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Bug 363673

Summary: BIRT Native Excel Emitter Performance Issue
Product: z_Archived Reporter: Raghava <raghava.javvaji>
Component: BIRTAssignee: Birt-Data-inbox <Birt-Data-inbox>
Status: NEW --- QA Contact: Sissi Zhu <szhu>
Severity: critical    
Priority: P3 CC: bluesoldier, jouyang, raghava.javvaji
Version: unspecified   
Target Milestone: Future   
Hardware: PC   
OS: Windows XP   
Whiteboard:

Description Raghava CLA 2011-11-14 01:45:22 EST 
Build Identifier: 

I have been using Birt2.6.2 since long time. Recently I started generating excel reports with huge data(say 13lack rows). Here problem is reports are hanging in Birt and after few hours, failing with gc overload limit exceeded error. It looks like emitter is creating n number of data instances and they are not eligible for garbage collection until or unless count of objects hits max rows limit per page(it is 60k usually).We Integrated Birt with apache POI to generate 2007 excel file. So in our case,max row limit is 1048576.My max heap space limit is 10G.If I am not wrong,It is wise to flush the data instead of holding it in memory as we have nothing to do with data(sorting,ordering etc).It will help us to cut down heap memory usage. we enabled pagination once,Interestingly report got finished very quickly.

Reproducible: Always

Steps to Reproduce:
1.Create a report design using table with more than 12 rows
2.Have TSV file with 13lack rows
3.Try generating excel report
Comment 1 Raghava CLA 2011-11-14 01:48:07 EST 
We can reproduce same issue with Birt 3.7 as I have not seen any emitter code changes respectively.
Comment 2 Jun Ouyang CLA 2011-12-15 01:09:58 EST 
User should avoid outputting too much content into 1 single sheet by:
1. set proper page break
2. enable multiple sheet option(excelRenderOption.multipleSheet=true).

Maybe we should prompt user that the report is too big for Excel when OutOfMemory occurs, or just document this issue.
Comment 3 Jun Ouyang CLA 2011-12-15 01:12:50 EST 
Sorry, "multiple sheet" feature is not provided in OS Excel emitter yet.