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doubt on rollback segment
Hi..
I'm new to dba.i've a doubt on rollback segment..oracle guru's kindly help me..
Here'z the doubt..
Any DML statements(insert,update,delete) made to any table in the database has a rollback entry..
But even a create tablespace command(which is a DDL) updates the sys owned table 'ts$' in data dictionary. why there are no rollback entries from 'create tablespace' command.??
kindly help..
Rgds,
Sarav
saravana kumar
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Hi
rollback segmenst is used when i want to read consistency..
when you create a tablespace (DDL) ----raed consistency is not requied
when you do a ddl like this...
create table xyz
as
select * from emp --------------This requires read consistancy
hence eevnthough the second is a DDL it uses rollback because the select part has to eb done in read consistent mode..
when you do such opeartion ts$..they are logged in the redologs..not the rollback..
regards
Hrishy
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But pando..i've only studied that only dml statements will have rollback entries..thatz why you can rollback.
but,since ddl statements dont have a rollback entries,they cannot be rolled back.
Rgds,
sarav
saravana kumar
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well
imagine you have to alter a 100000 millions of table, alter is DDL, what happens if during your alter the databse dies? you cannot rollback but Oracle can
Last edited by pando; 05-16-2003 at 06:31 AM.
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hey..ur answer sounds good.but can u give me a perfect answer.
tell me what happens when u give a ddl(create,alter,drop) and when you give an dml(insert,update,delete).
will there be rollback entries generated for the dml and ddl comands?
rgds,
sarav
saravana kumar
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dont know what are you talking about
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Originally posted by ksarav
hey..ur answer sounds good.but can u give me a perfect answer.
tell me what happens when u give a ddl(create,alter,drop) and when you give an dml(insert,update,delete).
will there be rollback entries generated for the dml and ddl comands?
rgds,
sarav
Read this...
http://asktom.oracle.com/pls/ask/f?p...2860243091362,
Amar
"There is a difference between knowing the path and walking the path."
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thanks for that article..it was really great..
thanks adewri..
rgds,
sarav
saravana kumar
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