Class: Locomotive::RelationalAlgebra::SurrogateList
- Inherits:
-
Object
- Object
- Locomotive::RelationalAlgebra::SurrogateList
- Defined in:
- lib/locomotive/relational_algebra/query_information.rb
Instance Attribute Summary collapse
-
#surrogates ⇒ Object
Returns the value of attribute surrogates.
Instance Method Summary collapse
- #+(sur) ⇒ Object
- #clone ⇒ Object
- #delete_if(&lambda) ⇒ Object
- #filter_and_adapt(items) ⇒ Object
-
#initialize(hash) ⇒ SurrogateList
constructor
A new instance of SurrogateList.
- #itapp(q_0, *itbls) ⇒ Object
- #itsel(q_0) ⇒ Object
- #join ⇒ Object
- #map(&block) ⇒ Object
- #set(var, plan) ⇒ Object
Constructor Details
#initialize(hash) ⇒ SurrogateList
Returns a new instance of SurrogateList.
22 23 24 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 22 def initialize(hash) self.surrogates = hash end |
Instance Attribute Details
#surrogates ⇒ Object
Returns the value of attribute surrogates.
19 20 21 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 19 def surrogates @surrogates end |
Instance Method Details
#+(sur) ⇒ Object
31 32 33 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 31 def +(sur) SurrogateList.new(surrogates.merge(sur.surrogates)) end |
#clone ⇒ Object
156 157 158 159 160 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 156 def clone # only clone the attributes since we don't modify # the plan SurrogateList.new( surrogates.map { |k,v| [k.clone,v] }.to_hash ) end |
#delete_if(&lambda) ⇒ Object
35 36 37 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 35 def delete_if(&lambda) SurrogateList.new(self.clone.surrogates.delete_if(&lambda)) end |
#filter_and_adapt(items) ⇒ Object
162 163 164 165 166 167 168 169 170 171 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 162 def filter_and_adapt(items) item_min = items.min # we are modifying the structure itself # so we have to clone it (sideeffect) surr_new = self.delete_if do |it, itbl| !items.member?(it) end # adapt the keys surr_new.map { |k,p| [Item.new(k.id - (item_min.id - 1)), p] } end |
#itapp(q_0, *itbls) ⇒ Object
39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 39 def itapp(q_0, *itbls) if itbls.any? { |i| self.keys != i.keys } raise ITblsNotEqual, "some itbls keys are not equal" end if self.empty? and itbls.all? { |i| i.empty? } return SurrogateList.new( {} ) end c = self.first.first q1_in = self[c] qs_in = itbls.map { |itbl| itbl[c] } q1 = q1_in.plan qs = qs_in.map { |q| q.plan } cols_q1, itbls_q1 = q1_in.column_structure, q1_in.surrogates ord, ord_, item_, item__ = Iter.new(2), Iter.new(4), Iter.new(3), Item.new(3) # (1) q1_ = q1.attach(AttachItem.new(ord, RAtomic.new(1, RNat.type))) q = qs.zip(2..qs.size+1).reduce(q1_) do |p1,p2| p1.union( p2.first.attach(AttachItem.new(ord, RAtomic.new(p2.last, RNat.type)))) end.row_num(item_, [], [Iter.new(1), ord, Pos.new(1)]) #(2) c_new = Iter.new(5) q_ = q_0.project( ord => [ord_], item_ => [item__], c => [c_new] ). theta_join(q, [Equivalence.new(ord_, ord), Equivalence.new(c_new, Iter.new(1))] ). project( { item__ => [Iter.new(1)], Pos.new(1) => [Pos.new(1)], item_ => itbls_q1.keys }. merge( (cols_q1 - itbls_q1.keys).items.collect do |col| [col, [col]] end.to_hash) ) # (3) itbl_ = q1_in.surrogates.itapp(q, *qs_in.map { |q| q.surrogates }) # (4) itbl__ = self.delete_if { |k,v| k == c}. itapp(q_0, *itbls.map { |i| i.delete_if { |k,v| k == c} }) # (5) SurrogateList.new( { c => QueryInformationNode.new( q_, cols_q1, itbl_) } ) + itbl__ end |
#itsel(q_0) ⇒ Object
93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 93 def itsel(q_0) return SurrogateList.new({}) if self.empty? c = self.first.first cols, itbls, q = self[c].column_structure, self[c].surrogates, self[c].plan c_ = (self.keys + cols.items).max.inc # (1) q_ = q.equi_join(q_0.project( c => [c_]), Iter.new(1), c_). project( [Iter.new(1), Pos.new(1)] + cols.items ) itbls_ = itbls.itsel(q_) itbls__ = self.delete_if { |k,v| k == c }.itsel(q_0) SurrogateList.new( { c => QueryInformationNode.new(q_, cols, itbls_) }. merge( itbls__.to_a.to_hash ) ) end |
#join ⇒ Object
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 112 def join itbls = surrogates.to_a itbls.rest.reduce(itbls.first.last) do |qi,surr| # the query_information node qin_j = surr.last cols_j = surr.last.column_structure itbls_j = surr.last.surrogates cols_c = qi.column_structure itbls_c = qi.surrogates # adapt cols cols_j_ = cols_j.clone cols_j_.items.each { |i| i.inc!(qi.column_structure.count) } # adapt itbls itbls_j_ = itbls_j.map { |k,q| [k.inc(qi.column_structure.count), q] } # calculate new plan q_j = qin_j.plan.project({ Iter.new(1) => [Iter.new(2)], Pos.new(1) => [Pos.new(2)] }. merge( cols_j.items.zip(cols_j_.items). map do |old,new| [old,[new]] end.to_hash)) q_ = q_j.theta_join(qi.plan, [Equivalence.new(Iter.new(2), Iter.new(1)), Equivalence.new(Pos.new(2), Pos.new(1))]). project([Iter.new(1), Pos.new(1)] + cols_c.items + cols_j_.items) QueryInformationNode.new(q_, cols_c + cols_j_, itbls_c + itbls_j_) end end |
#map(&block) ⇒ Object
26 27 28 29 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 26 def map(&block) SurrogateList.new( surrogates.map(&block).to_hash) end |
#set(var, plan) ⇒ Object
148 149 150 151 152 153 154 |
# File 'lib/locomotive/relational_algebra/query_information.rb', line 148 def set(var, plan) self.map do |item, itbl| [item,QueryInformationNode.new(itbl.plan.set(var, plan), itbl.column_structure, itbl.surrogates.set(var,plan))] end end |