How to improve performance of saving bulk data in grails?

Question

I am saving bulk data in database however it takes lots of time to save 3000 rows so I thought of clearing the session every-time I save the data.I am unable to retrieve the session object.

Error:

Stacktrace follows:
Message: Cannot invoke method getCurrentSession() on null object

Code:

def importUpload() {
        def sessionFactory;
        def session = sessionFactory.getCurrentSession()
        User currentUser = springSecurityService.getCurrentUser();
        def file = request.getFile('file')
        InputStream is =file.getInputStream()
        XSSFWorkbook workbook = new XSSFWorkbook(is);
        int sheet_Num = workbook.getNumberOfSheets();
        for (int sheetNo = 0; sheetNo < sheet_Num; sheetNo++) {
            Sheet sheet = workbook.getSheetAt(sheetNo);

                for (int row = 1; row < sheet.getLastRowNum(); row++) {
                PrimaryOwner = sheet.getRow(row).getCell(1);
                SecondaryOwner = sheet.getRow(row).getCell(2);
                BusinessUnit = sheet.getRow(row).getCell(3);
                ProfileTitle = sheet.getRow(row).getCell(5);

                def job = Job.findByName(ProfileTitle);
                if(!job){
                    Job jobObj=new Job();

                    jobObj.account = currentUser.account;
                    jobObj.contactName = PrimaryOwner;
                    jobObj.secondaryContactName = SecondaryOwner
                    jobObj.buisnessUnit = BusinessUnit
                    jobObj.name = ProfileTitle
                    job = jobObj.save(failOnError:true,flush:true);
                    session.flush()
                    session.clear()
                }
}

Answer 1

Take a look at this blog: http://naleid.com/blog/2009/10/01/batch-import-performance-with-grails-and-mysql

I followed the guidance on it to flush and clear the session with good results. I combined that with some batch saving.

Something like this:

    SessionFactory sessionFactory //inject sessionFactory


void CreateBills(List<Statement> statements){
    statements.colate(100).each{List<Statement> batchedStatements ->
        batchedStatements.each{Statement statement ->
            new Bill(statement).save()
        }
        cleanupGorm()
    }
}

void cleanupGorm(){
    def session = sessionFactory.currentSession
    session.flush()
    session.clear()
    DomainClassGrailsPlugin.PROPERTY_INSTANCE_MAP.get().clear()
}