gistfile1.builder

# estimate the duration of an ALTER TABLE statement in mysql
# this code estimates the worst case, as most of the time, an ALTER will result in a table that is smaller than the original

percentage = 0
interval = 10
while(true) do
  sleep(interval)
  new_percentage = (File.size('#sql-5316_1a.ibd')*1.0 / File.size('moves.ibd')*1.0)
  change = new_percentage - percentage
  intervals = 1.0/change
  duration = intervals*interval
  eta = Time.now + duration
  percentage = new_percentage
  puts "percent done: #{percentage}"
  puts "eta: #{eta}"
  puts "estimated duration: #{duration/60} minutes (#{duration/60/60} hours)"
end