The first step is to paste the following code into your functions.php file:

function pdflink($attr, $content) {
	return '<a class="pdf" href="http://docs.google.com/viewer?url=
        ' . $attr['href'] . '">'.$content.'</a>';
        }
add_shortcode('pdf', 'pdflink');

Once you saved the file, you’ll be able to use the…

Paste the following code into a text file, and save it as blockbadqueries.php. Once done, upload it to your wp-content/plugins directory and activate it like any other plugins. That’s all!

<?php
/*
Plugin Name: Block Bad Queries
Plugin URI: http://perishablepress.com/press/2009/12/22/

…

Just run the following query on your WordPress database, and all revisions (As well as meta associated with it) will be deleted from your database.
Of course, do not forget to make a backup of your database before running…