SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function equals (children 1)
     ExpressionList (children 2)
      Function count (children 1)
       ExpressionList
      Literal UInt64_1
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Asterisk
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             Function viewExplain (children 1)
              ExpressionList (children 3)
               Literal \'EXPLAIN ESTIMATE\'
               Literal \'\'
               Subquery (children 1)
                SelectWithUnionQuery (children 1)
                 ExpressionList (children 1)
                  SelectQuery (children 2)
                   ExpressionList (children 1)
                    Function sum (children 1)
                     ExpressionList (children 1)
                      Identifier a
                   TablesInSelectQuery (children 1)
                    TablesInSelectQueryElement (children 1)
                     TableExpression (children 1)
                      TableIdentifier t1
