Hi, I have used the BigGridDemo scenerio for my project. It works perfectly. However, i try to set the column width, couldn't find any good tutorial out there. Please help me or show me where i can learn how to do that. Thanks, DT.
Sanjay Madhavan wrote: > > Yegor, > > I was happy to see that the 3.6 version of POI had some significant memory > optimization work done in XSSF. > > However after testing the 3.6 code I find the optimization is still > insufficient for our usage. > > Our main use for the Excel 2007 format is to exceed the 64K row limit with > Excel. > > Unfortunately in most of our real world reports even with the 3.6 codebase > the memory usage remains outrageous for XSSF and most often leads to > server > crashes due to out of memory errors. > > Is there any plan on re-designing the XSSF implementation since the > current > implementation does seem to have significant issues. > > Thanks > > /sanjay > > On 20 July 2009 12:02, Yegor Kozlov <[email protected]> wrote: > >> >>> But the question remains. Are there any plans to fix the memory usage >>> for >>> the EXCEL 2007. The memory requirement seems to be unbelievably high. >>> >>> >>> >> POI OOXML is powered by Apache XMLBeans. It made development much quicker >> and easier but with the drawback of high memory requirement. We do have >> plans to reduce memory usage but I'm not sure how much can be done. >> >> Yegor >> >> >> Regards >>> /sanjay >>> >>> On Fri, Jul 17, 2009 at 7:34 PM, Yegor Kozlov <[email protected]> wrote: >>> >>> Use direct streaming in XML. A sample implementation can be found at >>>> >>>> >>>> >>>> http://svn.apache.org/repos/asf/poi/trunk/src/examples/src/org/apache/poi/xssf/usermodel/examples/BigGridDemo.java >>>> >>>> It's not a ready-to-use API, rather a proof of the concept. To use more >>>> advanced features (merged cells, custom height or width of rows and >>>> cells, >>>> conditional formats, etc.) you will need to study the SpreadsheetML >>>> documentation and enhance the demo. >>>> >>>> Yegor >>>> >>>> >>>> We have been using POI for EXCEL generation for a number of years >>>> >>>>> successfully. >>>>> >>>>> Recently we started using the EXCEL2007 (OOXML) generation >>>>> capabilities >>>>> of >>>>> POI 3.5. >>>>> The reason we wanted the OOXML capabilities was to generate excel >>>>> reports >>>>> with more than 64K records. >>>>> >>>>> As soon as we started using the OOXML/POI 3.5beta5 version we started >>>>> having >>>>> enormous memory issues that pretty much makes POI unusable for our >>>>> scenarios. >>>>> >>>>> We regularly generate reports with 20K -50k records and this was >>>>> handled >>>>> easily with the excel format. >>>>> >>>>> The OOXML format with poi uses humongous amounts of memory even for >>>>> modest >>>>> number of records. >>>>> >>>>> For example we generated a report with 14K records and unless we >>>>> allocated >>>>> 1.2GB of heap space to the Java VM the report could not complete. The >>>>> usual >>>>> error is the Java VM crashes with a not enough heap space error. >>>>> >>>>> I would appreciate if anybody could advise us on how to avoid this >>>>> memory >>>>> situation. >>>>> >>>>> Also why does POI 3.5 keep everything in memory? >>>>> >>>>> Are there any plans to rework POI 3.5 to better manage generation of >>>>> large >>>>> excel 2007 worksheets? >>>>> >>>>> >>>>> Thanks and regards >>>>> >>>>> /Sanjay >>>>> >>>>> >>>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: [email protected] >>>> For additional commands, e-mail: [email protected] >>>> >>>> >>>> >>> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> >> > > -- View this message in context: http://old.nabble.com/Poi-Excel-2007-and-Large-number-of-data-records-tp24534358p27660806.html Sent from the POI - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
