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explain plan [message #65298] Mon, 26 July 2004 03:00 Go to next message
mb
Messages: 51
Registered: March 2001
Member
hi,
would you please explain more abount  coloumn 'OPTIONS' in explain plan .
thanks  a lot
Re: explain plan [message #65299 is a reply to message #65298] Mon, 26 July 2004 07:01 Go to previous messageGo to next message
Frank Naude
Messages: 4565
Registered: April 1998
Senior Member
Hi,

The OPTIONS column (VARCHAR2(255)) describes the options for the OPERATION performed at this step. Example:

SQL> conn / as sysdba
Connected.
SQL> explain plan for select * from tab;

Explained.

SQL> SELECT operation, options FROM plan_table;

OPERATION                      OPTIONS
------------------------------ ------------------------------
SELECT STATEMENT
NESTED LOOPS                   OUTER
TABLE ACCESS                   BY INDEX ROWID
INDEX                          RANGE SCAN
TABLE ACCESS                   CLUSTER
INDEX                          UNIQUE SCAN

6 rows selected.


Best regards.

Frank
Re: explain plan [message #65315 is a reply to message #65299] Fri, 30 July 2004 21:12 Go to previous messageGo to next message
mb
Messages: 51
Registered: March 2001
Member
hi , thanks
but I wanted to know the meaning of
OUER , BY INDEX ROWID , RANGE SCAN,CLUSTER,UNIQUE SCAN
and their differences
thank you
Re: explain plan [message #65343 is a reply to message #65315] Wed, 11 August 2004 04:50 Go to previous message
Frank Naude
Messages: 4565
Registered: April 1998
Senior Member
Hi,

This is clearly documented in the Performance Tuning Guide. In particular, read chapter 9: "Using EXPLAIN PLAN".

Best regards.

Frank
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