A data warehouse is a structured repository of company data, consolidated from multiple operational sources (ERP, POS, CRM, legacy systems, external files), optimised for analysis and reporting rather than transactional operation. It is the environment where BI shines: the complex queries that would crush an ERP in production run in a data warehouse in seconds.
The data warehouse differs from the data lake. The data warehouse works with structured data, a relational model (star schema, snowflake), and is populated by periodic ETL/ELT processes; the data lake accepts unstructured data (logs, images, free text) and defers structuring to query time. For most Portuguese industrial and commercial companies, a well-designed data warehouse solves 90% of analytical needs.
In MyBusiness-ITV, Qlik operates on an associative model that consumes data from the client's data warehouse (or directly from the MULTI ERP in simpler implementations). Maintaining the data warehouse — ETL, performance tuning, data governance — is part of the INFOS service.