Explain plan only in spool file

Question

Hi there,
I am trying to spool only my explain plan to a file, at the moment i can only return all the results and then explain plan to the file. This is a bit of a problem as i am running some rather long queries and some of them return over 80MB of data. this is what i have so far:
set termout off
timing start
set autotrace on
set heading off
spool h:\test1.lst
select unique1 from table1;
timing stop
spool off
set autotrace off
set termout on
any help on this would be great.
Thanks!

Answer 1

Or for a handy way to preview the expected plan without executing the query, try www.williamrobertson.net/code/xplan.sql
SQL> SELECT COUNT(*) FROM dept d
  2  WHERE  EXISTS
  3         ( SELECT NULL FROM emp e
  4           WHERE  e.deptno = d.deptno )
  5 
SQL> -- Note we did not execute anything...
SQL> @xplan
Plan hash value: 4196393176
| Id  | Operation            | Name    | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT     |         |     1 |     6 |     4  (25)| 00:00:01 |
|   1 |  SORT AGGREGATE      |         |     1 |     6 |            |          |
|   2 |   NESTED LOOPS       |         |     3 |    18 |     4  (25)| 00:00:01 |
|   3 |    SORT UNIQUE       |         |    14 |    42 |     3   (0)| 00:00:01 |
|   4 |     TABLE ACCESS FULL| EMP     |    14 |    42 |     3   (0)| 00:00:01 |
|*  5 |    INDEX UNIQUE SCAN | PK_DEPT |     1 |     3 |     0   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   5 - access("E"."DEPTNO"="D"."DEPTNO")
SQL> -- And the query is still there:
SQL> l
  1  SELECT COUNT(*) FROM dept d
  2  WHERE  EXISTS
  3         ( SELECT NULL FROM emp e
  4*          WHERE  e.deptno = d.deptno )