Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 2)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 3)
           ExpressionList (children 2)
            Function toInt8 (alias id) (children 1)
             ExpressionList (children 1)
              Literal UInt64_1
            Function toDate (alias date) (children 1)
             ExpressionList (children 1)
              Literal \'2000-01-01\'
           TablesInSelectQuery (children 1)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              TableIdentifier system.numbers
           Literal UInt64_1
     TablesInSelectQueryElement (children 2)
      TableExpression (children 1)
       Subquery (alias b) (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 2)
           ExpressionList (children 1)
            Asterisk
           TablesInSelectQuery (children 1)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              TableIdentifier test_00597
      TableJoin (children 1)
       ExpressionList (children 2)
        Identifier date
        Identifier id
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier b.date
      Function toDate (children 1)
       ExpressionList (children 1)
        Literal \'2000-01-01\'
