OutOfMemory Nested Tables Using Filters

elbeau

Our product allows customers to add BIRT report design files and run them in-process in our system. One such file is causing OutOfMemory errors and it's hard to understand why. I've already solved the problem by creating the tables another way, but I'd really like to understand why this didn't work in the first place so I can give good advise to customers wanting to do similar things in the future.

The report runs off of a flat-file data source with multiple CSV tables. The report had one table nested inside another, and the outer table would set a BIRT variable that the inner table would use in a filter to get just the rows that the inner table wanted. BIRT's memory limit is set to 2048. The data files the report ran off of were relatively small, there were three tables, and the largest on was 2,200 rows, but when you ran the report in the BIRT designer the CPU would just spin and the memory would keep building up and up until it got the OutOfMemory error. The report ran fine on a smaller (1/7 size) data set.

Do nested tables using filters not get cleaned up properly or something? What am I missing here? Simply deleting the nested table made the report run, so it definitely has something to do with the nested table's filter that uses the variable set by the outer table.

Any ideas would be greatly appreciated.

Thanks

mwilliams

Hi elbeau,

This is probably because BIRT is bringing in the entire dataSet each time the nested table is called and filtering it down. This takes up a lot of memory and processing time. If you were using SQL and could take advantage of the dataSet parameter binding, this probably wouldn't have been an issue. The newest versions may help with this issue because of better caching. What BIRT version are you using?