The possible root cause for errors during extract are :

  1. Error in OBIEE due to the extraction of a large volume of data 
  2. Errors in OBIEE RPD for one or more columns in the selected tables/folders in OBIEE.  

To resolve this error, 

  1. You should limit the columns that are being imported.  

Extracting all columns might error out in OBIEE if your OBIEE RPD has errors in one of the columns in the selected tables.  OBIEE RPD could have errors such as "missing physical mapping" for some columns which are not used.  But since Tableau is querying on all the columns in a Table/Folder, the query will fail in OBIEE.   So, you should choose only a small number of columns for your query and hide the unwanted columns.

In Tableau you can do limit columns by using Hide Unused Columns in Tableau.  You should choose only a small number of columns for your query (in the worksheet) and hide the unwanted columns.  Then Tableau will query only the required columns in the table.     

2.  You should use filters to limit the amount of data coming into Tableau/Power BI/Qlik from OBIEE.  

Your OBIEE administrators might have set limits on the number of rows (e.g., 200,000) that can be queried.  OBIEE would error out if you are trying to extract a large number of rows beyond that limit.  

Please refer to the following article for further insight on this issue:
How to increase the number of rows fetched from OBIEE into Tableau or Power BI using BI Connector?

If you have tried and eliminated both these root causes for the error, please send us a clean set of log files for the error to support at biconnector dot com.  Please refer to the below article for log file generation:

How to generate a clean set of BI Connector log files for troubleshooting?