Re: Insufficient storage of the table data

On 28 Jul 2003 13:38:14 -0700, tcny2k_at_yahoo.com (tcny2k) wrote:

>To all DBA experts,
>
>Recently, I did a query on the DBA_SEGMENTS for a specific table and
>the result showing that 588 extents for that table. The retired DBA
>told me that it's a major concern because it should not pass the
>recomments extents (which is 20).
>
>I was looking for any kind of documents that talks about this but I am
>out of luck. All I can find is pros and cons between large and small
>extents.
>
>Would someone out there help me with this? Would a table with 588
>extents
>be a big concern? Where can find that information?
>
>This is the query that I used:
>> SELECT * from dba_segments where segment_name='HARVERSIONDATA'
>
>SUBSTR(SEGMENT_NAM SUBSTR(TABL BYTES BLOCKS EXTENTS
>INITIAL_EXTENT NEXT_EXTENT PCT_INCREASE
>------------------ ----------- --------- --------- ---------
>-------------- ----------- ------------
>HARVERSIONDATA HARVESTBLOB 18477056 4511 588
>11255808 12288 0
>
>Thanks in advance.

The number of extents really doesn't matter. However, even when you don't use Locally Managed Tablespaces (and it looks like you don't) the initial and next extent preferably should be the same. That said, a next extent of 12k is ridiculous as Oracle will never read more than one extent at a time, and most O/Ses are capable of reading at least 64k with one I/O request

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Mon Jul 28 2003 - 23:29:03 CEST