Re: too much rollback segment usage

"Howard J. Rogers" wrote:

> Actually, it *is* a 9i book.
>
> In one or two crucial areas (automatic PGA and automatic undo spring to
> mind), 8i and 9i are profoundly different, and the outcomes are
> correspondingly diverse. But as far as 98% of everything Jonathan wrote
> about, it's much of a muchness (index behaviour hasn't changed drastically,
> for example, between versions).
>
> His publisher should be shot for daring to include the killer words "8i" in
> the book's title. Instant consignment to the 'remainder' bin, for absolutely
> no good reason.
>
> Regards
> HJR
>
> "charlie cs" <cs3526_at_ureach.com> wrote in message
> news:ZgAm9.18757$1F3.11737_at_nwrddc02.gnilink.net...
> > Hi, Jonathan,
> > Thanks for your reply.
> >
> > I really like your book, "Practical database 8i", I have already read it
> > three times, and I still need to read it more. Will there be 9i book any
> > time soon?
> >
> >
> > "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message
> > news:andllh$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
> > >
> > > Next Seminar dates:
> > > (see http://www.jlcomp.demon.co.uk/seminar.html )
> > >
> > > ____USA__________November 7/9 (MI), 19/21 (TX)
> > > ____England______November 12/14
> > >
> > > The Co-operative Oracle Users' FAQ
> > > http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > 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
> > > >
> > > >
> > > >
> > >
> > >
> >
> >

Alas, Howard you're not a marketer. The publisher will ask Jonathan to make a few small changes, write a couple of paragraphs to promote the "NEW" book to Amazon.com, invest a few dollars in a new cover with 9i prominently displayed, and sell another book to the same people so happy with Jonathan's last book that they will buy anything they see with his name on it.

Then they will congratulate themselves on their improved bottom line and anxiously await the release date of 10i so they can do it all over again.

Great book Jonathan. I keep a copy within arms reach too.

Daniel Morgan Received on Wed Oct 02 2002 - 10:38:03 CDT