What are some alternatives to a database?

I want to store data and read/modify it on my Web server using Perl. I don't need something big and scary like SQL. Are there any modules or even just standard syntax for plaintext files to do this?

>>11

7/10 I'm responding seriously:

Implying your shitty homebrewed linear search on a flat file will outperform a database system written by experts and optimised over years.

Especially something like SQLite.