TeraData Interview Questions - 2

Tuesday, December 4, 2007

12. Which statement is true if using NUPIs to accomplish data distribution?

  • Uniform row distribution is accomplished using UPIs.
  • The low-order 16 bits of the row hash are input to the hash map.
  • The increase of hash buckets has resulted in more hash collisions.
  • Duplicate NUPI values will produce the same row hash.

13. Which three statements are true for Primary Keys and Primary Indexes? (Choose three.)
  • They are both optional in a Teradata table.
  • They are conceptually the same.
  • They can be the same column.
  • They can contain unique data values.
  • They can be defined in a Create Table.

14. Which two statements are true of Teradata data distribution? (Choose two.)
  • manual distribution of the data
  • based on hashing of the Primary Key
  • based on hashing of the Primary Index
  • automatic distribution of the data

15. Which three statements are true about the way Teradata handles data access? (Choose three.)
  • Skewed data distribution does not affect data access.
  • The rows of each table are distributed among all AMPs based on the Primary Index of the table.
  • A table stored entirely on one disk offers improved access performance.
  • A full table scan accesses all AMPs in parallel.
  • If an index is referenced in a query, it is used unless a full table scan is determined to be more efficient.

16. What are two reasons for choosing a Unique Primary Index (UPI) verses a Non Unique Primary Index (NUPI)? (Choose two.)
  • A UPI guarantees even data distribution.
  • A UPI requires no duplicate row checking during loads.
  • A UPI is the Primary Key of the table.
  • A UPI access is a two-AMP operation.

17. What are the two types of Secondary Indexes? (Choose two.)
  • Non-Unique Secondary Indexes
  • Unique Secondary Indexes
  • Partitioned Secondary Indexes
  • Non-Partitioned Secondary Indexes

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