Performance problem with sproc and out parameter ref cursor

Question

Hi
I have sproc with Ref Cursor as an OUT parameter.
It is extremely slow looping over the ResultSet (does it record by record in the fetch).
so I have added setPrefetchRowCount(100) and setPrefetchMemorySize(6000)
pseudo code below:
string sqlSmt = "BEGIN get_tick_data( :v1 , :v2); END;";
Statement* s = connection->createStatement(sqlStmt);
s->setString(1, i1);
// cursor ( f1 , f2, f3 , f4 , i1 ) f for float type and i for interger value.
// 5 columns as part of cursor with 4 columns are having float value and
// 1 column is having int value assuming 40 bytes for one rec.
s->setPrefetchRowCount (100);
s->PrefetchMemorySize(6000);
s->registerOutParam(2,OCCICURSOR);
s->execute();
ResultSet* rs = s->getCursor(2);
while (rs->next()) {
// do, and do v slowly!
}

Answer 1

Hi,
I have the same problem. It seems, when retrieving cursor, that "setPrefetchRowCount" is not taking into account by OCCI. If you have a SQL statement like "SELECT STR1, STR2, STR3 FROM TABLE1" that works fine but if your SQL statement is a call to a stored procedure returning a cursor each row fetching need a roudtrip.
To avoid this problem you need to use the method "setDataBuffer" from the object "ResultSet" for each column of your cursor. It's easy to use with INT type and STRING type, a lit bit more complex with DATE type. But until now, I'm not able to do the same thing with REF type.
Below a sample with STRING TYPE (It's assuming that the cursor return only one column of STRING type):
try
  l_Statement = m_Connection->createStatement("BEGIN :1 := PACKAGE1.GetCursor1(:2); END;");
  l_Statement->registerOutParam(1, oracle::occi::OCCINUMBER, sizeof(l_CodeErreur));
  l_Statement->registerOutParam(2, oracle::occi::OCCICURSOR);
  l_Statement->executeQuery();
  l_CodeErreur = l_Statement->getNumber(1);
  if ((int) l_CodeErreur     == 0)
    char                         l_ArrayName[5][256];
    ub2                          l_ArrayNameSize[5];
    l_ResultSet  = l_Statement->getCursor(2);
    l_ResultSet->setDataBuffer(1, l_ArrayName,   OCCI_SQLT_STR, sizeof(l_ArrayName[0]),   l_ArrayNameSize,   NULL, NULL);
    while (l_ResultSet->next(5))
      for (int i = 0; i < l_ResultSet->getNumArrayRows(); i++)
        l_Name = CString(l_ArrayName);
l_Statement->closeResultSet(l_ResultSet);
m_Connection->terminateStatement(l_Statement);
catch (SQLException &p_SQLException)
I hope that sample help you.
Regards