The ETL design pattern prescribes transformation from staging tables to a central data warehouse data model, followed by extracting data from the data warehouse data model to data marts.
Are there any limitations, and what could go wrong, with transforming data from the staging tables directly into a data mart? (e.g., skipping the data warehouse data model)
Doing that would save a lot of development time and effort in my view. It would also save time when the data warehouse model changes. Data history could be accomplished in the staging layer.
The data warehouse my organisation is currently developing (based on the ETL pattern) seems to take ages. We do need a data warehouse/business intelligence solution, but it doesn't need to be extremely advanced; we are a midsize organisation (1000+ employees).
Would using ELT instead of ETL save development time? (e.g., writing SQL queries for the transformation instead)