Module: UmbrellioUtils::Database

Extended by:
Database
Included in:
Database
Defined in:
lib/umbrellio_utils/database.rb

Constant Summary collapse

HandledConstaintError = 
Class.new(StandardError)
InvalidPkError = 
Class.new(StandardError)

Instance Method Summary collapse

Instance Method Details

#create_temp_table(dataset, primary_key: nil, temp_table_name: nil) ⇒ Object

rubocop:enable Metrics/ParameterLists



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# File 'lib/umbrellio_utils/database.rb', line 82

def create_temp_table(dataset, primary_key: nil, temp_table_name: nil)
  time = Time.current
  model = dataset.model

  temp_table_name ||= :"temp_#{model.table_name}_#{time.to_i}_#{time.nsec}"
  return temp_table_name if DB.table_exists?(temp_table_name)

  primary_key = primary_key_from(dataset, primary_key:)

  DB.create_table(temp_table_name, unlogged: true) do
    primary_key.each do |field|
      type = model.db_schema[field][:db_type]
      column(field, type)
    end

    primary_key(primary_key)
  end

  insert_ds = dataset.select(*qualified_pk(model.table_name, primary_key))
  DB[temp_table_name].disable_insert_returning.insert(insert_ds)

  temp_table_name
end

#each_record(dataset, primary_key: nil, **options, &block) ⇒ Object 



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# File 'lib/umbrellio_utils/database.rb', line 26

def each_record(dataset, primary_key: nil, **options, &block)
  primary_key = primary_key_from(dataset, primary_key:)
  eager_tables = Array(options.delete(:eager_load))

  with_temp_table(dataset, primary_key:, **options) do |ids|
    rows = ids.map { |id| row(id.is_a?(Hash) ? id.values : [id]) }
    records = dataset.model
           .eager(eager_tables)
           .where(row(primary_key) => rows)
           .reverse(row(primary_key)).all
    records.each(&block)
  end
end

#get_violated_constraint_name(exception) ⇒ Object 



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# File 'lib/umbrellio_utils/database.rb', line 21

def get_violated_constraint_name(exception)
  error = exception.wrapped_exception
  error.result.error_field(PG::Result::PG_DIAG_CONSTRAINT_NAME)
end

#handle_constraint_error(constraint_name) ⇒ Object 



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# File 'lib/umbrellio_utils/database.rb', line 11

def handle_constraint_error(constraint_name, &)
  DB.transaction(savepoint: true, &)
rescue Sequel::UniqueConstraintViolation => e
  if constraint_name.to_s == get_violated_constraint_name(e)
    raise HandledConstaintError
  else
    raise e
  end
end

#with_temp_table(dataset, page_size: 1_000, sleep: nil, primary_key: nil, temp_table_name: nil, transaction: true) ⇒ Object

Iterates over a dataset and yields batches of primary keys. First, a temporary table is created and populated with dataset primary keys. After that, a batch of rows is deleted from the temp table on each iteration and gets yielded to the caller. rubocop:disable Metrics/ParameterLists

Parameters:

  • [Integer] (Hash) —

    a customizable set of options

  • [Array] (Hash) —

    a customizable set of options

  • [Symbol, (Hash) —

    a customizable set of options



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# File 'lib/umbrellio_utils/database.rb', line 50

def with_temp_table(
  dataset,
  page_size: 1_000,
  sleep: nil,
  primary_key: nil,
  temp_table_name: nil,
  transaction: true
)
  primary_key = primary_key_from(dataset, primary_key:)
  sleep_interval = sleep_interval_from(sleep)

  temp_table_name = create_temp_table(
    dataset, primary_key:, temp_table_name: temp_table_name&.to_sym
  )

  pk_set = []

  loop do
    conditional_transaction(transaction) do
      pk_set = pop_next_pk_batch(temp_table_name, primary_key, page_size)
      yield(pk_set) if pk_set.any?
    end

    break if pk_set.empty?

    Kernel.sleep(sleep_interval) if sleep_interval.positive?
  end

  DB.drop_table(temp_table_name)
end