SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function trimLeft (children 1)
     ExpressionList (children 1)
      Asterisk
   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\'
               Literal \'\'
               Subquery (children 1)
                SelectWithUnionQuery (children 1)
                 ExpressionList (children 1)
                  SelectQuery (children 6)
                   ExpressionList (children 1)
                    Function sum (children 1)
                     ExpressionList (children 1)
                      Identifier b
                   TablesInSelectQuery (children 1)
                    TablesInSelectQueryElement (children 1)
                     TableExpression (children 1)
                      TableIdentifier pr_t
                   ExpressionList (children 1)
                    Identifier a
                   ExpressionList (children 1)
                    OrderByElement (children 1)
                     Identifier a
                   Literal UInt64_500
                   Literal UInt64_5
   Function like (children 1)
    ExpressionList (children 2)
     Identifier explain
     Literal \'%ReadFromMergeTree%\'
