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Re: Slowness on insert statemente

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Tue, 17 Aug 2004 07:30:18 -0700
Message-ID: <1092753065.997815@yasure>


mario wrote:

> Il Fri, 13 Aug 2004 05:33:06 -0700, Pete's ha scritto:
>
>

>>"mario" <xnazsco_at_tiscali.it> wrote in message news:<pan.2004.08.12.08.20.00.26204_at_tiscali.it>...
>>
>>>Hi all,
>>>a simple question:
>>>the dimension of a table can directly be responsible
>>>of the slowness of an insertion?
>>>in other words: if I have two identical tables that only
>>>differ for the number of records, it is the insert of one record
>>>slower in the big table regarding the small?
>>>
>>>thank's
>>
>>The table that is experiencing the slow insert, have there been many
>>deletes on this table?  You may be getting some free list contention. 
>>Also, how many indexes on this table are there vs. the one that
>>inserts fast?  If you have many indexes on many different columns,
>>then this will slow the insert down as Oracle will have to insert the
>>data into all the indexes.
>>
>>HTH,
>>Pete's

>
>
>
> Hi,
> the two databases are identical except for the number of records.
> The smallest in fact, has been created from a cold backup of the largest
> one deleting some million of records in order to run some tests faster.
> The physical path of the datafiles are not the same, but I think that
> this is not a problem, because the datafiles are on a netapp filer and
> are mounted via NFS in both the db.
>
> cheers
> M.

Deleting records makes nothing smaller. Truncate table followed by inserting a smaller number of records does but not a delete. My guess is that the high-water mark is exactly where it was and Oracle is still reading all the way to the top.

Run Explain Plan wiht DBMS_XPLAN.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)
Received on Tue Aug 17 2004 - 09:30:18 CDT

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