Module: Partitionable::ActsAsPartitionable::ClassMethods

Defined in:
lib/partitionable/acts_as_partitionable.rb

Instance Method Summary collapse

Instance Method Details

#acts_as_partitionable(options = {}) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 10

def acts_as_partitionable(options = {})
  cattr_accessor :index_fields
  cattr_accessor :logdate_attr
  self.index_fields = options[:index_fields]
  self.logdate_attr = options[:logdate_attr]

  def partition_name(month, year)
    formatted_month = sprintf('%02d', month.to_i)
    "#{self.table_name}_y#{year}m#{formatted_month}"
  end

  def create_partition(month, year)
    ActiveRecord::Base.connection.execute create_table_statement(month, year)
  end

  def create_table_statement(month, year)
    table = partition_name(month, year)
    index_name = "#{table}_#{index_fields.join('_')}"
    first_day_of_month = Date.civil(year, month, 1)
    first_day_next_month = (first_day_of_month + 1.month)
    "    CREATE TABLE \#{table} (\n        CHECK ( \#{self.logdate_attr} >= DATE '\#{first_day_of_month.to_s}' AND \#{self.logdate_attr} < DATE '\#{first_day_next_month.to_s}' )\n    ) INHERITS (\#{self.table_name});\n    CREATE INDEX \#{index_name} ON \#{table} (\#{index_fields.join(',')});\n    SQL\n  end\n\n  def drop_partition(month, year)\n    name = partition_name(month, year)\n    index_name = \"\#{name}_\#{index_fields.join('_')}\"\n    function_name = \"\#{name}_insert_trigger_function()\"\n    trigger_name = \"\#{name}_trigger\"\n    ActiveRecord::Base.connection.execute(\n      <<-SQL\n    DROP TABLE IF EXISTS \#{name};\n    DROP INDEX IF EXISTS \#{index_name};\n    DROP FUNCTION IF EXISTS \#{function_name} CASCADE;\n    DROP TRIGGER IF EXISTS \#{trigger_name} ON \#{self.table_name} CASCADE;\n      SQL\n    )\n  end\n\n  def trigger_statement months_and_years\n    trigger_body = get_trigger_body(months_and_years)\n    statement = \"\"\n    statement += <<-SQL\n    CREATE OR REPLACE FUNCTION \#{self.table_name}_insert_trigger()\n    RETURNS TRIGGER AS $$\n    SQL\n\n    statement += trigger_body\n    statement += <<-SQL\n    $$\n    LANGUAGE plpgsql;\n\n    DROP TRIGGER IF EXISTS insert_\#{self.table_name}_trigger ON \#{self.table_name};\n    CREATE TRIGGER insert_\#{self.table_name}_trigger\n        BEFORE INSERT ON \#{self.table_name}\n        FOR EACH ROW EXECUTE PROCEDURE \#{self.table_name}_insert_trigger();\n    SQL\n    statement\n  end\n\n  def get_trigger_body months_and_years\n\n    statement = \"\"\n    statement += <<-eos\n    BEGIN\n    eos\n\n    months_and_years.each_with_index do |data, index|\n\n      first_day_of_month = Date.civil(data[1].to_i, data[0].to_i, 1)\n      first_day_next_month = (first_day_of_month + 1.month)\n      if index == 0\n        statement += <<-eos\n        IF ( NEW.\#{self.logdate_attr} >= DATE '\#{first_day_of_month}' AND\n             NEW.\#{self.logdate_attr} < DATE '\#{first_day_next_month}' ) THEN\n            INSERT INTO \#{partition_name(data[0], data[1])} VALUES (NEW.*);\n        eos\n      else\n        statement += <<-eos\n        ELSIF ( NEW.\#{self.logdate_attr} >= DATE '\#{first_day_of_month}' AND\n             NEW.\#{self.logdate_attr} < DATE '\#{first_day_next_month}' ) THEN\n            INSERT INTO \#{partition_name(data[0], data[1])} VALUES (NEW.*);\n        eos\n      end\n    end\n    statement += <<-eos\n        END IF;\n        RETURN NULL;\n    END;\n    eos\n  end\n\n  def partition_exists?(month, year)\n    ActiveRecord::Base.connection.data_source_exists? partition_name(month, year)\n  end\n\n  def update_trigger\n    ActiveRecord::Base.connection.execute updated_trigger_statement\n  end\n\n  def updated_trigger_statement\n    tables = ActiveRecord::Base.connection.tables.select{|t| t =~ /\#{self.table_name}_y[0-9]{4}m[0-9]{2}/}\n    months_and_years = tables.map {|t| [t.match(/m\\K[0-9]{2}/)[0], t.match(/y\\K[0-9]{4}/)[0]]}\n    trigger_statement months_and_years.sort_by{|month, year| [year.to_i, month.to_i]}\n  end\n\n  include Partitionable::ActsAsPartitionable::LocalInstanceMethods\nend\n"

#create_partition(month, year) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 21

def create_partition(month, year)
  ActiveRecord::Base.connection.execute create_table_statement(month, year)
end

#create_table_statement(month, year) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 25

def create_table_statement(month, year)
  table = partition_name(month, year)
  index_name = "#{table}_#{index_fields.join('_')}"
  first_day_of_month = Date.civil(year, month, 1)
  first_day_next_month = (first_day_of_month + 1.month)
  "  CREATE TABLE \#{table} (\n      CHECK ( \#{self.logdate_attr} >= DATE '\#{first_day_of_month.to_s}' AND \#{self.logdate_attr} < DATE '\#{first_day_next_month.to_s}' )\n  ) INHERITS (\#{self.table_name});\n  CREATE INDEX \#{index_name} ON \#{table} (\#{index_fields.join(',')});\n  SQL\nend\n"

#drop_partition(month, year) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 38

def drop_partition(month, year)
  name = partition_name(month, year)
  index_name = "#{name}_#{index_fields.join('_')}"
  function_name = "#{name}_insert_trigger_function()"
  trigger_name = "#{name}_trigger"
  ActiveRecord::Base.connection.execute(
    "  DROP TABLE IF EXISTS \#{name};\n  DROP INDEX IF EXISTS \#{index_name};\n  DROP FUNCTION IF EXISTS \#{function_name} CASCADE;\n  DROP TRIGGER IF EXISTS \#{trigger_name} ON \#{self.table_name} CASCADE;\n    SQL\n  )\nend\n"

#get_trigger_body(months_and_years) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 74

def get_trigger_body months_and_years

  statement = ""
  statement += "  BEGIN\n  eos\n\n  months_and_years.each_with_index do |data, index|\n\n    first_day_of_month = Date.civil(data[1].to_i, data[0].to_i, 1)\n    first_day_next_month = (first_day_of_month + 1.month)\n    if index == 0\n      statement += <<-eos\n      IF ( NEW.\#{self.logdate_attr} >= DATE '\#{first_day_of_month}' AND\n           NEW.\#{self.logdate_attr} < DATE '\#{first_day_next_month}' ) THEN\n          INSERT INTO \#{partition_name(data[0], data[1])} VALUES (NEW.*);\n      eos\n    else\n      statement += <<-eos\n      ELSIF ( NEW.\#{self.logdate_attr} >= DATE '\#{first_day_of_month}' AND\n           NEW.\#{self.logdate_attr} < DATE '\#{first_day_next_month}' ) THEN\n          INSERT INTO \#{partition_name(data[0], data[1])} VALUES (NEW.*);\n      eos\n    end\n  end\n  statement += <<-eos\n      END IF;\n      RETURN NULL;\n  END;\n  eos\nend\n"

#partition_exists?(month, year) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/partitionable/acts_as_partitionable.rb', line 106

def partition_exists?(month, year)
  ActiveRecord::Base.connection.data_source_exists? partition_name(month, year)
end

#partition_name(month, year) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 16

def partition_name(month, year)
  formatted_month = sprintf('%02d', month.to_i)
  "#{self.table_name}_y#{year}m#{formatted_month}"
end

#trigger_statement(months_and_years) ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 53

def trigger_statement months_and_years
  trigger_body = get_trigger_body(months_and_years)
  statement = ""
  statement += "  CREATE OR REPLACE FUNCTION \#{self.table_name}_insert_trigger()\n  RETURNS TRIGGER AS $$\n  SQL\n\n  statement += trigger_body\n  statement += <<-SQL\n  $$\n  LANGUAGE plpgsql;\n\n  DROP TRIGGER IF EXISTS insert_\#{self.table_name}_trigger ON \#{self.table_name};\n  CREATE TRIGGER insert_\#{self.table_name}_trigger\n      BEFORE INSERT ON \#{self.table_name}\n      FOR EACH ROW EXECUTE PROCEDURE \#{self.table_name}_insert_trigger();\n  SQL\n  statement\nend\n"

#update_trigger ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 110

def update_trigger
  ActiveRecord::Base.connection.execute updated_trigger_statement
end

#updated_trigger_statement ⇒ Object 



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# File 'lib/partitionable/acts_as_partitionable.rb', line 114

def updated_trigger_statement
  tables = ActiveRecord::Base.connection.tables.select{|t| t =~ /#{self.table_name}_y[0-9]{4}m[0-9]{2}/}
  months_and_years = tables.map {|t| [t.match(/m\K[0-9]{2}/)[0], t.match(/y\K[0-9]{4}/)[0]]}
  trigger_statement months_and_years.sort_by{|month, year| [year.to_i, month.to_i]}
end