Ways to speed up this query

Question

i was wondering if anyone has any ideas on how to speed this query up
SELECT NAME, trunc (opr_date + opr_hour/24-numtodsinterval(1,'second'), 'DDD') AS opr_date, PRICE,
Case OPR_HOUR When 0 THEN 24  ELSE OPR_HOUR END AS OPR_HOUR
FROM ze_data.pjm_edf_lmp_hourly_int
WHERE trunc (opr_date + opr_hour/24-numtodsinterval(1,'second'), 'DDD') between to_date ('2010/07/26', 'yyyy/mm/dd') and to_date ('2010/07/28', 'yyyy/mm/dd') and NAME in ('MISO')
ORDER BY OPR_DATE desc, opr_hour descThe data is stored in the database with hours 0 to 23 this code take hour 0 and switches it to hour 24 of the the day before. I was wondering if there was a way to speed up the query as it takes 8 seconds to run
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0

Answer 1

Since you're comparing OPR_DATE to a date range, is there any need to add the time to OPR_DATE?
Would this work better? An index on OPR_DATE might help, but wouldn't an index on NAME be even better?
I don't know, just a guess. You haven't posted anything we can use.
SELECT NAME
      ,trunc (opr_date + opr_hour/24-numtodsinterval(1,'second'), 'DDD') AS opr_date
      ,PRICE
      ,Case OPR_HOUR When 0 THEN 24  ELSE OPR_HOUR END AS OPR_HOUR
FROM   ze_data.pjm_edf_lmp_hourly_int
WHERE  opr_date >= to_date ('2010/07/26', 'yyyy/mm/dd')
and    opr_date <= to_date ('2010/07/28', 'yyyy/mm/dd')
and    NAME in ('MISO')
ORDER  BY OPR_DATE desc, opr_hour desc;