Re: too much rollback segment usage

Hi, Jonathan,
Thanks for your reply.

I really like your book, "Practical database 8i", I have already read it three times, and I still need to read it more. Will there be 9i book any time soon?

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:andllh$gfu$1$8302bc10_at_news.demon.co.uk...
>
> It doesn't even store the rowid really,
> just an instruction to eliminate a row
> index entry in a table block. However
> the basic infrastructure of undo (rollback)
> requires about 80 bytes overhead per
> undo record - so your 680MB for 10M
> single row inserts is a bit on the small
> side.
>
>
>
> --
> Regards
>
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk
>
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>
> charlie cs wrote in message ...
> >too much rollback segment usage
> >
> >I was doing
> >SQL> desc test
> >Name Null? Type
>
>----------------------------------------- -------- ------------------------
> -
> >---
> >DASET_ID NOT NULL NUMBER(10)
> >SECT_ID NOT NULL NUMBER(10)
> >
> >begin
> >for i in 1 .. 10000000 loop
> >insert into test values (i,1);
> >end loop;
> >commit;
> >end;
> >/
> >PL/SQL procedure successfully completed.
> >
> >After it finish, the highwater mark of table is only 150M, but during the
> >inserts, rollback segments grow up to 680M, why do we need such a big
> >rollback segments for such a small table? According to some OCP book,
> >insert only store new rowid into the rollback segments.
> >
> >Thanks for your help.
> >
> >by the way, there is no indexes on the table
> >
> >
> >
>
>
Received on Wed Oct 02 2002 - 05:55:53 CDT