Sql statement takes long to execute even with index

Question

Hi
I have the following sql statement.
Its explain plan states its "TABLE ACCESS FULL".
But upon creation of index for table PWRKF2MV, using
IDX(pafidt,ppdept,prodno,ppname) and IDX2(pmfaci,prodno), it uses both indexes
but time taken to execute is still the same as when there is no indexes.
Why is that so? Appreciate any help. Thank you.
Pls take note that the PWRKF2MV is a materialized view and MITBALC0 is a synonym.
SQL statement: -
select a.ppdept dept, rtrim(b.mbsttx) prod, to_char(to_date(a.pafidt,'YYYYMMDD'),'Y')||to_char(to_date(a.pafidt,'YYYYMMDD'),'WW') as yrweek, sum(pmoqty) moqty
from pwrkf2mv a, mitbalc0 b
where a.pafidt between :p_startdate and :p_enddate
and a.ppdept = nvl(:p_dept,a.ppdept)
and a.prodno = nvl(:p_prodno,a.prodno)
and a.ppname like '%'||:p_proddesc||'%'
and rtrim(a.prefno) is not null
and rtrim(b.mbsttx) is not null
and a.pmfaci = b.mbwhlo
and a.prodno = b.mbitno
group by a.ppdept, b.mbsttx, to_char(to_date(a.pafidt,'YYYYMMDD'),'Y')||to_char(to_date(a.pafidt,'YYYYMMDD'),'WW')
order by a.ppdept, yrweek, b.mbsttx;
Siti

Answer 1

Hi Siti,
Is your table goes through frequent update and delete statements? if YES=>
Free blocks created during this operation may dgrade the performance during full
Tbale scan.
If you are using Oracle 10g, you can shrink the segments. But first enable the row movement
sql> alter table emp enable row movement;
http://www.oracle.com/technology/oramag/oracle/05-may/o35tuning.html
JAI HIND
Darshan