Re: Oracle8 ROWIDs - data file numbers

In article <89hnid$k2d$1_at_nnrp1.deja.com>,   Ben Ryan <benryan_at_my-deja.com> wrote:
> The New Oracle8 ROWID format
>
> The Oracle8.0 "new features" courses talk about the file number
> component of the ROWID as being the relative data file number within
 the
> tablespace. (In Oracle7 the datafile component of ROWID is the
 absolute
> data file number within the database.)
>
> I cannot produce an example that shows the difference. My attempt
 below
> shows a partitioned table with two partitions containing two rows, one
> in each partition, with each partition being in a different
 tablespace.
> When I compare the relative data file numbers with the absolute data
> file numbers I do not see any difference. I would have expected the
> relative file number to be, say, 1 (meaning first data file within
> tablespace).
>
> Can anyone give me an example which would show the difference.
>

you would have to create a database with lots (thousands) of files. The relative file number will be a 2 byte integer. The absolute file name is a 4 byte integer in 8. The relative will equal the absolute until you get a whole mess of files in there. The relative file number is by tablespace and was kept a short integer to avoid have to change the internal format of a rowid.

> Test is on 8.0.4.
>

 [snip]
>
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> Before you buy.
>

--
Thomas Kyte                              tkyte_at_us.oracle.com
Oracle Service Industries                Reston, VA   USA
--
Opinions are mine and do not necessarily reflect those of Oracle Corp


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