Unable to reduce Physical Reads

Question

Hi
Problem:
Need to reduce the Physical reads in Oracle 8.1.7
Information:
Optimizer_mode= Choose
Statistics will not be gathered.
Intially the cache hit ratio is 18%. At this point when we checked the SQL Statement
SELECT a32,
F_DOCNUMBER,NVL(a109,'BIWS') AS WorkFlow,
a147 AS Service_Subsidary,
a89 AS StaffInd,
a88 AS SubsidiaryInd
FROM doctaba
WHERE a94 = 'CCOC_CARDS_CCA_060824_6'
AND a40 IN ('3','4','5')
0 recursive calls
81 db block gets
5020 consistent gets
3909 physical reads
0 redo size
401 bytes sent via SQL*Net to client
311 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed.
Once we increase the Buffer Cache Hit Ratio to 90% We got the following
0 recursive calls
81 db block gets
3717 consistent gets
3576 physical reads
0 redo size
401 bytes sent via SQL*Net to client
311 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed.
But can you please advice how to reduce the Physical Reads further.
Note: Table DOCTABA is a Snapshot that is present in Other Database.
Please advice!!
Cheers
Ramkannan.A

Answer 1

Buffer hit cache ratios are totally meaningless as was proven many years ago by Connor's brilliant little utility that allows you to dial in any ratio you want.
The reason your are getting FTEs is because your totally antiquated version of the product, never supported during the current century, is that it thinks FTEs cost less than using any indexes that may (or may not) exist. You've not established in your email that there are any indexes or posted DDL or provided much of anything else that would be helpful.
I would think moving from the Jurassic to 10.2.0.4, or above, would be your first priority.