Grouping error in Oracle's analytic function PERCENTILE_CONT()

Question

Hi,
I have a question regarding the usage of Oracle's analytic function PERCENTILE_CONT(). The underlying time data in the table is of hourly granularity and I want to fetch average, peak values for the day along with 80th percentile for that day. For the sake of clarification I am only posting relevant portion of the query.
Any idea how to rewrite the query and achieve the same objective?
SELECT   TRUNC (sdd.ts) AS ts,
         max(sdd.maxvalue) AS max_value, avg(sdd.avgvalue) AS avg_value,
         PERCENTILE_CONT(0.80) WITHIN GROUP (ORDER BY  sdd.avgvalue ASC) OVER (PARTITION BY pm.sysid,trunc(sdd.ts)) as Percentile_Cont_AVG
FROM     XYZ
WHERE
          XYZ
GROUP BY  TRUNC (sdd.ts)  
ORDER BY  TRUNC (sdd.ts)
Oracle Error:
ERROR at line 5:
ORA-00979: not a GROUP BY expression

Answer 1

You probably mixed up the aggregate and analytical versin of PERCENTILE_CONT.
The below should work, but i dont know if it produces the desireed results.
SELECT   TRUNC (sdd.ts) AS ts,
         max(sdd.maxvalue) AS max_value, avg(sdd.avgvalue) AS avg_value,
         PERCENTILE_CONT(0.80) WITHIN GROUP (ORDER BY  sdd.avgvalue ASC)  as Percentile_Cont_AVG
FROM     XYZ
sorry, what is this where clause for??
WHERE
          XYZ
GROUP BY  TRUNC (sdd.ts)  
ORDER BY  TRUNC (sdd.ts) Edited by: chris227 on 26.03.2013 05:45