[viewobject tuning] setMaxFetchsize and setFetchSize questions

Question

In a ViewObject, inside the BC Wizard, there is a Tuning section where in you specify how data are retrieved on the database; Rows In Batches Of, At MOst One, No Rows.
When choosing No rows on the wizard, is it equivalent to calling setMaxFetchSize(0) - set it to zero?
Now when I set it to rows In Batches of 10. I have a viewobject with a query returning 235 rows. I have overriden to createRowFromResultSet method of the ViewObject class and inserted a log there to check how many times the createRowFromResultSet method is called after i execute the query. I noticed that the log prints 235 times. so meaning it creates 235 rows. I was expecting that it will print 10 times as I set the VO tuning paremeter to Rows in Batches of 10. and then just create another 10 when i traverse to the 11th row.
Why is that? How does the tuning work here?

Answer 1

Anton,
The batch size is how many rows are retrieved in a round trip to the database.
I am looking at the 11g tuning screen right now. The options are "all rows" or "only up to row number" - that should be obvious.
The next option is the batch size (10 in your case) - meaning that 10 rows will be fetched in a single DB call.
The final option "as needed" or "all at once" - the "all at once" should retrieve all 235 rows, but in batches of 10 (24 database round-trips).
Looking at the 10g screen (you don't mention which you are using), the organization is a bit different. but the concept is the same.
The question is, do you have "all at once" or "as needed" as your option? If you have all-at-once, then in any case, I would expect all 235 rows to be fetched initially, but in batches specified by the batch size.
John