I haven't experimented with that much (so no idea which drivers take
advantage of that and which would simply ignore it), but that would
indeed be a useful parameter for ResultIterator scenario. So maybe
open a feature request in Jira?
Andrus
On May 15, 2009, at 5:45 PM, stefcl wrote:
Thanks,
Since the beginning I am convinced that resultiterators are the
right way,
unfortunately they are useless if the jdbc driver loads everything
in memory
before giving access to the resultset.
I hope there's something to do about it because it's a showstopper
for me.
Robert Zeigler-6 wrote:
Take a look at paginated queries (which isn't /quite/ what you want,
but may help you):
http://cayenne.apache.org/doc/paginated-queries.html
As well as ResultIterator:
http://cayenne.apache.org/doc/iterating-through-data-rows.html
Robert
On May 15, 2009, at 5/159:21 AM , stefcl wrote:
Thanks but my problem is not related to paging.
I would like to be able to execute a select query which returns
approx
100000 rows with a single selectQuery and process them one by one,
while
keeping only a few of them in memory (using the resultiterator).
In jdbc, Statement.setFetchSize(1000) tells the jdbc driver to
retrieve
results from the database 1000 at a time and ask for the next 1000
as you're
iterating the resultset. Otherwise its default behavior is to
retrieve the
100'000 rows in memory before you can start iterating the resultset.
It's not the same thing as inserting a TOP or a LIMIT clause in the
query.
Any help appreciated
Andrey Razumovsky wrote:
Hi,
Yes of course. You can use SelectQuery.setFetchLimit(int) and
setFetchStart(int) methods. They do just that.
Andrey
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