Extent allocation (New DBA Question)

From: Lindsay Stoddard <lindsay.stoddard_at_osha-slc.gov>
Date: Tue, 16 May 2000 13:20:53 -0500
Message-Id: <10499.105771@fatcity.com>

Hi,

I am using the following SELECT statement to obtain space information about table objects:

COL Segment_Name FORMAT a25 HEADING "Table Name" COL Tablespace_Name FORMAT a10 HEADING "Tablespace" COL Bytes FORMAT 99,999,999 HEADING "Bytes" COL Blocks FORMAT 9,999,999 HEADING "Blocks" COL Extents FORMAT 99,999 HEADING "Extents" COL Next_Extent FORMAT 99,999,999 HEADING "Next Extent" COL Initial_Extent FORMAT 99,999,999 HEADING "Initial Extent"

SELECT Segment_Name,

       Tablespace_Name,
       Bytes,
       Blocks,
       Extents,
       Initial_Extent,
       Next_Extent

  FROM DBA_SEGMENTS
 WHERE Owner = UPPER('&&owner')
   AND segment_type = 'TABLE'
 ORDER BY Segment_Name;

One of the rows returned from this SELECT is:

Table Name                Tablespace       Bytes     Blocks Extents Initial

Extent Next Extent

------------------------- ---------- ----------- ---------- ------- --------
------ -----------
PART_NO                   USERS           81,920         10       1
57,344      57,344

The database has a db block size of 8K.

I am wondering why only one extent is being used although the "Bytes" being used is more than the "Initial Extent". The initial extent is equal to 7 blocks at 8K a piece. My thinking is that another extent would have been used once the Bytes went over 57,344 and Blocks would be 14. To me, Blocks should be 7 or 14 etc. Whats happening?

Thanks to anyone who can help, Received on Tue May 16 2000 - 13:20:53 CDT