Explain EXPLAIN (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     Literal UInt64_1
    TablesInSelectQuery (children 2)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Subquery (alias tx) (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 1)
           ExpressionList (children 1)
            Literal UInt64_1
     TablesInSelectQueryElement (children 2)
      TableExpression (children 1)
       TableIdentifier t0
      TableJoin (children 1)
       Literal Bool_1
