data warehouse - Should all dimension values be used in the fact table? -


im modeling data warehouse has 6 dimension. 1 of these dimensions client, has around 600k rows, , others such accounts , products. made estimation of number of rows of fact table multiplying cardinality of each dimension table, giving 1*10^12 rows result. question is, if client doesnt have product, there gonna row product (with cero value in fact table), or there wont row @ all? need information know if aproximation upper boundary number of rows, or exact number of rows.

you not need entry each dimension combination.

typically fact table (or cube) small compared theoritical size (i.e., multiplication of dimension's cardinalities). theoritical number of rows (or cells) can very large relative small number of dimensions (e.g., time, products, geography, customers, sales, etc...). known cube's sparsity; olap engines (e.g., iccube, ssas, etc...) typically built handle efficiently sparsity.


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