读《数据仓库工具箱：维度建模的完全指南》之第二章蜈蚣事实表

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Interestingly, while uncomfortable with denormalized dimension tables, some
modelers are tempted to denormalize the fact table. Rather than having a single
product foreign key on the fact table, they include foreign keys for the frequently
analyzed elements on the product hierarchy, such as brand,
subcategory, category, and department. Likewise, the date key suddenly turns
into a series of keys joining to separate week, month, quarter, and year dimension
tables. Before you know it, our compact fact table has turned into an
unruly monster that joins to literally dozens of dimension tables. We affectionately
refer to these designs as centipedes because the fact tables appear to have
nearly 100 legs, as shown in Figure 2.13. Clearly, the centipede design has
stepped into the too-many-dimensions trap.