Mike you is very fast with answering:)
Thank you!! I will try it out tomorrow
Nikolai
2006/8/2, Mike Kienenberger <[EMAIL PROTECTED]>:
I'm not quite answering your specific question, but some of the things
people have done in the past is to throw out the old Cayenne Data
context periodically (every N number of objects written out) and
create a new one.
Also, you can use performIteratedQuery instead of performQuery to only
fetch a limited number of records for processing at a time.
On 8/2/06, Nikolai Raitsev <[EMAIL PROTECTED]> wrote:
> Hello all, I hope, this is my last question...:)
>
> Example:
>
> I would like to perform a copy from table 1 ("InterfaceTable") to table
2
> ("BaseTable").
>
> On both tables i have defined business objects (with cayenne modeler,
> InterfaceObj and BaseObj).
>
> BaseObj possesses plausibility (validate) methods with which his
attributes
> are examined for correctness.
>
> The copying process runs like that:
>
> //open DataContext
> dataContext = DataContext.createDataContext ();
>
> //read InterfaceData
> SelectQuery selQueryInterface = new SelectQuery(sClassNameInterface);
> dataObjectsInInterface = new DataObjectList(dataContext.performQuery
> (selQueryInterface));
>
> //read BaseData
> SelectQuery selQueryBasis = new SelectQuery(sClassNameBasis);
> dataObjectsInBasis = new DataObjectList(dataContext.performQuery
> (selQueryBasis));
>
>
> int nSizeBasisTable = dataObjectInBasis.size();
>
> int nSize = dataObjectsInInterface.size();
>
> //transfer data
>
> for(int i = 0; i<nSize; i++)
> {
> dataObjectInt = (CayenneDataObject)
dataObjectsInInterface.get
> (i);
>
> if(nSizeBasisTable > 1) //here possible updates
> {
> if(locateInBasisData())//locate BaseObj with primary
keys
> from dataObjectInt, update if a BaseObj was found
> {
> dataObjectBasis.setValuesFromInterface
(dataObjectInt);
> }
> }
> else//here inserts
> {
> dataObjectBasis =
>
(MaDataObjectBasis)dataContext.createAndRegisterNewObject(sClassNameBasis) ;
>
> dataObjectBasis.setValuesFromInterface(dataObjectInt);
> countInsert++;
> }
>
> //Validate Data
> try
> {
> ValidationResult validationResult = new ValidationResult();
>
> dataObjectBasis.validateForSave(validationResult);
> if(validationResult.hasFailures())
> {
> //do something with failures
> }
>
> }
> catch(ValidationException vex)
> {
>
> }
>
> }
>
>
> //and now commitChanges
> dataContext.setValidatingObjectsOnCommit(false);
> dataContext.commitChanges();
>
> //end
>
> in section //read BasisData are gotten all data from the "BaseTable" so
that
> locateInBasisData becomes fast (otherwise i have for every object from
> "InterfaceTable" a select query on "BaseTable")
>
> With such procedure I can process problem-free 30,000 data records (on
both
> tables) under 10 sec without a large memory capacity.
>
> but...
>
> It can occur in extreme cases by far more data records. 500,000,
1,000,000…
> and so on
>
> Of course, i would like use my procedure for small data sets and for
large
> data sets. So that the memory in case of large data sets does not run
out, i
> need a possibility to cache the data local in files.
> Is that possible with Cayenne? I mean, is possible to set cayenne
> (property?) so that their ObjectStore becomes out in files and work
with
> that?
>
> I have read the tips here:
> http://cwiki.apache.org/CAYDOC/performance-tuning.html, but it is not a
> solution for very large datasets (that memory can run out)...
>
> i hope my question is clear, if not, please mail me;)
>
> Thanks at all,
>
> Nikolai
>
> P.S. I use standard environment, not a app. or web server
>
>
