Module: ActiveRecord::Explain

Included in:
Base, Relation
Defined in:
lib/active_record/explain.rb

Instance Method Summary collapse

Instance Method Details

#collecting_queries_for_explain ⇒ Object

Executes the block with the collect flag enabled. Queries are collected asynchronously by the subscriber and returned.



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# File 'lib/active_record/explain.rb', line 8

def collecting_queries_for_explain # :nodoc:
  ExplainRegistry.collect = true
  yield
  ExplainRegistry.queries
ensure
  ExplainRegistry.reset
end

#exec_explain(queries) ⇒ Object

Makes the adapter execute EXPLAIN for the tuples of queries and bindings. Returns a formatted string ready to be logged.



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# File 'lib/active_record/explain.rb', line 18

def exec_explain(queries) # :nodoc:
  str = queries.map do |sql, bind|
    [].tap do |msg|
      msg << "EXPLAIN for: #{sql}"
      unless bind.empty?
        bind_msg = bind.map {|col, val| [col.name, val]}.inspect
        msg.last << " #{bind_msg}"
      end
      msg << connection.explain(sql, bind)
    end.join("\n")
  end.join("\n")

  # Overriding inspect to be more human readable, especially in the console.
  def str.inspect
    self
  end

  str
end