CreateQuery t_array_index (children 3)
 Identifier t_array_index
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration n (children 1)
    DataType Nested (children 1)
     ExpressionList (children 2)
      NameTypePair key (children 1)
       DataType String
      NameTypePair value (children 1)
       DataType String
 Storage definition (children 2)
  Function MergeTree
  Identifier n.key
