SQL & PL/SQL

Hello All,

We are having a performance issue with the below logic wherein MAX is being used in order to get the latest instance/record for a given input variable ( p_in_header_id).. the item_key is having the format as :
p_in_header_id - <number generated from a sequence>

This query to fetch even 1 record takes around 1 minutes 30 sec..could someone please help if there is a better way to form this logic & to improve performance in this case.

We want to get the latest record for the item_key ( this we are getting using MAX (begin_date)) for a given p_in_header_id value.

Query 1 :
SELECT item_key FROM wf_items WHERE item_type = 'xxxxzzzz'
AND SUBSTR (item_key, 1, INSTR (item_key, '-') - 1) =p_in_header_id
AND root_activity ='START_REQUESTS'
AND begin_date =
(SELECT MAX (begin_date) FROM wf_items WHERE item_type = 'xxxxzzzz'
AND root_activity ='START_REQUESTS'
AND SUBSTR (item_key, 1, INSTR (item_key, '-') - 1) =p_in_header_id);


Could someone please help us with this performance issue..we are really stuck because of this

regards