How to use Percent_Rank to knock out the bottom and top 10% of query?

Question

Hi,
I'm trying to use Percent_Rank to knock off the bottom and top 10% of a query result, and then take an average of what's left.
The query is of the form:
SELECT 'Average Resolution Time Days' Service_Time_Type,
ROUND(NVL(AVG(NVL(hds.hds_working_duration(jr.date_lodged, jas.job_close_date),0)),0),2) Time_Days
FROM hds.hds_job_request jr, hds.hds_job_assignment jas
WHERE jr.job_id = jas.job_id
and jas.job_close_date is not null
AND jas.job_close_date >= '01-JAN-2006'
AND jas.job_close_date < '01-NOV-2006'
I would like to add a: WHERE PERCENT_RANK ?????? BETWEEN 0.10 and 0.90, but I can't work out how to use it, can someone help?
Thanks
Adam
Message was edited by:
Adam Sawyer

Answer 1

I worked it out:
This is the query I ended up with:
SELECT 'Average Resolution Time Days' Service_Time_Type,
ROUND(AVG(duration),2) Time_Days
FROM
SELECT hds.hds_working_duration(jr.date_lodged, jas.job_close_date) duration,
round(percent_rank() over (order by hds.hds_working_duration(jr.date_lodged, jas.job_close_date)),2) pr
FROM hds.hds_job_request jr, hds.hds_job_assignment jas
WHERE jr.job_id = jas.job_id
AND jas.job_close_date IS NOT NULL
AND jas.job_close_date >= '01-JAN-2006'
AND jas.job_close_date < '01-NOV-2006'
WHERE pr BETWEEN 0.1 AND 0.9
ORDER BY 1
Thanks for all your help
Cheers
Adam