Explain EXPLAIN QUERY TREE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 3)
           ExpressionList (children 1)
            Asterisk
           TablesInSelectQuery (children 1)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              TableIdentifier bug
           Function or (children 1)
            ExpressionList (children 3)
             Function equals (children 1)
              ExpressionList (children 2)
               Identifier k
               Literal UInt64_1
             Function equals (children 1)
              ExpressionList (children 2)
               Identifier k
               Literal UInt64_2
             Function equals (children 1)
              ExpressionList (children 2)
               Identifier k
               Literal UInt64_3
    Function or (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier s
        Literal UInt64_21
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier s
        Literal UInt64_22
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier s
        Literal UInt64_23
    Set
