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DB Performance: Star Schema (SS)<br />
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In general, Dimension tables have a very small number of rows<br />
compared to a Fact table<br />
POS Transaction Fact Table has 9 columns, 40 byte rows<br />
Maximum size of a POS table on an inexpensive PC might need<br />
a few hundred GB of disk, which would amount to 5 billion rows<br />
Dimension tables are much smaller: few thousand rows in Date,<br />
Store Dimensions, 100s in Promotion, few million in Product<br />
Practitioners keep Fact tables lean,Foreign Keys, TID and<br />
Measures, have many descriptive columns in Dimension Tables<br />
E.g. Product Dimension might have: ProdKey (artificial key),<br />
Product Name, SKU (natural key), Brand_Name, Category<br />
(paper product), Department (sporting goods), Package_Type,<br />
Package _Size, etc<br />
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