A degenerate dimension is:
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an attribute of a fact which quailifies as a dimension
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stored in the fact table
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has no surrogate keys
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has fixed values that cannot be generated outside the fact
A degenerate dimension is a dimension attribute that has no dimensions of its own (like order number or invoice number) and is therefore stored directly in the fact table rather than in a separate dimension table. Options A and B correctly define this - it's an attribute that qualifies as dimension but is stored in the fact table for efficiency. Option C is incorrect because degenerate dimensions typically have no surrogate keys (they use natural keys). Option D is incorrect - values are generated outside the fact (from source transactions).
This is a multi-select and the DB's correct set is incomplete. A degenerate dimension is a dimension key (e.g. an invoice, order, or transaction number) that lives in the fact table but has NO associated dimension table. Correct properties: it is an attribute in the fact that acts as a dimension (520299), and it is stored in the fact table (520300) — both already marked. Additionally, 'has no surrogate keys' (520301) is a textbook-accurate property: because there is no separate dimension table, a degenerate dimension has no surrogate key — it is just the operational/natural key sitting in the fact row. So 520301 should also be TRUE. Option 520302 ('fixed values that cannot be generated outside the fact') is false — degenerate keys typically originate in source/operational systems.