Data engineering·Modelling for analysis
a bank account has three owners, so you cannot put an owner key on the fact without triple-counting the balance.
Bridge table
Also calledmany-to-many bridge, allocation table
An intermediate table resolving a many-to-many relationship between a fact and a dimension, often carrying an allocation weight. It is the honest way to model shared ownership, multi-valued attributes and hierarchies of variable depth. It is also a fan trap with a licence, so it usually ships with a weighting column precisely so that sums can be made to add up to a hundred percent.