogates.clone)
end

#frag ⇒ Object 



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# File 'lib/locomotive/relational_algebra/query_information.rb', line 493

def frag 
  itbls_hash = {}

  column_structure.
    zip(1..column_structure.count).each do |c, i|

    cols_c = column_structure[i-1].column_structure.adapt
    itbls_c = surrogates.filter_and_adapt(c.items)

    q_c = plan.project({ Iter.new(1) => [Iter.new(1)],
                         Pos.new(1)  => [Pos.new(1)] }.
                       merge(
                         c.items.zip(cols_c.items).
                           map do |old,new|
                             [old,[new]]
                         end.to_hash))
  
    itbls_hash = itbls_hash.merge(
                    { Item.new(i) => QueryInformationNode.new(
                                       q_c,
                                       cols_c,
                                       itbls_c) })
  end

  SurrogateList.new( itbls_hash )
end