selecting from a view is taking longer than 30+ minutes - tsql

Question

I am working on making this view fast enough to fetch the result set in reasonable time which is at the moment taking more than 30+ minutes, going parallel and causing all sorts of pain with increased cpu time. I have identified the problem query but I can't figure out a way to cut the execution time by either re-writing the query or adding appropriate index if needed. We already have clustered index on client_id and non clustered index on the hash_key column in both the tables. Also these respective join tables have close to around 238 million records from work_orders and a total of 287011570 records from s_inspections table.
select
wo.client_id,
wo.work_orders_hash_key,
wo.work_order_number,
wo.work_order_id,
si.inspection_id,
si.inspection_name,
si.inspection_detail,
si.master_inspection_id,
si.master_inspection_detail,
si.status_id,
si.exception,
si.inspection_order,
si.comment,
si.[procedure_id],
si.[flag_id],
si.[asset_id],
si.[asset_name],
si.[inspection_status],
si.[is_removed],
si.[response],
row_number() over(partition by si.work_orders_hash_key, si.inspection_id order by si.dss_version desc) rnk
from
datavault.dbo.h_work_orders wo with (readuncommitted)
join datavault.dbo.s_inspections si with (readuncommitted) on wo.client_id = si.client_id and wo.work_orders_hash_key = si.work_orders_hash_key
where
wo.client_id in (7700876368663, 8800387996408)
Below is the estimated execution plan as it was taking quite sometime so I couldn't provide the actual execution plan.
https://www.brentozar.com/pastetheplan/?id=ryLzvNwUN
Any help would be greatly appreciated.

Answer 1

Your compute scalar is 59% of your query cost.
I would guess it's this line:
row_number() over(partition by si.work_orders_hash_key, si.inspection_id order by si.dss_version desc) rnk
It's estimating 159014000000000 rows!
Whack this line (lot of work to return a row number) and run it again.

Answer 2

maybe this will work to keep you in business since the row_number() was the issue. try:
;with x as (
select
wo.client_id,
wo.work_orders_hash_key,
wo.work_order_number,
wo.work_order_id,
si.inspection_id,
si.inspection_name,
si.inspection_detail,
si.master_inspection_id,
si.master_inspection_detail,
si.status_id,
si.exception,
si.inspection_order,
si.comment,
si.[procedure_id],
si.[flag_id],
si.[asset_id],
si.[asset_name],
si.[inspection_status],
si.[is_removed],
si.[response],
si.dss_version
from
datavault.dbo.h_work_orders wo with (readuncommitted)
join datavault.dbo.s_inspections si with (readuncommitted) on wo.client_id = si.client_id and wo.work_orders_hash_key = si.work_orders_hash_key
where
wo.client_id in (7700876368663, 8800387996408)
)
select
x.client_id,
x.work_orders_hash_key,
x.work_order_number,
x.work_order_id,
x.inspection_id,
x.inspection_name,
x.inspection_detail,
x.master_inspection_id,
x.master_inspection_detail,
x.status_id,
x.exception,
x.inspection_order,
x.comment,
x.[procedure_id],
x.[flag_id],
x.[asset_id],
x.[asset_name],
x.[inspection_status],
x.[is_removed],
x.[response],
row_number() over(partition by x.work_orders_hash_key, x.inspection_id order by x.dss_version desc) rnk
from x;