Class: Remi::Parser::Postgres

Inherits:
Remi::Parser show all
Defined in:
lib/remi/data_subjects/postgres.rb

Overview

Postgres parser Used to parse results from a postgres extractor (see Extractor::Postgres).

Instance Attribute Summary

Attributes inherited from Remi::Parser

#context, #field_symbolizer, #fields, #logger

Instance Method Summary collapse

Methods inherited from Remi::Parser

#initialize

Constructor Details

This class inherits a constructor from Remi::Parser

Instance Method Details

#parse(postgres_extract) ⇒ Remi::DataFrame

Returns The data converted into a dataframe.

Parameters:

Returns:



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# File 'lib/remi/data_subjects/postgres.rb', line 86

def parse(postgres_extract)
  # Performance for larger sets could be improved by using bulk query (via COPY)
  logger.info "Converting Postgres query to a dataframe"

  hash_array = {}
  postgres_extract.data.each do |row|
    row.each do |field, value|
      (hash_array[field_symbolizer.call(field)] ||= []) << value
    end
  end

  # After converting to DF, clear the PG results to save memory.
  postgres_extract.data.clear

  Remi::DataFrame.create(:daru, hash_array, order: hash_array.keys)
end