M.Schwern 氏の Perl Refactoring 講座実例つき。
perl.com: A Refactoring Example [Oct. 09, 2003]
About a year ago, a person asked the Fun With Perl mailing list about some code they had written to do database queries. It's important to note that this person was posting from an .it address; why will become apparent later. The code was reading records in from a text file and then doing a series of queries based on that information. They wanted to make it faster.