I'm using ServiceNow Rest API to pull the data. It seems there is a limit on Data extraction from servicenow to QLIK. How did you create multiple connections to pull the entire data set from a table( Example: Incident Table).Please let me know.
I think that it is not a good idea to connect the reporting tool directly to a live ServiceNow instance. Not only it can affect the production environment but it will be simply too slow to download high volumes of data for each report execution.
The preferred way is to build an on-premise read-replica (i.e. a mirror database) and connect QlikSense to this local database. It will be much faster and your ServiceNow won't be affected.
You could use tools such as SnowMirror to extract the data from ServiceNow (or Salesforce).