Multiple choice technology

Which of the below statement is true?

  1. Row ids are sequential and unique

  2. Row ids are not sequential but unique

  3. Row ids are sequential but not unique

  4. Row ids are neither sequential nor unique
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Database row IDs are guaranteed to be unique but are not sequential. When records are deleted, gaps are created in the sequence. Additionally, concurrent inserts can allocate IDs that don't appear in strictly increasing order. This is true for most database systems including Netezza which uses a unique row identifier system.

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