Oracle Store Procedure communicate with ADO

Question

I am writing an application for OLTP. The application also need to let user search for data and display in grid.
I want to store the queries in Package. I am using ADO 2.5 and VB6.
Having tested putting things and Stored Proc and return a Cursor as output parameter in Oracle, I used ADO's command object to call the stored proc. But the performance of recordset.Open(ADOCommand, ..) is much worser than directly calling the recordset.Open(connection, SQL) to get the recordset.
I tried query for 12000 records with only few fields, using stored proc populated the recordset (client side, static) in 12 sec. Using direct SQL query do it in 6 sec. The most problem is that with ADOCommand, it fill up my 100MB memory (so strange!!!), while direct SQL query only used 2MB...
I wonder whether it's the fault of my calling method or not.
My stored proc is like below
procedure MySP(p1 varchar2, p2 varchar2, p3 varchar2, pcur OUT T_REF_CUR) is
begin
open pcur for
select field1, field2, field3 from MyTable;
end;
My VB program retrieve data like below
dim objcmd as new adodb.command
dim objrst as new adodb.recordset
set objcmd.activeconnection = MyGlobalPresistantConn
objcmd.text = " call MySP{?,?,?} " 'the syntax may not be correct here, because I type it in a free text editor only
objcmd.parameters.append p1 'p1,2,3 are parameters object
objcmd.parameters.append p2
objcmd.parameters.append p3
objrst.open(objcmd, , adStaticCursor)

Answer 1

here's a couple of ideas :
- tuneup your PL/SQL code, make sure it runs fast from SQL * Plus itself. Maybe consider putting hint like
SELECT /*+ FIRST_ROWS +/ FIELD1, FIELD2 ...
- In VB 6 using objects good idea is to create them like:
Dim objcmd as adodb.command
Dim objrst as adodb.recordset
Set objcmd = New adodb.command
Set objrst = New adodb.recordset
Not like :
Dim objcmd as New adodb.command
Dim objrst as New adodb.recordset
when you done, close objects, connections
and then destroy it :
Set objcmd = Nothing
Set objrst = Nothing
(this has to do something with memory handling, etc.)
- try to use 'adForwardOnly' constant as seems to be the fastest option ...
- If nothing works look online for good code samples for exactly your case in PL/SQL ref-cursors and VB 6, ADO 2.5