Hello, I have a related question. Is it possible to delete a record using a data row, without having to instantiate first a data object via context.objectFromDataRow() (as it is seen in the code example below)? If possible, how? Thanks in advance, Péter
-----Original Message----- From: Andrus Adamchik [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 06, 2007 5:59 PM To: user@cayenne.apache.org Subject: Re: AW: out of memory Peter is right in his assessment that DataContext would cache all its loaded objects (especially since they get in a dirty state via 'deleteObject'). To solve this problem, you may use a loop counter and commit and throw away the DataContext every X iterations (e.g. every 1000 or so). This will clear the memory. On top of that, if you want all 800000 deletes to be processed as a single transaction, you may do the above, but also wrap that code in a manual transaction: http://cayenne.apache.org/doc/understanding-transactions.html Andrus On Mar 6, 2007, at 6:51 PM, Peter Schröder wrote: > i experienced the same problem. i thinks this was because of using > > objectFromDataRow() > > which puts the object into the dataRow-cache and will result in out- > of-memory errors. > > as a workaround i used the raw-object/data-row object from the query. > > > -----Ursprüngliche Nachricht----- > Von: marco turchi [mailto:[EMAIL PROTECTED] > Gesendet: Dienstag, 6. März 2007 17:48 > An: user@cayenne.apache.org > Betreff: out of memory > > Dear experts, > I run a code, where I read 800.000 records from a database, but what I > obtain is the error "out of memory: heap....". > I use the following cayenne commands: > > Expression exp_date = Expression.fromString("dateRetrieval >= > $start_d and dateRetrieval < $end_d and type=$type");//("type=$type"); > Map parameters =new HashMap(); > parameters.put("end_d", "2006-03-09" ); > parameters.put("start_d", "2005-10-07" ); > parameters.put("type", "Job"); > exp_date = exp_date.expWithParameters(parameters); > final SelectQuery feedsquery = new SelectQuery(FeedsAll.class, > exp_date); > int count=0; > try{ > > final ResultIterator it_q = context.performIteratedQuery > (feedsquery); > while(it_q.hasNextRow()){ > > final Map row = it_q.nextDataRow(); > final FeedsAll obj = (FeedsAll) > context.objectFromDataRow(FeedsAll.class, new DataRow(row), true); > ..... > context.deleteObject(obj); > } > } > catch(Exception e){ > //System.out.println("Fatal Error: "+e); > log.error("Fatal Error: ",e); > log.info(e.getStackTrace()); > } > > what is it wrong? I understood that using the performIteratedQuery, I > could read a huge number of records without memory problem. > Can you help me? > > Thanks a lot > Marco >
