To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) The uniqueness value is a component of the row hash value - This option is incorrect. The uniqueness value is not a component of the row hash value. The row hash value is calculated based on the primary index value.
Option B) In a table that has a NUPI, all rows with the same NUPI value are distributed to the same AMP - This option is correct. In Teradata, when a table has a Non-Unique Primary Index (NUPI), all rows with the same NUPI value are distributed to the same Access Module Processor (AMP). This helps in efficient data retrieval and query processing.
Option C) Two Primary Index values that hash to the same row hash value are called hash synonyms - This option is correct. In Teradata, when two different primary index values hash to the same row hash value, they are referred to as hash synonyms. This can lead to data skew and imbalanced data distribution.
Option D) The output of the hashing algorithm is called the hash map - This option is incorrect. The output of the hashing algorithm is called the row hash value, not the hash map.
The correct answer is B, C. Option B is correct because it explains the behavior of NUPI in Teradata, and Option C is correct because it explains the concept of hash synonyms in Teradata.
