KNOWLEDGE BASE

Error "System error: Java heap space" When Exporting an output or Running a Tableau Prep flow


Published: 29 Aug 2018
Last Modified Date: 13 Aug 2020

Issue

When outputting or running a complex Flow in Tableau Prep, the following error might occur: 
"System Error: Java heap space" 

Environment

  • Tableau Prep Builder

Resolution

Choose either of the following two workaround in order to avoid the Java Heap Space error:

Option 1

Split out the flow into multiple, smaller flows.

Option 2

Increase the maximum heap size for the Java process within Tableau Prep Builder. Please see below for steps for the details:
  • Open Command Prompt on the machine where Tableau Prep Builder is installed.
  • Navigate to the installation directory of Tableau Prep Builder. For example: cd "C:\Program Files\Tableau\Tableau Prep Builder version xxxx\"
  • Launch the application with the command: "Tableau Prep Builder.exe" --java-options -Xmx16g
The above command will automatically open Tableau Prep Builder with a maximum heap size of 16GB of RAM. Please adjust this value for the hardware specifications of the machine where Tableau Prep Builder is installed.

Cause

It requires more resource to be able to execute the flow successfully.
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