Re: TRUNCATE TABLE acquire rollback segment?

Tom wrote:
>
> I always thinking TRUNCATE TABLE is fast because no rollback is generated
> for the operation. Suddenly, I found foolowing in COUCHMAN's DBA
> certifaction book:
>
> "Despite your inability to rollback a table truncation, Oracle does acquire
> a rollback segment for the job. Why? Because if you terminate the truncate
> table command, or some failure occurs, the rollback segments stores the
> changes made for the duration of the truncate operation to enable crash
> recovery."
>
> I do not quite understand what information is put in the rollback for the
> TRUNCATE operation. Your help is appreciated.
>
> Tom

Since the truncate will result in the high water mark for the table being altered (ie reset back to 'zero'), this change needs to be able to be rolled back...

Note though that some versions of oracle (8.0.x mainly) will crash the database when a break is attempted during a truncate operation

hth
connor

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Connor McDonald
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"Some days you're the pigeon, some days you're the statue"