Added back in basic benchmark support. To run:

ruby benchmark/benchmark.rb --adapter mysql --num 1000
  ruby benchmark/benchmark.rb --adapter mysql --num 1000 --to-csv /tmp/results.csv
  ruby benchmark/benchmark.rb --adapter mysql --num 1000 --to-html /tmp/results.html

benchmarks/lib/base.rb

@@ -0,0 +1,137 @@
+class BenchmarkBase
+
+  attr_reader :results
+
+  # The main benchmark method dispatcher. This dispatches the benchmarks
+  # to actual benchmark_xxxx methods.
+  # 
+  # == PARAMETERS
+  #  * table_types - an array of table types to benchmark
+  #  * num - the number of record insertions to test
+  def benchmark( table_types, num )
+    array_of_cols_and_vals = build_array_of_cols_and_vals( num )
+    table_types.each do |table_type|
+      self.send( "benchmark_#{table_type}", array_of_cols_and_vals )
+    end
+  end
+
+  # Returns an OpenStruct which contains two attritues, +description+ and +tms+ after performing an
+  # actual benchmark.
+  #
+  # == PARAMETERS
+  #  * description - the description of the block that is getting benchmarked
+  #  * blk - the block of code to benchmark
+  #
+  # == RETURNS
+  # An OpenStruct object with the following attributes:
+  #   * description - the description of the benchmark ran
+  #   * tms - a Benchmark::Tms containing the results of the benchmark
+  def bm( description, &blk )
+    tms  = nil
+    puts "Benchmarking #{description}"
+    
+    Benchmark.bm { |x| tms = x.report { blk.call } }
+    delete_all
+    failed = false
+
+    OpenStruct.new :description=>description, :tms=>tms, :failed=>failed
+  end
+  
+  # Given a model class (ie: Topic), and an array of columns and value sets
+  # this will perform all of the benchmarks necessary for this library.
+  # 
+  # == PARAMETERS
+  #  * model_clazz - the model class to benchmark (ie: Topic)
+  #  * array_of_cols_and_vals - an array of column identifiers and value sets
+  #
+  # == RETURNS
+  #  returns true
+  def bm_model( model_clazz, array_of_cols_and_vals )
+    puts
+    puts "------ Benchmarking #{model_clazz.name} -------"
+
+    cols,vals = array_of_cols_and_vals
+    num_inserts = vals.size
+
+    # add a new result group for this particular benchmark
+    group = []
+    @results << group
+
+    description = "#{model_clazz.name}.create (#{num_inserts} records)"
+    group << bm( description ) { 
+      vals.each do |values|
+        model_clazz.create create_hash_for_cols_and_vals( cols, values )
+      end  }
+
+    description = "#{model_clazz.name}.import(column, values) for #{num_inserts} records with validations"
+    group << bm( description ) { model_clazz.import cols, vals, :validate=>true }
+
+    description = "#{model_clazz.name}.import(columns, values) for #{num_inserts} records without validations"
+    group << bm( description ) { model_clazz.import cols, vals, :validate=>false }
+
+    models = []
+    array_of_attrs = []
+    
+    vals.each do |arr|
+      array_of_attrs << (attrs={})
+      arr.each_with_index { |value, i| attrs[cols[i]] = value }
+    end
+    array_of_attrs.each{ |attrs| models << model_clazz.new(attrs) }
+
+    description = "#{model_clazz.name}.import(models) for #{num_inserts} records with validations"
+    group << bm( description ) { model_clazz.import models, :validate=>true }
+
+    description = "#{model_clazz.name}.import(models) for #{num_inserts} records without validations"
+    group << bm( description ) { model_clazz.import models, :validate=>false }
+
+    true
+  end
+
+  # Returns a two element array composing of an array of columns and an array of
+  # value sets given the passed +num+.
+  #
+  # === What is a value set?
+  # A value set is an array of arrays. Each child array represents an array of value sets
+  # for a given row of data. 
+  #
+  # For example, say we wanted to represent an insertion of two records:
+  #   column_names = [ 'id', 'name', 'description' ]
+  #   record1 = [ 1, 'John Doe', 'A plumber' ]
+  #   record2 = [ 2, 'John Smith', 'A painter' ]
+  #   value_set [ record1, record2 ]
+  #
+  # == PARAMETER
+  #  * num - the number of records to create
+  def build_array_of_cols_and_vals( num )
+    cols = [ :my_name, :description ]
+    value_sets = []
+    num.times { |i| value_sets << [ "My Name #{i}", "My Description #{i}" ] }
+    [ cols, value_sets ]
+  end
+
+  # Returns a hash of column identifier to value mappings giving the passed in
+  # value array. 
+  #
+  # Example:
+  #   cols = [ 'id', 'name', 'description' ]
+  #   values = [ 1, 'John Doe', 'A plumber' ]
+  #   hsh = create_hash_for_cols_and_vals( cols, values )   
+  #   # hsh => { 'id'=>1, 'name'=>'John Doe', 'description'=>'A plumber' }
+  def create_hash_for_cols_and_vals( cols, vals )
+    h = {}
+    cols.zip( vals ){ |col,val| h[col] = val }
+    h
+  end
+
+  # Deletes all records from all ActiveRecord subclasses
+  def delete_all
+    ActiveRecord::Base.send( :subclasses ).each do |subclass|
+      subclass.delete_all if subclass.respond_to? :delete_all
+    end
+  end
+
+  def initialize   # :nodoc:
+    @results = []
+  end
+	
+end