This is an extract from
http://www.codeforpeople.com/lib/ruby/arrayfields/arrayfields-3.5.0/README
that i am trying to understand.



relation = pgconn.query sql
    relation.size                #=> 65536

    # yikes! do we really want to re-construct a hash for for each
tuple when
    # we already have Arrays?

    fields = %w(ssn name position)
    table.each{|tuple| tuple.fields = fields}

    tuples[34578]['ssn']         #=> 574865032

What does this term mean %w.......