KNOWLEDGE BASE

Error "Unable to run input node: Wait for cache write operation has terminated due to a failed write." When Connecting to SAP HANA in Tableau Prep


Published: 22 Aug 2019
Last Modified Date: 22 Aug 2019

Issue

When connecting to a SAP HANA view containing a date variable using Tableau Prep, the profile pane does not show any data and the following error occurs:

"Unable to run input node: Wait for cache write operation has terminated due to a failed write."

Environment

  • Tableau Prep Builder
  • SAP HANA

Resolution

This issue (ID: 95225) is currently under investigation. In the meantime please use one of the following workarounds:

Option 1

Write Custom SQL to connect to the view from Tableau Prep Builder. For more information on how to do this, please see: Connect to a custom SQL query

Option 2

  1. Connect to the same view in Tableau Desktop.
  2. Click Data > Convert to Customer SQL in Tableau Desktop to generate SQL needed to connect to view
  3. Copy this SQL and paste it into a custom SQL connection in Tableau Prep Builder. For more information on how to do this, please see: Connect to a custom SQL query

Cause

This error is caused by the following behaviours:
  • Date variables aren't properly encoded in queries from Prep
  • Variables with values different from the alias displayed in the UI select lists incorrectly use the alias in the query.
Did this article resolve the issue?