On an insert, Oracle only stores a pointer in the RBS to the row inserted.
That's all it needs to "undo" it if you rollback.
Simon Quinn <simon.quinn_at_bigfoot.comX> wrote in message
news:tXzrN65vCQ=kCIKhdpDcnD6une=K_at_4ax.com...
> Perhaps I'm missing something but how come Rollback Segment usage is
> very small or not used when inserting into a table using the normal
> INSERT SQL statement.
>
> All I'm doing is doing:
> INSERT INTO target_table
> SELECT * from source_table;
>
> Testing this with 200,000 rows shows that the rollack segment stays
> small, initially configured to be 4MB but does not increase any
> furthur. If I do a DELETE or UPDATE on these tables the Rollback
> Segment becomes large 250Mbytes+ which is what I would expect.
>
> Tested on 8.0.4 and 8.1.5
>
> What am I missing?
>
> Cheers
> Simon Quinn
Received on Sat Sep 25 1999 - 08:12:33 CDT
