Qlik Compose: Error executing Schema Evolution

[Nanda_Ravindra]

Compose shows the below error when trying to enable schema evaluation:

SYS-E-ERRMSG, Error occurred while getting replicate last DDL timestamp: SYS-E-HTTPFAIL, Failed to retrieve query: java.lang.NullPointerException.

Schema evolution in Compose requires certain options to be turned on in the Replicate task(s) to detect all DDL changes that were made to the source database.

This error will occur if DDL History is not enabled in Qlik Replicate. 

To facilitate Schema evolution in Qlik Compose:

1. Open Task Settings
2. In the Metadata section, open Control Tables
3. Locate DDL History and enable it (see fig 1).
   
   fig 01
   
   

If you intend to scan all data sources (when performing schema evolution), then you must do this for all Qlik Replicate tasks moving data to the Landing Zone, even those with source endpoints that do not support schema evolution (e.g. Salesforce).