class ActiveRecord::ConnectionAdapters::Table

t.index([:branch_id, :party_id], :unique => true, :name => 'by_branch_party')
====== Creating a named index
t.index([:branch_id, :party_id], :unique => true)
====== Creating a unique index
t.index(:name)
====== Creating a simple index
===== Examples

an Array of Symbols. See SchemaStatements#add_index
Adds a new index to the table. +column_name+ can be a single Symbol, or

def index(column_name, options = {})
  @base.add_index(@table_name, column_name, options)
end