Prepared=True Not working. Parse:Execute ration is one in tkprof report

Question

Hello,
DB Version 9.2.0
OS NT
Provider: OraOLEDB 9.2.0.1.0
I have a small .NET application. I use bind variables all overe my application. But my parse:execute ratio is 1 for some of all SELECT statements. There are many softparses in my application. I have also set session_cached_cursors.
While using ADODB command object I set the "Prepared" parameter to true. But even though
there are many parses.
Heres is the simple block of code ..
strCmd = "SELECT DISTINCT TO_CHAR(exp_date,'Month') Months, " _
TO_CHAR(exp_date,'MM') MM FROM expenses ORDER BY MM"
cmd1 = New ADODB.Command()
cmd1.ActiveConnection = cConn
cmd1.CommandText = strCmd
cmd2 = New ADODB.Command()
cmd2.ActiveConnection = cConn
cmd2.CommandText = strCmd
cmd2.Prepared = True
For intLoop = 1 To 4
cmd1.Execute()
Next intLoop
For intLoop = 1 To 4
cmd2.Execute()
Next intLoop
Heres the tkprof trace output
SELECT DISTINCT TO_CHAR(exp_date,'Month') Months, TO_CHAR(exp_date,'MM') MM
FROM
expenses ORDER BY MM
call count cpu elapsed disk query current rows
Parse 8 0.00 0.00 0 0 0 0
Execute 8 0.04 0.06 0 0 0 0
Fetch 8 0.01 0.01 0 56 0 226
total 24 0.06 0.07 0 56 0 226
Misses in library cache during parse: 1
Optimizer goal: CHOOSE
Parsing user id: 62
Rows Row Source Operation
23 SORT ORDER BY
23 TABLE ACCESS FULL EXPENSES
Logically it should be one parse and 8 execution. Will anybody please suggest me, how do I minimise the number of parses?
Thanks in advance
Sameer

Answer 1

"db file parallel read" is likely to be associated with something like index prefetching.
See:
http://www.freelists.org/post/oracle-l/RE-Calculating-LIOs,11
http://aprakash.wordpress.com/2012/05/29/index-range-scan-and-db-file-scattered-read-as-session-wait-event/
http://jonathanlewis.wordpress.com/2006/12/15/index-operations/
Tune the SQL.
Review the execution plan.
Check whether the statistics are accurate.
Review whether the index hint (and others that we can't see) is appropriate.