Im running an older version of mysql, 4.0.16-nt and i get some real bad performance during a left join with is null
select distinct ih.* from InvoiceHeader ih
left join invoiceresponsibleuser iru on
WHERE (status = 201 AND iru.useruuid IS NULL)
order by ih.invoiceNumber ASC
Is there an easy way to up the performance of this query? As mysql 4.0.16 doesnt handle subqueries im not sure what i can do.