I concur with Mike on the suggestion. Though I would recommend using vastly improved 4.0 API:
http://cayenne.apache.org/docs/4.0/cayenne-guide/performance-tuning.html#iterated-queries > As you iterate over your entire record set, you can convert the DataRows > into Cayenne objects In 4.0 you can iterate over objects. > Gather up 50 or 100 or 1000 In 4.0 you can use batch iterator to receive the stream already split in batches. Docs example actually has a typo. Batch iterator looks like this: try(ResultBatchIterator<Artist> it = ObjectSelect.query(Artist.class).batchIterator(context, batchSize)) { for(List<Artist> list : it) { ... context.commitChanges(); } } Andrus > On May 19, 2017, at 4:39 PM, Michael Gentry <blackn...@gmail.com> wrote: > > Hi Pascal, > > I suspect you need to utilize an iterated query: > > http://cayenne.apache.org/docs/3.1/cayenne-guide/performance-tuning.html#iterated-queries > > As you iterate over your entire record set, you can convert the DataRows > into Cayenne objects (see the section in the documentation above the > iterated queries documentation) in a *different* DataContext. Gather up 50 > or 100 or 1000 (whatever number feels good to you) in that second > DataContext and then commit them, throw away that DataContext and create a > new one. Repeat. This should keep your memory usage fairly constant and > allow you to process arbitrarily large record sizes. > > mrg > > > On Fri, May 19, 2017 at 9:27 AM, Pascal Robert <prob...@druide.com> wrote: > >> Hi, >> >> I’m still in my FileMaker -> MySQL migration project. This time, I want to >> migrate a FileMaker table who have 445 244 records in it. If I fetch >> everything into an object entity for each row, I’m getting a Java heap >> space problem, which is somewhat expected by the size of the result set. >> >> If I call setFetchLimit() with a 10 000 limit, works fine. FileMaker >> doesn’t support fetch limits, so I can’t do something on that side. >> >> Any tips?
