Re: DDL/DML and rollback

In article <cu4l4d$pq0$1_at_nemesis.news.tpi.pl>, vertigo says...
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>> Think of it: when your database crashes during drop table, and the DDL
>> hasn't been yet automatically committed, shouldn't Oracle be capable
>> to rollback the operation?
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>Ok, but what about truncate:
>I found that: 'truncate is a DDL statement and generates no rollback
>information'. What happen when database crashes during truncate table ?
>

there is no undo generated for the segment being truncated (no need, the data is left untouched on disk)

however, the dictionary updates that take place generate UNDO - so that in the event of a crash in the middle of the truncate (before it completes, before it commits) -- the database will be able to "undo" the partial truncate.

>Thanx
>Michal
>

-- 
Thomas Kyte
Oracle Public Sector
http://asktom.oracle.com/
opinions are my own and may not reflect those of Oracle Corporation