These are the types of questions which will help you understand how to fetch the data from various sources and link it together to achieve what the users want. They are mostly asked to a techno functional person or a database guy who understands the data sources:

• What are the different data sources required to gather all information?
• Do you have a data warehouse where all the data is collated?
• What ERP(enteprise resource planning software) is being used?
• Is there direct connectivity with the data source available, in terms of ODBC or OLEDB connection?
• If the data source is a cloud based system, can data be fetched using the web services?
• Do you need to connect to the raw tables, the views, or a cube to get the data?
• Do you have prebuild queries which can help to understand the base tables and fields, along with the logics, if any?
• Are there any standard reports available which can give you the data required?
• What are the list of tables required for reporting?
• What are the fields which are required?
• What are the linking fields, that is, the primary keys, foreign keys, and composite keys?
• What is the granularity of each of the tables?
• Does each table have the last modified timestamp?
• What are the fact tables and how many are required?
• What are the dimension tables?
• Are there field description available if there are generic fields?
• What are the logics which can be applied or are already available in database, to reduce the duplication of work?
• Do you have any documentation available which can show the data flow diagrams to understand the flow of the data?
• What is the size of the database and what will be the size of the reporting data?
• What is the time when the data fetching can be scheduled, so that a minimum load can be put on the transactional data source?
• Is there any limitation on the number of sessions/connectivity in a database?
• Is a slowly changing dimension required?
• How is the slowly changing dimension handled in the database?
• If the data source is going to be CSVs or text files or Excel files, how will it be shared with Qlik?
• Can the csv/text/excel files be uploaded in the database and then Qlik get access to them through the database, or do you want to upload them directly in Qlik?