Hello, I have got the problem when exporting huge data with net.sf.jasperreports.engine.export.ooxml.JRXlsxExporter.JRXlsxExporter(), runtime will grow exponentially in comparison to the amount of data. Query is fast, Export to PDF o PREVIEW is fast. Using JRSwapFile is no solution. We are using JR 4.7.0, but I have already tried with JR 6.0.0. It's not better. This problem is reported quite often in jasperreports community for some years, but I found no satisfying answer. Will there be a solution in the near future? What does TIPCO say to this problem, is it a job for you? Thank you Norbert