Explain EXPLAIN PIPELINE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)
    ExpressionList (children 1)
     Function cityHash64 (children 1)
      ExpressionList (children 1)
       Identifier number
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Function numbers_mt (children 1)
        ExpressionList (children 1)
         Literal UInt64_100
    ExpressionList (children 1)
     Identifier number
    Set
