gistfile1.rb

require "rubygems"
require "pg"
require "rbench"

query = "SELECT * FROM people WHERE id = $1 LIMIT 1"
conn = PGconn.open(:dbname => "random_test")
stmt = conn.prepare "orm_load", query

RBench.run(100000) do

  column :times
  column :time

  report 'Prepared statements' do
    time {
      id = rand 1_000_000
      result = conn.exec_prepared("orm_load", [id])
      # p result.field_values("name")[0]
    }
  end

  report 'Direct SQL' do
    time {
      id = rand 1_000_000
      result = conn.exec(query, [id])
      # p result.field_values("name")[0]
    }
  end
end

# My results, using pg 0.9.0, Postgres 8.4.2, and Ruby 1.9.2-head,
# on a table with 2 fields and one million rows:
#
#                                     |    TIME |
# -----------------------------------------------
# Prepared statements         x100000 |  11.099 |
# Direct SQL                  x100000 |  17.639 |