Wordpress Tips & Tricks
SQL: Delete all images from image library
DELETE FROM etkwp_postmeta WHERE post_id IN (SELECT id FROM etkwp_posts WHERE post_type = 'attachment');
DELETE FROM etkwp_posts WHERE post_type = 'attachment'
Attach / unattach images to posts
If you want images to be auto-removed on post deletion, use plugin Autoremove Attachments.
wp-config.php
WordPress constants overview - WP Engineer
A Guided Tour of WordPress’s wp-config.php File 10 wp-config Tweaks To Improve Your WordPress Site New wp-config Tweaks You Probably Don’t Know - Tuts+ Code Article
define( ‘CORE_UPGRADE_SKIP_NEW_BUNDLED’, true );
Conquering the wp-config.php File - 11 Good Practices
define(‘DISALLOW_FILE_EDIT’,true);
Warn that deprecated WPLANG constant will be ignored
10 Things you did not know about WordPress - Remkus de Vries
Override Wordpress Site URL With wp-config.php
Exhaustive The Developer’s Advanced Guide to the wp-config File