Getting the actual size of the result of a query

Question

Hi,
I would like to ask if someone knows on how to get an estimate size of the result of a query on a table. To make it more specific, here is an example.
Let us say I have this table called EMP and it has a column called DATE. I have issued a query like this:
select * from EMP where DATE < to_date('01-AUG-08');
I want to get the actual size of the result of the query in bytes or MB. How would i achieve this without creating another table and transferring the data on it.

Answer 1

You can use SQL*Plus Autotrace to have the data size sent between client and database session:
SQL> set autotrace traceonly statistics;
SQL> select * from employees where hire_date < to_date('01/08/08');
107 rows selected.
Statistics
        430  recursive calls
          0  db block gets
        123  consistent gets
         11  physical reads
          0  redo size
       9405  bytes sent via SQL*Net to client
        457  bytes received via SQL*Net from client
          9  SQL*Net roundtrips to/from client
          3  sorts (memory)
          0  sorts (disk)
        107  rows processed
SQL>Edited by: P. Forstmann on 25 janv. 2011 18:55