comparison of mongo's grep vs. pcregrep on 400+MB of log files

Gemfile

source :rubygems 
gem "bson_ext"
gem "mongo"
gem "logging"

grep.rb

require "rubygems"
require "bundler"
Bundler.require(:default)

db = Mongo::Connection.new("localhost").db("f3h")
logs = db.collection("logs")

cursor = logs.find({"line" => { "$regex" => Regexp.compile(ARGV.first, true)}}, :limit => 0)
puts cursor.count

load.rb

require "rubygems"
require "bundler"
Bundler.require(:default)

require "iconv"

logger = Logging.logger(STDOUT)
logger.level = :info

db = Mongo::Connection.new("localhost").db("f3h")
logs = db.collection("logs")

start = Time.now

logger.info "starting load..."

iconv = Iconv.new "UTF8", "ISO-8859-1"

Dir.glob("**/*.log").sort.each do |logfile|
  logger.info "loading #{logfile}"
  File.open(logfile, "r:ISO-8859-1") do |input|
    input.each_line do |line|
      line = iconv.conv(line)
      # timestamp = /^\[([^\]]+)\]/.match(line)[1]
      # time = Time.strptime timestamp, "%m/%d/%y %H:%M:%S"
      logs.insert :line => line
    end
  end
end

logger.info "done loading, took #{Time.now - start} seconds"