Interesting SQL...

Anyone else experience this?

A developer just finished complaining about the performance of one of our databases. Well, he sent me the query and I couldn't understand why it was such a dog. Anyways I rewrote it. The execution plan is totally different between the two. I had no idea specifying the join made such a difference. First sql executed in 7 minutes that 2nd took 1 second.

SELECT
dbo.contract_co.producer_num_id, contract_co_status
FROM
dbo.contract_co,
dbo.v_contract_co_status
WHERE ( dbo.v_contract_co_status.contract_co_id = dbo.contract_co.contract_co_id )
AND contract_co_status = 'Pending'
OR ( contract_co_status = 'Active' and effective_date > '1/1/2004' )

SELECT
dbo.contract_co.producer_num_id, contract_co_status
FROM dbo.contract_co
INNER JOIN dbo.v_contract_co_status
ON dbo.contract_co.contract_co_id = dbo.v_contract_co_status.contract_co_id
WHERE contract_co_status = 'Pending'
OR ( contract_co_status = 'Active' and effective_date > '1/1/2004' )