You need to create a data loading pattern for a Type 1 slowly changing dimension (SCD). Which two actions should you include in the process? Each correct answer presents part of the solution. NOTE…

Question

Options

• AUpdate rows when the non-key attributes have changed.
• BInsert new rows when the natural key exists in the dimension table, and the non-key attribute
• CUpdate the effective end date of rows when the non-key attribute values have changed.
• DInsert new records when the natural key is a new value in the table.

• A
  88% (15)
• B
  6% (1)
• C
  6% (1)

Explanation

A Type 1 SCD strategy overwrites changed attribute values with no history retention. The process requires exactly two actions: (A) updating existing rows when non-key attributes have changed - this is the 'overwrite' behavior defining Type 1; and (D) inserting new records when a natural key value is new to the dimension table - this handles genuinely new dimension members. Option B describes Type 2 behavior (inserting a new row when a key already exists to preserve history). Option C (updating effective end dates) is also Type 2 behavior used to close out superseded historical records. Neither B nor C belongs in a Type 1 pattern.

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