java heap error when using write to excel template node

Dear all,

Multiple data sources are processed and saved into multiple sheets in a single Exceltable

If executing the Write to Excel Template node multiple times, Java Heap Error appears

Circumstances:

Win10 Enterprise 64bit, 48 GB RAM, Office365 Enterprise, Knime. Latest updates installed.

How to reproduce:

copy all attached file to c:\temp

1.xlsx

java_heap_error.knwf

outbound_template.xlsx

outbound_template.xlsx

Open 1.xlsx in Excel 1st sheet

Copy row 2 100.000 times; so 100.000 rows are filled

Save 1.xlsx

(Step neccessary to go around upload limit)

load Workflow javaheaperror

Remark: For demo I have only one source reading this multiple times

execute node Write to Excel template Write Table Outbound sheet 1-> Operation is executed ok; Java Heap increases

execute node Write to Excel template Write Table Outbound sheet 2-> Operation is executed ok; time increases, Java Heap increases

execute node Write to Excel template Write Table Outbound sheet 3-> Operation is executed ok; time increases, Java Heap increases

execute node Write to Excel template Write Table Outbound sheet 4-> Operation is executed ok; time increases, Java Heap increases

execute node Write to Excel template Write Table Outbound sheet 5-> Operation fails

Questions:

Is it a bug?

Is there a way to relase the java heap memory?

Is there a better way to write to excel (Excel sheet will grow to 210 MB on disk at the end of the application)

Thx for help!

BR, Heinz