Is there any condition we store degenerate dimension in separate table?

When the cardinality of column value is high, instead of maintaining a separate dimension and having the overhead of making a join with fact table, degenerated dimensions can be build, Example:  a purchase order number.  These columns store something that we want to have (the purchase order number), but to create an empty dimension table would only slow things down.  So, to ensure we don't feel bad about breaking the "only a measure or a dimension in the fact table" rule, we just CALL them dimensions- even without the table

A degenerate dimension is not normally stored in its own separate table since most of the interesting attributes about it would be stored in another table for analytics