Module: ActiveWarehouse::Aggregate::RolapCommon

Included in:
PipelinedRolapAggregate, RolapAggregate
Defined in:
lib/active_warehouse/aggregate/rolap_common.rb

Instance Method Summary collapse

Instance Method Details

#aggregate_fields ⇒ Object

Convenience accessor that delegates to cube class method aggregate_fields. Returns an array of AggregateField instances, which are the fact columns from the fact table.



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# File 'lib/active_warehouse/aggregate/rolap_common.rb', line 59

def aggregate_fields
  cube_class.aggregate_fields
end

#aggregated_fact_column_sql ⇒ Object

Get a String that contains the SQL fragment for selecting the summed fact columns. Each column is aliased and then appended with “_sum” before joining together with commas.



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# File 'lib/active_warehouse/aggregate/rolap_common.rb', line 50

def aggregated_fact_column_sql
  aggregate_fields.collect { |c| 
    "#{c.strategy_name}(#{c.from_table_name}.#{c.name}) AS #{c.label_for_table}"
  }.join(",")
end

#dimensions_to_columns ⇒ Object

Convert all of the dimensions that the cube may be pivotted on into an array of Field instances, one per column in the each dimension hierarchy.

This method will also filter out duplicates so that a dimension attribute will only appear once in the aggregate even if it is used in multiple hierarchies.

Only dimension attributes which are defined in a hierarchy in the dimension will be included in the aggregate, unless none are in which case every dimension field is used.



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# File 'lib/active_warehouse/aggregate/rolap_common.rb', line 14

def dimensions_to_columns
  columns = []

  cube_class.dimensions_hierarchies.each do |dimension_name,hierarchy_names|
    dimension_class = cube_class.fact_class.dimension_class(dimension_name)
    dimension_table_name = dimension_class.table_name

    if !dimension_table_name
      raise "Did not find #{dimension_name} as a :belongs_to relationship in #{fact_class}"
    end

    hierarchy_names.each do |hierarchy_name|
      levels = dimension_class.hierarchy_levels[hierarchy_name]

      if levels
        levels.each do |level|
          next if columns.find{|c| c.table_alias == dimension_name && c.name == level.to_s}
          columns << Field.new(dimension_class,
                               dimension_class.columns_hash[level.to_s],
                               :table_alias=>dimension_name)
        end
      else
        column = dimension_class.columns_hash[hierarchy_name]
        next if columns.find{|c| c.table_alias == dimension_name && c.name == hierarchy_name}
        columns << Field.new(dimension_class,
                             dimension_class.columns_hash[hierarchy_name],
                             :table_alias=>dimension_name)
      end
    end
  end
  columns
end

#flat_table_name ⇒ Object

The table name to use for the flat table



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# File 'lib/active_warehouse/aggregate/rolap_common.rb', line 78

def flat_table_name
  "#{cube_class.name.tableize.singularize}_flat"
end

#rollup_table_name ⇒ Object

The table name to use for the rollup



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# File 'lib/active_warehouse/aggregate/rolap_common.rb', line 83

def rollup_table_name
  "#{cube_class.name.tableize.singularize}_rollup"
end

#tables_and_joins ⇒ Object

The SQL fragment for tables and joins which is used during the population of the “flattened” cube



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# File 'lib/active_warehouse/aggregate/rolap_common.rb', line 65

def tables_and_joins
  sql = "#{fact_class.table_name}"
  cube_class.dimensions_hierarchies.each do |dimension_name, hierarchy_names|
    dimension_table_name = fact_class.dimension_class(dimension_name).table_name
    sql += "\nJOIN #{dimension_table_name} as #{dimension_name}"
    sql += "\n  ON #{fact_class.table_name}."
    sql += "#{fact_class.dimension_relationships[dimension_name].primary_key_name}"
    sql += " = #{dimension_name}.id"
  end
  sql
end