On 13/12/12 12:18am, Simon Schneider wrote:
Hi list,
my task is to fetch and process a large amount of objects. Reading the
documentation my best choice
seemed to do a dataContext.performIteratedQuery(query). The problem is that I
get a Java Heap Space
error, on executing this statement. Now it seems to me the problem is that
performIteratedQuery loads
all data into a ResultSet.
My question is how to handle such cases, is there any best practice? Would it
be ok to use a paginated
query. Then unregistering processed objects from the DataContext they belong to
and also removing
them from the array that resulted from the paginated query.
By the time you step through to the end of the results, even with a paginated
query you will have read every object into RAM. However paginated queries are a
really convenient way to fetch even millions of rows where you don't
necessarily want to access every object (eg. when you want to display a
scrollable list of results and you only need to resolve the objects you can see
in the current viewport).
As Michael says, an option is to read in the data in batches into different
Contexts.
Ari
--
-------------------------->
Aristedes Maniatis
GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A
