rollback segment question

[clio_usa]

the main purpose of the system rollback segment is to handle rollback for DDL transactions - that is transactions against the data dictionary tables themselves

Short answer: YES.

It is in regards of DDL against the data dictionary in the SYSTEM tablespace. In this case the rollback segment in the SYSTEM tablespace are used for transactions that occur on objects in the SYSTEM tablespace. That does include DDL and DML statements as well.

For the rest of the DDL in the database no rollback segments are used.

--clio_usa
Senior Oracle DBA



[Edited by clio_usa on 05-17-2002 at 02:27 AM]

[SANJAY_G]

the main purpose of the system rollback segment is to handle rollback for DDL transactions - that is transactions against the data dictionary tables themselves

Do you mean DML on dictionary tables or DDL? I agree that system rollback segment might be used for DML on dictionary tables which is handelled by Oracle.

But I don't think any DDL transaction (create table, create view... etc) use any rollback segment. Because DDLs are implicitely commited and can not be rolled back.

Sanjay

[oravijay]

Hi Sanjay,

Whenever you do any DDL statement, Oracle has to perform some DML activity on the
respective Data Dictionary.

Thanks.
Vijay.

[Tarry]

Originally posted by puneet
Hi

Should SYSTEM RB have an optimal value set like all other Rollback segments . Please let me know

Thanks

Answering the orig Q. The min reqm't is 5mb. You can always alter the storage parameters to match your reqmts.
but if you're creating other tblspaces as well then there is no need to alter the storage parameters(i mean since the time of db creation.. small/med/or large basis).

Cheers!!

Tarry

[stecal]

DDL's have implicit commit statements associated with them. Once a DDL is issued, completed DML statements/transactions are committed. Once committed, what is there to rollback?

[puneet]

Thanks Guys

I get my answer and I am going to change the default tablespace of my users to something other than system and leave the system tablespace as it is .

There was no error it was just that I was verifying that All my Rollbacks have an optimal value when I realised that my system RB had no optimal value , so i thought I will confirm on this .

Hope this makes things clearer.

Thanks

you guys are greeaaaaaaaaaaat .


regards