Ach ja, hier wollte ich ja auch mal meinen Senf zu geben, hoffentlich schmeckts - gibt nachher auch Bratwürstchen dazu

Folgenden Code einfach mal in einem Query-Browser (mysql,phpMyAdmin...) ausführen.
Code:
EXPLAIN
SELECT
        paidmails.*,
        gebucht.k_code AS mail_gebucht,
        black.k_code AS mail_black,
        reload.k_reload AS mail_reload_reload
    FROM " . $prefix . _DB_TABLE_PWC_PM . " AS paidmails
        LEFT JOIN " . $prefix . _DB_TABLE_PWC_PM_GEBUCHT . " AS gebucht
    ON (paidmails.k_code = gebucht.k_code)
        LEFT JOIN " . $prefix . _DB_TABLE_PWC_PM_BLACKLISTE . " AS black
    ON (paidmails.k_code = black.k_code)
        LEFT JOIN " . $prefix . _DB_TABLE_PWC_PM_RELOAD . " AS reload
    ON (paidmails.k_code = reload.k_code)
        WHERE paidmails.k_sponsor = 12
        AND paidmails.k_art = $k_art
        ORDER BY paidmails.k_ver DESC
Mehr dazu