DELETE FROM ps_connections WHERE date_add < now() - interval 30 day;
DELETE FROM ps_connections_source WHERE date_add < now() - interval 30 day;
TRUNCATE TABLE ps_connections_page;
DELETE FROM ps_pagenotfound WHERE date_add < now() - interval 90 day;
DELETE FROM ps_statssearch WHERE date_add < now() - interval 90 day;
DELETE FROM ps_log WHERE date_add < now() - interval 90 day;
DELETE FROM ps_mail WHERE date_add < now() - interval 90 day;

DELETE ps_cart_product FROM ps_cart_product JOIN ps_cart ON ps_cart.id_cart = ps_cart_product.id_cart WHERE ps_cart.date_add < now() - interval 90 day;
DELETE FROM ps_cart WHERE ps_cart.date_add < now() - interval 90 day;

DELETE g FROM ps_guest g LEFT JOIN ps_customer c ON (g.id_customer = c.id_customer) WHERE c.id_customer IS NULL;

SQL para eliminar registros (excepto de los últimos 90 días).