Re: playing with dbms_rowid

It looks like you may have a 4K block size. In LMTs the first 64K (usually) is taken up by file control data - including the file's bitmap blocks. Block 17 in your case
would be the table's segment header block, leaving block 18 as the first data block in the table.

(Of course, you may have created data where the first row, when ordered by pk, was not the first row in the table - but I'm assuming you didn't).

-- 
Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

April 2004 Iceland  http://www.index.is/oracleday.php
June  2004      UK - Optimising Oracle Seminar


"Ed Stevens" <nospam_at_noway.nohow> wrote in message
news:7hnj60hhnnees8sfua4p9m98d3op03ii4u_at_4ax.com...


> Oracle 8.1.4 on Win2k

>

> Created a test tablespace. LMT w/ uniform extents.

> Created table and pk index in the new TS

> Ran a PL/SQL loop to load the new table with test data.

>

> Then ran the following query:

>

> select  supl_key "key",

> dbms_rowid.rowid_block_number(rowid) "block",

> dbms_rowid.rowid_row_number(rowid) "row"

> from mytable

> order by supl_key

> /

>

> I was somewhat surprised to find that the lowest # block-id was 18.

> Am I right in thinking that blocks 1 thru 17 are used for TS

> management?