Re: Oracle9.2: Data segment compression bug

dias wrote:
>
> Hi,
>
> There is a whitepaper at this address :
>
> http://otn.oracle.com/products/bi/pdf/o9ir2_compression_twp.pdf
>
> Do you know which dictionary table or view indicates that a table is
> compressed or not ?
>
> Thanks
>
> "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:<ar2887$cv4$1$8302bc10_at_news.demon.co.uk>...
> > It's not a but, it's expected behaviour.
> >
> > The documentation is almost non-existent,
> > but you're only expected to compress tables
> > (or partitions) before making them read-only.
> >
> > You should also note that when you compress
> > a table, the PCTFREE switches to zero - it's a
> > little clue that you aren't expected to do any
> > normal DML on the table.
> >
> > I believe there may be a whitepaper about it on
> > OTN by now.
> >
> > --
> > 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 (Detroit)
> > ____USA__________November 19/21 (Dallas)
> > ____England______November 12/14
> >
> > The Co-operative Oracle Users' FAQ
> > http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> >
> >
> >
> >
> >
> > Vsevolod Afanassiev wrote in message
> > <4f7d504c.0211142142.4c1b75d4_at_posting.google.com>...
> > >It seems that when a table is created with COMPRESS attribute
> > >and then populated via conventional INSERT, the
> > >compression does not work. However, if a table
> > >is populated via direct load insert (using SQL*Loader or /*+ APPEND
> > */
> > >hint), then compression works.
> > >This can be seen from the fact that the segment size is approx. twice
> > >smaller (table consists of multiple small extents of the same size).
> > >
> > >After a table is created, then
> > >ALTER TABLE name MOVE COMPRESS;
> > >will compress it no matter how it was created.
> > >
> > >The happens for both partitioned and non-partitioned tables
> > >and locally managed and dictionary-managed tablespaces.
> > >
> > >Environment:
> > >Sun Solaris 8
> > >Oracle 9.2.0.2.0 (32bit), 16k blocks

Its not there in xxx_TABLES (once again a bug) but if you look at the definition for xxx_TAB_PARTITIONS (where it IS there), you can see that its just an attribute within SEG$

hth
connor

-- 
==============================
Connor McDonald

http://www.oracledba.co.uk

"Some days you're the pigeon, some days you're the statue..."