Set,

i took note of your comments and changed the query so that the restriction
was performed in the join. As the original query has 2 other joins in it and
a large 'where' clause i was about to migrate the other sections of the
where clause to the relevent join conditions and then realised that you said
'left join'. as the other 2 joins are 'join' rather than 'left join' would
it be safe to leave the restrictions in the 'where' clause?

Kind regards,
Pete