[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] N values recipe  nodes, hierarchies      children          locating immediate      leaf nodes          listing  2nd      listing      parent  nonaggregated columns recipe  nonrecurring events, excluding, recipe  normalized data      attributes      dependent columns and      folding tables and      GroupPermissions table      memory requirements      readability      repeating columns and  NOT EXISTS statement, differences and  NULL values