Which one does not belong

Exercise and reference answers

Questions

1. Items

   1. Relation
   2. Tuple
   3. Recursion

   Odd item

   Recursion

2. Items

   1. Compiler
   2. Degree
   3. Cardinality

   Odd item

   Compiler

3. Items

   1. Primary key
   2. Foreign key
   3. Shortcut key

   Odd item

   Shortcut key

4. Items

   1. Redundancy
   2. Inconsistency
   3. Encryption

   Odd item

   Encryption

Instructions

Tap the item that does not fit with the others.

Explanation