Class: ActiveFacts::Generators::Transform::DataVault
- Inherits:
-
Object
- Object
- ActiveFacts::Generators::Transform::DataVault
- Defined in:
- lib/activefacts/generators/transform/datavault.rb
Instance Method Summary collapse
- #assert_date_time ⇒ Object
- #assert_record_source ⇒ Object
- #assert_value_type(name, supertype = nil) ⇒ Object
- #classify_satellite_references(table) ⇒ Object
- #classify_tables ⇒ Object
- #create_one_to_many(one, many, predicate_1 = 'has', predicate_2 = 'is of', one_adj = nil) ⇒ Object
- #create_satellite(table, satellite_name, references) ⇒ Object
-
#create_two_role_identifier(r1, r2) ⇒ Object
Create a PresenceConstraint with two roles, marked as preferred_identifier.
- #detect_required_surrogates ⇒ Object
- #generate(out = $stdout) ⇒ Object
-
#initialize(vocabulary, *options) ⇒ DataVault
constructor
A new instance of DataVault.
- #inject_required_surrogates ⇒ Object
- #lift_role_to_link(ref, table_role) ⇒ Object
- #trace_table_classifications ⇒ Object
Constructor Details
#initialize(vocabulary, *options) ⇒ DataVault
Returns a new instance of DataVault.
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# File 'lib/activefacts/generators/transform/datavault.rb', line 27 def initialize(vocabulary, *) @vocabulary = vocabulary @constellation = vocabulary.constellation end |
Instance Method Details
#assert_date_time ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 160 def assert_date_time assert_value_type('Date Time') end |
#assert_record_source ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 156 def assert_record_source assert_value_type('Record Source', assert_value_type('String')) end |
#assert_value_type(name, supertype = nil) ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 151 def assert_value_type name, supertype = nil @vocabulary.valid_value_type_name(name) || @constellation.ValueType(:vocabulary => @vocabulary, :name => name, :supertype => supertype, :concept => :new) end |
#classify_satellite_references(table) ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 89 def classify_satellite_references table = table.identifier_columns.map{|c| c.references.first}.uniq = table.columns.map{|c| c.references[0]}.uniq - # Skip this table if no satellite data is needed # REVISIT: Needed anyway for a link? if .size == 0 return nil end satellites = .inject({}) do |hash, ref| # Extract the declared satellite name, or use just "satellite" satellite_subname = ref.fact_type.internal_presence_constraints.map do |pc| next if !pc.max_frequency || pc.max_frequency > 1 # Not a Uniqueness Constraint next if pc.role_sequence.all_role_ref.size > 1 # Covers more than one role next if pc.role_sequence.all_role_ref.single.role.object_type != table # Not a unique attribute pc.concept.all_concept_annotation.map do |ca| if ca.mapping_annotation =~ /^satellite */ ca.mapping_annotation.sub(/^satellite +/, '') else nil end end end.flatten.compact.uniq[0] || table.name satellite_name = satellite_subname (hash[satellite_name] ||= []) << ref hash end trace :datavault, "#{table.name} satellites are #{satellites.inspect}" satellites end |
#classify_tables ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 32 def classify_tables initial_tables = @vocabulary.tables non_reference_tables = initial_tables.reject do |table| table.concept.all_concept_annotation.detect{|ca| ca.mapping_annotation == 'static'} or !table.is_a?(ActiveFacts::Metamodel::EntityType) end @reference_tables = initial_tables-non_reference_tables @link_tables, @hub_tables = non_reference_tables.partition do |table| = table.identifier_columns.map{|c| c.references.first}.uniq # Which identifying_references are played by other tables? ir_tables = .select do |r| table_referred_to = r.to # I have no examples of multi-level absorption, but it's possible, so loop while av = table_referred_to.absorbed_via table_referred_to = av.from end table_referred_to.is_table end ir_tables.size > 1 end trace_table_classifications end |
#create_one_to_many(one, many, predicate_1 = 'has', predicate_2 = 'is of', one_adj = nil) ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 122 def create_one_to_many(one, many, predicate_1 = 'has', predicate_2 = 'is of', one_adj = nil) # Create a fact type fact_type = @constellation.FactType(:concept => :new) one_role = @constellation.Role(:concept => :new, :fact_type => fact_type, :ordinal => 0, :object_type => one) many_role = @constellation.Role(:concept => :new, :fact_type => fact_type, :ordinal => 1, :object_type => many) # Create two readings reading2 = @constellation.Reading(:fact_type => fact_type, :ordinal => 0, :role_sequence => [:new], :text => "{0} #{predicate_2} {1}") @constellation.RoleRef(:role_sequence => reading2.role_sequence, :ordinal => 0, :role => many_role) @constellation.RoleRef(:role_sequence => reading2.role_sequence, :ordinal => 1, :role => one_role, :leading_adjective => one_adj) reading1 = @constellation.Reading(:fact_type => fact_type, :ordinal => 1, :role_sequence => [:new], :text => "{0} #{predicate_1} {1}") @constellation.RoleRef(:role_sequence => reading1.role_sequence, :ordinal => 0, :role => one_role, :leading_adjective => one_adj) @constellation.RoleRef(:role_sequence => reading1.role_sequence, :ordinal => 1, :role => many_role) one_id = @constellation.PresenceConstraint( :concept => :new, :vocabulary => @vocabulary, :name => one.name+'HasOne'+many.name, :role_sequence => [:new], :is_mandatory => true, :min_frequency => 1, :max_frequency => 1, :is_preferred_identifier => false ) @constellation.RoleRef(:role_sequence => one_id.role_sequence, :ordinal => 0, :role => many_role) one_role end |
#create_satellite(table, satellite_name, references) ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 204 def create_satellite(table, satellite_name, references) satellite_name = satellite_name.words.titlewords*' '+' SAT' # Create a new entity type with record-date fields in its identifier trace :datavault, "Creating #{satellite_name} with #{references.size} references" satellite = @constellation.EntityType(:vocabulary => @vocabulary, :name => "#{satellite_name}", :concept => [:new, :implication_rule => "datavault"]) satellite.definitely_table table_role = create_one_to_many(table, satellite) date_time = assert_date_time date_time_role = create_one_to_many(date_time, satellite, 'is of', 'was loaded at', 'load') create_two_role_identifier(table_role, date_time_role) record_source = assert_record_source record_source.length = 64 record_source_role = create_one_to_many(record_source, satellite, 'is of', 'was loaded from') # Move all roles across to it from the parent table. references.each do |ref| trace :datavault, "Moving #{ref} across to #{table.name}_#{satellite_name}" do table_role = ref.fact_type.all_role.detect{|r| r.object_type == table} if table_role remote_table = ref.to while remote_table && remote_table.absorbed_via absorbed_into = remote_table.absorbed_via.from remote_table = absorbed_into end if @hub_tables.include?(remote_table) lift_role_to_link(ref, table_role) else # Reassign the role player to the satellite: table_role.object_type = satellite end else #debugger # Bum, the crappy Reference object bites again. $stderr.puts "REVISIT: Can't move the objectified role for #{ref.inspect}. This column will remain in the hub instead of moving to the satellite" end end end satellite end |
#create_two_role_identifier(r1, r2) ⇒ Object
Create a PresenceConstraint with two roles, marked as preferred_identifier
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# File 'lib/activefacts/generators/transform/datavault.rb', line 165 def create_two_role_identifier(r1, r2) pc = @constellation.PresenceConstraint( :concept => :new, :vocabulary => @vocabulary, :name => r1.object_type.name+' '+r1.object_type.name+'PK', :role_sequence => [:new], :is_mandatory => true, :min_frequency => 1, :max_frequency => 1, :is_preferred_identifier => true ) @constellation.RoleRef(:role_sequence => pc.role_sequence, :ordinal => 0, :role => r1) @constellation.RoleRef(:role_sequence => pc.role_sequence, :ordinal => 1, :role => r2) end |
#detect_required_surrogates ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 71 def detect_required_surrogates trace :datavault, "Detecting required surrogates" do @required_surrogates = (@hub_tables+@link_tables).select do |table| table.dv_needs_surrogate end end end |
#generate(out = $stdout) ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 247 def generate(out = $stdout) @out = out # Strategy: # Determine list of ER tables # Partition tables into reference tables (annotated), link tables (two+ FKs in PK), and hub tables # For each hub and link table # Apply a surrogate key if needed (all links, hubs lacking a simple surrogate) # Detect references (fact types) leading to all attributes (non-identifying columns) # Group attribute facts into satellites (use the satellite annotation if present) # For each satellite # Create a new entity type with a (hub-key, record-date key) # Make new one->many fact type between hub and satellite # Modify all attribute facts in this group to attach to the satellite # Compute a gresh relational mapping # Exclude reference tables and disable enforcement to them classify_tables detect_required_surrogates @sat_tables = [] trace :datavault, "Creating satellites" do (@hub_tables+@link_tables).each do |table| satellites = classify_satellite_references table next unless satellites trace :datavault, "Creating #{satellites.size} satellites for #{table.name}" do satellites.each do |satellite_name, references| @sat_tables << create_satellite(table, satellite_name, references) end end end end trace :datavault, "#{@sat_tables.size} satellite tables created" inject_required_surrogates trace :datavault, "Adding standard fields to hubs and links" do (@hub_tables+@link_tables).each do |table| date_time = assert_date_time date_time_role = create_one_to_many(date_time, table, 'is of', 'was loaded at', 'load') record_source = assert_record_source record_source_role = create_one_to_many(record_source, table, 'is of', 'was loaded from') end end # Now, redo the E-R mapping using the revised schema: @vocabulary.decide_tables # Suffix Hub and Link tables with HUB and LINK @hub_tables.each { |h| h.name = "#{h.name} HUB"} @link_tables.each { |l| l.name = "#{l.name} LINK"} # Before departing, ensure we don't emit the reference tables! @reference_tables.each do |table| table.definitely_not_table @vocabulary.tables.delete(table) end end |
#inject_required_surrogates ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 80 def inject_required_surrogates trace :datavault, "Injecting any required surrogates" do trace :datavault, "Need to inject surrogates into #{@required_surrogates.map(&:name)*', '}" @required_surrogates.each do |table| table.dv_inject_surrogate end end end |
#lift_role_to_link(ref, table_role) ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 180 def lift_role_to_link(ref, table_role) trace :datavault, "Broaden #{ref} into a new link" uc = table_role.uniqueness_constraint one_to_one_constraint = ref.fact_type.internal_presence_constraints.detect{|pc| pc != uc } # Any query Step or Reading on this fact type should be unaffected # Make a new RoleRef for the uniqueness constraint so it spans uc.constellation.RoleRef(uc.role_sequence, 1, :role => ref.to_role) one_to_one_constraint.retract if one_to_one_constraint # Add the objectifying entity type: et = uc.constellation.EntityType( uc.vocabulary, "#{ref.from.name} #{ref.to_names*' '}", :fact_type => ref.fact_type, :concept => :new ) # REVISIT: Objectifying requires creation of LinkFactTypes. @link_tables << et end |
#trace_table_classifications ⇒ Object
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# File 'lib/activefacts/generators/transform/datavault.rb', line 57 def trace_table_classifications # Trace the decisions about table types: if trace :datavault [@reference_tables, @hub_tables, @link_tables].zip(['Reference', 'Hub', 'Link']).each do |tables, kind| trace :datavault, kind+' tables:' do tables.each do |table| = table.identifier_columns.map{|c| c.references.first}.uniq trace :datavault, "#{table.name}(#{.map{|r| (t = r.to) && t.name || 'self'}*', '})" end end end end end |